Challenge I - Aperture and Depth of Field

[ricktas]

Our first challenge to our members that want to learn to take control of their digital camera is based on the Learning Centre topic : Experimenting with Aperture (http://www.ausphotography.net.au/forum/showthread.php?t=24050)

We would like you to set your camera to Aperture mode (sometimes called A or Av mode). Check your camera manual in need, on how to set your camera to Aperture mode.

We want you to go out and take two photos of the same subject. One at the largest aperture your lens will allow and one at the smallest. So take one photo at f4.5 and one at f22, of the same subject. Then post both photos in this thread, with comments about what differences you notice between the two photos.

[clm738]

f4.5
only Noah in focus
shutter 1/160
file size 63.4kb

f22
more people in focus
shutter 1/6
file size 85.7kb

[clm738]

Have now also noticed exposure difference

[Jcas]

F4.5 Background not focused
F22 Background in focus.

[bigdazzler]

with these, remember distance between subject and background has a great effect on DOF also ..

[ricktas]

So if you wanted to take a nice portrait shot of a friend, given the above tests, what aperture would you use, and how would you place your subject in relation to the background?

[Seven]

Im thinking with portraits the background needs to be blurry in someway.

So I would have a f4.5 to 8 and try to have the backdrop blurred out. If I was to have a high f20 or something the background would be more in focus and take away from the portrait.

However if there was something nice behind them or it was a portrait of someone standing in front of a place of interest eg holiday snaps of places you have been I would select the background to be blurred. Slightly maybe but not as much if I was taking a portrait.

I would hopefully still in a portrait get something with structure behind them like nice set of rocks or colored things that don't over power the person.

Oh and focus on the eyes and nose with spot meter to grab the settings based on the important part. Probably would try to get lighting right and find out side better as still getting used to flashes

[Seven]

Went out and did the challenge and found some interesting things that I worked out.

First photos definitely showed how you can get blurred back ground to keep the attention on the part of picture you want the attention.

The second set shows when working with a flash how it totally affects the photo contrast. I was amazed at the level of contrast difference and it also gave me a better understanding of focal points of the lenses.

I also found that the lens needed at least a few cms of distance between the point of interest to the focused part. Yet with my bigger zoom lens its not as bad.

Further more to previous post I would also have at least 30cm to 1 mt distance between background and the portrait shot.


I also cropped in on the leave to show some sort of reasoning behind just cropping the point of interest, but still having a blurred background

Something I also noticed was that the image slightly looked a bit more zoomed in with out changing the zoom and not quite sure why?

[clm738]

Hi Rick
I would use a large aperture and place them some distance from the background to make it more OOF.

[NikonNellie]

With a close portrait you would want your subject to be the main point of interest and your background OOF so that the viewer's eye is not distracted elsewhere in the shot. I would therefore set my aperture to the largest setting that the camera would allow, e.g f4.5 ( even larger if your camera will allow it). I would have them standing close to the background.
If you want your subject to be a part of a scene ( say standing in front of an historic building) then I would have them stand further away from the background and set my aperture to a smaller setting e.g. f22, critically focus on my subject and not the building. I should then have a shot where both my subject and the background are in focus.
I HOPE THIS IS CORRECT!

[NikonNellie]

42 Degrees in Sydney today so I did not venture outside to take my photos instead I took a couple of shots inside. The first one was f5.6, which was the largest aperture my lens would allow. The second photo was f22. Both photos had an ISO of 125 and I used the natural light coming in through the window. The venetian blinds are probably not the best background but you can distinguish that one background is crisper than the other.

[ricktas]

Good work everyone. So now you are learning what Aperture does, and will be able to creatively use it to change the way your photo looks. It is a bit more complex than just choosing an aperture though.

The other parts of the equation is the distances objects are from the camera, AND the aperture selected. Remember DOF means Depth Of Field, the distance front to back in your photo that will be in focus, from the focal point, at a given aperture. The last component to affect the DOF, is the focal length of a lens, a Lens at 50mm and f4.0 will have a different DOF to the same lens at 200mm and f4.0

Take this example:

Your subject is 2 metres from your camera
You are using a 50mm f1.8 lens (the great standard portrait lens) and its reasonably cheap to buy.

Here is a chart that shows what happens as you change aperture:

At F1.8 you focus on the subject at 2 metres, your DOF will be from 1.92m - 2.09m
At F2.8 you focus on the subject at 2 metres, your DOF will be from 1.87m - 2.14m
At F4.5 you focus on the subject at 2 metres, your DOF will be from 1.81m - 2.24m
At F8.0 you focus on the subject at 2 metres, your DOF will be from 1.68m - 2.48m
At F16.0 you focus on the subject at 2 metres, your DOF will be from 1.45m - 3.25m

So as you go to a smaller Aperture (larger F number) the distance front to back that is in focus is greater, so to effectively blur your background, you background will need to be further back from your subject.

But there is another additional aspect, and that is how far your subject is from you. Taking the example above again, but moving your subject to 5 metres away.

At F1.8 you focus on the subject at 5 metres, your DOF will be from 4.51m - 5.61m
At F2.8 you focus on the subject at 5 metres, your DOF will be from 3.94m - 6.85m
At F16.0 you focus on the subject at 5 metres, your DOF will be from 2.55m - 122.45m

So the further the distance from the camera to the subject, the greater the DOF.

Using Aperture effectively takes practice to know when to use it, how to use it and how to judge the DOF for your setting, so that you can make the background sharp or blurry, as you intend.

You can get small software programmes that calculate the DOF, using the focal length (lens), Aperture and subject distance. With that information they can calculate the near DOF limit, the Far DOF limit, the total depth and more. But who wants to cart a laptop and run some software everytime they need to know a DOF? The best way is to get out and practice in the real world, and learn from your results.

There several other factors that affect DOF, including the camera you are using (sensor size), There is quite a good DOF calculator here (http://www.cambridgeincolour.com/tutorials/DOF-calculator.htm), but don't get to hung up on using it, try it to get an understanding, but you will learn more by getting out with your camera and taking shots for yourself.

[clm738]

Thanks Rick. What I do is to take most photos using a small aperture then the same photo using a large aperture and compare the two to try and learn how much is in focus and how to get the effect I want.Oh the joy of digital!!!

[Nanny]

I can see the difference in the background
in the first the background is blurred and the second is focused
and there is a difference in shutter speed.

[ricktas]

When in Av mode (aperture mode) and you change the aperture, the shutter speed adjusts accordingly, by the camera. At f4.5 the aperture is wide open so a lot of light can come through the lens to hit the sensor. The camera knows this so will select a faster shutter speed to ensure a correct exposure. When you take your shot at f22, the aperture opening is tiny, and the camera compensates by slowing the shutter speed to allow enough light through the small aperture, to again get a correct exposure.

Nanny has commented on this, and it teaches you that shutter speed and aperture are inter-related. When you start using manual mode, you will have to select both the aperture and the shutter speed. So it is worth understanding the relationship between the two now, while we are still working in Aperture mode.

[Nic076]

Great thread Rick. I have seen the difference quite a few times in many of my photos when I want a little more detail but suddenly need to be aware of the amount of light on the subject. Generally I have had to up the ISO to compensate.

I also took some photos for a friend a little while ago of her little girl. We were at a park and it was quite bright, and the lens I was using, although set to largest aperture was catching too much background detail. I then realised what you just mentioned about distance. By changing where she was sitting and how close the trees were behind her I managed to get them quite a bit OOF. It was really just trial and error at the time, but a good tip to remember.

[Jcas]

Thanks for the example, it all helps, cute little girl too :)

[lourdes]

Thank you for this, i can see it now.

[ricktas]

Does anyone have any questions regarding Aperture and using Av mode? Please feel free to ask anything. Even if you think its a silly question. The only way to get the answer is to ask.

[chelle]

i had a play with the aperture today (got myself a camera but i'll talk about that later... this first challenge is more interesting).
I noticed a few fun things. I knew what to expect already having read this thread but i took a gazillion photos of all sorts of different things just to see what happened.
These are my most "ah ha" moments....

The mandarin tree gave the proper result IMO. Small aperture, nice small focus area with the background nice and blurry.

But the ones of DS2 at the fence was interesting to me cos it showed me how much a plain boring photo could still be improved just by using a different aperture. The blurry large aperture photo reminds me of some of the results i got from my p&s and the smaller aperture photo has so much more definition in the subject.

And then the one i took inside in a lower light situation was really cool. It is something that i am going to make a mental note of and play around with in the future. The ghost image sort of effort makes me wonder if there are situations where i could do this deliberately ... ? Maybe not! LOL! but if i get a tripod down the track it's something i might fiddle with. Either way it made it totally obvious how the increased shutter opening time is effected by changing the aperture.

[chelle]

here are the indoor ones...

[Dizzy Photographics]

Though i can't participate in this part of things cause i am still without my camera, i am still looking and seeing what everyone is posting. I noticed with NikonNellies shots, that with the 1st image, the subject is actually brighter than in the 2nd one..looks better i think too

Just my lil bit of input...i feel so left out not being able to post something lol :P

[Kym]

Though i can't participate in this part of things cause i am still without my camera, i am still looking and seeing what everyone is posting. I noticed with NikonNellies shots, that with the 1st image, the subject is actually brighter than in the 2nd one..looks better i think too
Just my lil bit of input...i feel so left out not being able to post something lol :P

You can in your Fuj ... it has a Av mode!

[Dizzy Photographics]

yup...dont have it at the moment either...though its only out on loan not broken :D

I have done this already with the fuji...was the very first task you set me Kym lol...

[bigdazzler]

ok heres a real quick one I did to show the differences in DOF you can achieve with a large Aperture ( or commonly called " fast " lens ) lens ..

All pictures were taken in Av mode, on AUTO ISO , which the camera decided was going to be 400

#1. I chose the largest Aperture my lense was capable of, f1.4. The camera chose 1/40th sec for shutter speed. I focused on the front wheel to emphasise that with such a large Aperture the DOF can be very very shallow and some parts of your subject can be out of focus. Also as you can see the background is very very blurry.

http://i445.photobucket.com/albums/qq176/DarrenGrayPhotography/DSC07231.jpg

#2. Aperture of f2.8 , camera chose 1/13th shutter speed. A slight increase in DOF, more of the ferrari is in focus and background a little less blurry.

http://i445.photobucket.com/albums/qq176/DarrenGrayPhotography/DSC07232.jpg

#3. Aperture f11, shutter speed 1.3 seconds. You can see that when stopping down the aperture significantly to f11 , the corresponding shutter speed is also a lot slower at 1.3 secs. These kinds of shutter speeds you cant hand hold without getting camera shake so you will need a tripod ( as i did with this shot ) or find something to brace and support your camera on. Now at f11 you can see a clear increase in the DOF front to back and a lot less blur in the background

http://i445.photobucket.com/albums/qq176/DarrenGrayPhotography/DSC07233.jpg

#4 is aperture f22, and the shutter speed is significantly slower again at a full 5 seconds.
Now the entire frame front to back is in sharp focus.

http://i445.photobucket.com/albums/qq176/DarrenGrayPhotography/DSC07234.jpg

Hope this helps out a little :)

[NikonNellie]

Thanks Darren - that was very helpful. What's that saying " a picture speaks a thousand words".

[bigdazzler]

no worries Nellie .. i just thought that most people who are new to the sport might be using kit lenses with max apertures of about 3.5 , i thought i could demonstrate what a faster lens with max ap. of 2.8 or even 1.4 could achieve in terms of DOF .. Glad it helped :)

oh and by the way i loved your clarinet shot .. very nice and a good example of what were doing here :)

[Jcas]

Great examples Darren, well illustrated and explained .... many thanks:)

[chelle]

i just thought that most people who are new to the sport might be using kit lenses with max apertures of about 3.5 , i thought i could demonstrate what a faster lens with max ap. of 2.8 or even 1.4 could achieve in terms of DOF thanks! that is great to see. i think i have a max ap of 5.6 on mine at the moment (although i think i may have gotten in lower than that when i was playing with something else as well... will have to check). The difference between your first two shots is amazing. The larger ap makes the first photo a great one while the others are just photos of a car! :)

[clm738]

Thanks Darren.

[bigdazzler]

thanks! that is great to see. i think i have a max ap of 5.6 on mine at the moment (although i think i may have gotten in lower than that when i was playing with something else as well... will have to check). The difference between your first two shots is amazing. The larger ap makes the first photo a great one while the others are just photos of a car! :)

i assume youre using the 18-70 kit lense that came with your A300 chelle ??

With most entry level and kit zoom lenses which have variable focal lengths, you will mostly see a bracketed aperture number on the lens. The bracketed aperture numbers relate directly to the different focal lengths of the lens.

Put very simply, your kit lens zoom range is 18-70mm , and the capable aperture of the lens is f3.5-f5.6

f3.5 is the maximum aperture your lens can achieve at its widest end, 18mm. f5.6 is the max aperture the lens can achieve at the long end, being 70mm.

So when you say that the largest aperture you could get when you were playing around was f5.6, in this case your lens would have been zoomed in to 70mm .. and the reason you think you remember getting to a lower f number was actually because your lens was probably at a focal length somewhere in between 18 and 70mm .. does that make sense ??

at the short, or wide end of the lense (18mm) you will be able to get f3.5 , now remember that LOWER or SMALLER f numbers mean LARGER apertures, so therefore f3.5 is the largest aperture your kit lens can achieve

Hope that wasnt too confusing :)

[Becstarr]

Thanks Darren for the great examples I am going to try and set up a similar setting and see how mine turn out

[bigdazzler]

Remember that this exercise relates to how changing your aperture affects DOF. So when setting up your shot make sure you use the same focal length for each shot and only alter your aperture setting, dont move your zoom.

Reason is focal length affects DOF so changing your zoom between shots will affect your DOF and you wont really know what true affect your aperture selection is having,

My examples were shot with a 50mm prime lens ( fixed focal length ) , i realise not everyone will have one of these types of lenses so just set your lense to one focal length and leave it there , only changing your aperture between shots.

Looking forward to seeing some more examples .. Keep up the good work !! :th3:

[Dan AU]

Here are my contributions..

Didn't use a telephoto though so the DOF is not quite as blurry as it could be.

The lens used EF-S18-55mm f/3.5-5.6 IS

Differences is that one is more blurred toward the rear with a smaller aperture f4.5? and clearer with a larger aperture f27,(Not sure if I have the larger and smaller thing the correct way around) You can see a lot more details.

[chelle]

how did you get it to only blur at the rear?

[bigdazzler]

youre on the right track there Dan .. but you got the f numbers around the wrong way ;)

*SMALLER NUMBERS= LARGER APERTURES = BLURRIER BACKGROUNDS

*LARGER NUMBERS = SMALLER APERTURES = LESSY BLURRY BACKGROUNDS/SHARPER FOCUS FRONT TO BACK

you can definitely see the difference in DOF in your subject and background .. good job :th3:

[ricktas]

how did you get it to only blur at the rear?

That is the key! Selecting the RIGHT aperture for the job. Dan got lucky, or he knows more than he is letting on. As you learn to use aperture more, you will be able to reasonably predict the depth of field (distance front to back in focus, from your focus point), and get creative by keeping what you want in focus, and blurring the bits you want as well.

[chelle]

oh, i'm stuck!! i thought that the centre of the photo was focused on and clear and all the surroundings out of focus.... or was the photo cropped at the bottom?? Or are you actually saying that you can choose where in the image the focus is? Or does it just look that way cos the bottom of the photo is black??

[chelle]

oh, oh, oh!!! i think i get it. The worm head is all the same distance from the camera!! It might be up and down in the photo (ie there is height to it) but there is no depth! Ah!!! That probably makes no sense but it does in my head and now i think i understand.

[NikonNellie]

Thanks Darren - I was pretty pleased with the shot. I used my new Tamron 90mm macro lens.

[bigdazzler]

Or are you actually saying that you can choose where in the image the focus is?

yep you sure can .. :D This part is where your different focusing techniques come into it and play a bit of a role in how the DOF in your picture will look.

When you choose a large aperture , and create a shallow DOF, the area of sharp focus in your frame will be shallower, front to back. Thats why the body of Dans colourful animal thingy is blurred.

The head is in focus because thats the part of the subject he has focused on. If hed focused the camera further back along the body, you would see the opposite, the body would be sharp and the head blurry. Make sense ??

Your camera has three different AF ( Autofocus ) modes. Spot, Continuous, Automatic.

You will mostly use spot focus for now and thats how you can produce something like Dan has here.

Set your camera to spot focus, select a large Aperture, look through your viewfinder and you will see a small red square in the middle of the viewfinder, place that square on the part in the scene that you want to be in sharp focus, half press the shutter button until you hear a beep, this beep indicates that the camera has AFed on that point, now reframe your shot to how you want the final picture to look whilst still half pressing the shutter button down, then shoot your picture. Your result should see your focal point nice and sharp and a nice degree of blurred surrounds.

Heres an example of how your DOF can look different in your pictures by altering the point of focus within the frame,
All 3 shots were taken in Av mode, with the same aperture each time of f1.4. I did this at f1.4 because this large aperture creates a very shallow DOF to make the differences more obvious to the eye

#1. The focus point was on the front lens in the foreground, as you can see the lens is sharp and everything else is blurred from about the middle to the rear of the frame.

http://i445.photobucket.com/albums/qq176/DarrenGrayPhotography/DSC07295.jpg

#2. The focus point was the lens further back in the centre of the frame. This lens is now sharp and both the foreground and the background is blurred. The aperture used is exactly the same as the first shot, only the focus point has changed.

http://i445.photobucket.com/albums/qq176/DarrenGrayPhotography/DSC07296.jpg

#3. This time the focus is on the rear lens. Now the foreground and middle of the frame is blurred and the rear lens is sharp and in focus.

http://i445.photobucket.com/albums/qq176/DarrenGrayPhotography/DSC07297.jpg

All three shots were taken with the same large aperture of f1.4 , only the focus point has changed from shot to shot. This demonstrates how critical it is to get your focus spot on when playing with shallow DOF and when you might want a lot of blur in a particular part of your picture ... :)

and PS .. apologies for the horrible white balance .. it is midnight and i just cant be bothered :p

[ricktas]

oh, i'm stuck!! i thought that the centre of the photo was focused on and clear and all the surroundings out of focus.... or was the photo cropped at the bottom?? Or are you actually saying that you can choose where in the image the focus is? Or does it just look that way cos the bottom of the photo is black??

Depends on your Camera Chelle. As far as I know the Sony has focus points. When you look through your lens and press the shutter button part way, do you see a red dot, square light up in the lens, (might be a different colour). That is your focus point. You should have several of these and you can select them.

Someone who uses Sony, might be able to give you a more detailed reply on what they look like and how to change your focus point.

What they enable to you to is focus on something that is not necessarily central in your lens. The other way, is to press the shutter button half way down till focus locks, hold the shutter, recompose your scene, then press the shutter button down fully. That will mean that the item you focused on originally will be in focus, but won't be in the centre of your photo.

[chelle]

oh, that is so bloody obvious now! even my old p&s let me half-click and then move to reframe the shot. Idiot! And i have been doing that with the Sony when taking happy-snaps in Auto mode but never even thought to trial it with the aperture challenge and see what happened.

Off i go to try for myself.....

[Dan AU]

Thanks bigdazzler, I thought I may have had it the wrong way around, confusing stuff sometimes.

The blurred at rear would say is more luck than anything, all I did was set it up on tripod left everything the same and changed the aperture. I think I may have had spot metering on as well for a test.

And I always shoot in manual mode to get into the habit of it, if you asked me to explain how the rear focussing has occured I wouldn't know where to start.

[mrsgrumblebum]

http://i107.photobucket.com/albums/m302/mrsgrumblebum/ausphotography/IMG_5009.jpg

http://i107.photobucket.com/albums/m302/mrsgrumblebum/ausphotography/IMG_5008.jpg

first image f22
I see that the pegs are all in focus as well as the back ground

second image f4.5
I can notice the difference that the pegs starty out clear and then there is a blurring effect as well as a blurry back ground

[anne-1303]

I have read through the experimenting with aperture learning centre, and have been out practicing today :) I am pretty pleased with the results, have definately learnt alot today, and probably more from reading through this learning centre and through the posts on this tread and practicing than I have learnt in the last year !!! I am not sure how to post my photos on here for everyone to have a look at though..... will have to learn how to do that so I can get some feedback on my pics.
Sharon

[ricktas]

Anne, do you have a website, or somewhere like Flickr, that you post your photos to. You can use those to link your photos into your posts, how to is here (http://www.ausphotography.net.au/forum/showthread.php?t=24694)

If you don't, it is worth considering signing up for one of the sites in that thread. Otherwise you can post them direct with your post. Click "post reply", then type your text in the white box, scroll down and click the manage attachments button to add your photos. Note you cannot do this with the Q.reply button.

We prefer members to use the linking method shown above, as this saves on site running costs.

Hope that is easy to follow.

[marko]

Being a recent newcomer to photography, this forum is exactly what I needed.
I've been wandering the internet searching for various topics as I get stuck, but this puts all the key topics in a single location. Laid out in an easy to follow format.
Brilliant work by those involved in setting it up. :th3:


Today I found some spare time while at work to tinker with the apeture exercise.
My workplace is a little different to most, in that I'm located on the water, on a fairly unique vessel.
As such, my subjects are whatever I spot onboard that suits the given exercise.

Here are a couple of objects that caught my eye while thinking about todays readings on Apeture.

All the points about DOF, focal points and exposure length have been raised.
I found this exercise a practical opportunity to observe how the focal depth varies with apeture changes. Although I was aware of how apeture could affect this, It was never so obvious in my own shots until I made this deliberate attempt at the same shot with different settings.

This chain barrier with an apeture of f22 has no defined focal point. The whole image is clear. Useful if multiple objects exist in frame that you want to show in your photo.
Drop the apeture to f5.6 and only a single mid chainlink is in full focus. This lets the chain draw your eyes along the picture as it slowly drifts out of focus.

http://farm4.static.flickr.com/3410/3246340109_3b196be8fa.jpg http://farm4.static.flickr.com/3434/3247165556_8c0350f26a.jpg

http://farm4.static.flickr.com/3409/3246336147_a7f331cd1d.jpg http://farm4.static.flickr.com/3504/3247154780_cbfa4dd7e8.jpg

[ricktas]

Glad you have found what you have been seeking on Ausphotography Marko. Thanks for the feedback on the way we built our learning centre as well. Always nice to know we have succeeded.

Well done on trying the aperture challenge and gaining an insight into how aperture can help you create some truly creative shots.

[anne-1303]

Ok, here goes. I have created a flicka account and am now attempting to link my photos to here for everyone to see. I hope I am doing this right...... Hope I have resized these right so they are the right size required on here?? If I have done something wrong could someone please let me know :confused013 At least I have got them appearing on here !!! :) http://farm4.static.flickr.com/3312/3246525833_8cc675d3eb_o.jpg
http://farm4.static.flickr.com/3470/3247353570_da919c744b_o.jpg

[chelle]

hey marko, i think i am going to like looking at some of your photos.
Usually i have been preferring the photos when there is a much smaller focus area but your second set of images just shows how sometimes the photo can be much more effective with the larger f setting. thanks.

[ricktas]

Good work Anne, now from your challenge photos, have you gained an understanding of how aperture can affect the result?

[Jcas]

I am enjoying seeing peoples creativeness with this thread, some of the examples used are great, the clothes pegs, the chains, the fluffy toys, the lenses and the list goes on:)

Well done all.

[learn2shoot]

what a fantastic challenge. I think this is great way to get the info to "sink in". I will have a go and upload some pics and findings.

[Hobberz]

I am a bit late but thought i would give it a go.

F/22- Subject and backround are in focus, also it is a little over exposed.

F/4- Backround is not in focus


F/22
http://i120.photobucket.com/albums/o178/hobberz01/highapeture1.jpg


F/4
http://i120.photobucket.com/albums/o178/hobberz01/smallapeture2.jpg


Great Exercise:th3:

[bigdazzler]

spot on Hobz .. you can see how shallow the DOF is at f4 .. even the rear of the tap is out of focus. If you stop down another 1/3rd or 2/3rd's of a stop to 4.5 or 5 , you should get the entire tap in focus and the wall will remain burred.

[anne-1303]

Hi Rick, yes I have gained a great understanding of how aperature affects the depth of focus now - something I never understood before!! I have been practicing some more this afternoon, and have no problems with things close up but am having a little trouble getting the background blurred of things abit further away??? Why is this???? Not sure what I am doing wrong here. I tried to take a couple photos of my daughter standing outside, but couldnt' get the background nicely blurred behind her? :confused013

[ricktas]

As you get further away from your subject, the DOF increases, so to get the background blurred you need to ensure your daughter is further away from the background.

[Becstarr]

I just tried to upload some pics but was unable to do so , I just went into reply to thread and then pressed the paperclip to add attachments where did I go wrong

[ricktas]

how big are are your files Becc, they have to be under 1024 pixels on the longest side and under 200KB?

[Becstarr]

Let's try again,

[Robjess]

chelle - yep thats it, the head is the same distance from the camera so its all focused. The tail is further back from the camera, so its not in focus.

[Robjess]

Good examples Bacstarr

[J.davis]

Two Macro shots I have taken today that realy show 'Depth of field' - Comments?
F5 @1/125 90mm
http://img297.imageshack.us/img297/1027/img0027edited1px2.jpg
F57 @1.3 90mm
http://img297.imageshack.us/img297/3626/img0028edited1et8.jpg

[ricktas]

So John, what did you learn about aperture? and when would you use each in a real life situation?

[J.davis]

I cant hold still long enough to take a photo in macro longer than f22 allows.:D

[MrJorge]

I cant hold still long enough to take a photo in macro longer than f22 allows.:D

Lol!! :th3:

[Paper_Mache_Man]

Ok Rick I do have one question.

It was said to me a long time ago that the smaller the aperture (higher the f stop) the sharper the image. This is incorrect is it not? I mean, they were basically referring to DOF but calling it sharpness instead.

So what aperture setting is sharpest and what setting will provide a "crisp" image? Does it vary from lens to lens or is there a general rule of thumb shared by most lenses? Can you surmise where the sweet spot may be depending on the lens construction? Or, does the aperture setting bear no relationship to the final image sharpness.

My own take on it was that somewhere around f12 should be the best as it's the midpoint for a lot of lenses and so shouldn't represent a compromise of any sorts.

What are your thoughts on this?

[Kym]

Ok Rick I do have one question.

It was said to me a long time ago that the smaller the aperture (higher the f stop) the sharper the image. This is incorrect is it not? I mean, they were basically referring to DOF but calling it sharpness instead.

So what aperture setting is sharpest and what setting will provide a "crisp" image? Does it vary from lens to lens or is there a general rule of thumb shared by most lenses? Can you surmise where the sweet spot may be depending on the lens construction? Or, does the aperture setting bear no relationship to the final image sharpness.

My own take on it was that somewhere around f12 should be the best as it's the midpoint for a lot of lenses and so shouldn't represent a compromise of any sorts.

What are your thoughts on this?

Sharpness and DoF are not the same.

Lenses have a sweet spot (re: sharpness) that is usually around f/8 to f/16 and somewhere in the middle to 2/3 of their zoom range if a zoom lens. In part this has to do with a technical issue called the Circle of Confusion (CoC) - which is a fancy way of saying what the human eye can discern at a set distance. CoC is important in lens design.

High f/stops also have an issue with another technical term - limit of diffraction. And this relates directly to the pixel density of the sensor. This is why very high f/stops are often not as sharp as lower f/stops.

Google "Circle of Confusion" and "limit of diffraction" for the gory technical details.

Ok, what does this mean?

CoC defines what the DoF is. Technically only one distance is truly in focus. The DoF is the range of distance to which the human eye cannot discern out of focus (OOF).

The sharpest part of the image is the items at (or practically very close) to the focal distance (the distance where things are 'exactly' in focus).

Hope this helps - it is a bit beyond the scope of NTP.

Edit: Other factors affecting sharpness include : lens quality, focus accuracy and pixel density.l

[MrJorge]

Ultimately it depends on the lens. Most lenses have a "sweet" spot at where they are "sharpest".

But they're not talking about DOF here they are talking about how sharp the detail (that is within the DOF) captured is @ that particular aperture.

General rule of thumb I've seen is a lens is never at its sharpest when @ wide open (smallest f number). Generally if you step down one stop (one stop bigger f number so 2.8->4.0, 4.0->5.6 etc) it will be sharper than wide open.

But where it is "sharpest" will depend on the lens. A lot of the kit lenses are probably best about f8-f11 or so from what I've seen/heard. But better quality lenses are better generally.

Read up on reviews on your lenses at sites like dpreview.com and see if they have any test results you can get a feel for and then go and play yourself and see if you can find it if you're interested.

[jeelan]

hi guys..

just thouht i'd join in the challenges and learn as well..

here's my two pics..

both were taken on a 50mm f1.8D lens

This one's at at f1.8

http://i12.photobucket.com/albums/a227/jeelanamin/Photography%20Course/_DSC0981.jpg

This one's at f22

http://i12.photobucket.com/albums/a227/jeelanamin/Photography%20Course/_DSC0982.jpg

i took these at 0.5m distance from the camera, i'll try and take another couple of something involving larger distances at the local park or similar...

cheers
Jeelan

[ricktas]

So Jeelan, what did that teach you about aperture, that will help out in future with your photography

[jeelan]

hey rick..

the smaller aperture (higher f no.) gives you a greater depth of field vs a larger aperture (lower f no.) which gives you a shallower depth of field...

interestingly, the depth of field itself increases quite a bit when i'm standing further away from my subject....

in the above pics, i was only about 0.5m away from the pins and they were only about 20cm apart from each other..

i've just taken another two pics with greater distances and the changes to depth of field are a lot more ...."subtle" than this....

is there a mathametical relationship between distance from subject to DOF? meaning can you calculate it?

cheers
Jeelan

[ricktas]

Yeah there is, do a google on Depth of Field calculator, the further the subject is away from the lens, the greater the DOF.

So at say using your lens (50 mm) at f1.8

at a distance of 1 metre your depth of field is from 0.99m - 1.01m
at a distance of 5 metres your depth of field is from 4.66m - 5.39m

So even though nothing changed except the distance to subject, the depth of field (area in focus) increased from 2cm at 1 metre to over 60 centimetres at 5 metres.

[happy.grl]

I had a chance to take some shots on the weekend and thought that I would also post my results.

The first shot which was taken at f/8 and 1/50

http://farm4.static.flickr.com/3457/3387875211_4795a8ef70_m.jpg

The second shot which was taken at f/4 and 1/200

http://farm4.static.flickr.com/3423/3387875853_cbd0b82598_m.jpg

The only thing that I have edited with the shots is to crop them so they are basically the same shot with different settings. Both shots were taken using the AV mode on my camera

What did I learn.... I've read a lot about using aperture to blur the backgrounds to make the subject stand out - in the small space that we had the effect was quite subtle. I'm guessing that that is because my aperture has a max (or is that min) of f/8 and the background was not far enough away? I've learned that using DOF to affect foreground can be very effective as well - to me the first photo is really boring, like a shot that went wrong (just composition - ignoring the fact that the cat is not looking at the camera). The second shot interests me a lot more - it kind of feels like I'm observing some action and my attention is not drawn away from the cat

I've also learned that trying to take photos of cats can be really hard when they are not asleep, especially when they decide to come sniff the strange black thing that some crazy girl keeps pointing at them.

Wow. I really didn't mean for this post to be so long :o

[MrJorge]

Great stuff HG, looks like you've learnt a few things and had a play which is fantastic. The differences are subtle in your shots due to the relatively small difference between f4 & f8 but as you say even that can help concentrate interest a bit more and not be distracted by foreground or background elements.

May I ask what you used to shoot these with?

[happy.grl]

Thanks MrJorge
I used a Canon Powershot sx100 is - which is basically a point and shoot, but with optional manual controls.

[MrJorge]

I bought my fiancee the sx110IS last year. Great little camera. And as you say plenty of manual controls (why I bought it) to help you learn. Good luck with it and look forward to seeing how you go with the other challenges and learnings.

[Kym]

Thanks MrJorge
I used a Canon Powershot sx100 is - which is basically a point and shoot, but with optional manual controls.

If you have manual control a P&S will do what 80% of people do with a DSLR. So well done!!

[stylo]

Rick, can I ask a question re. the DOF Depth of Field preview button ?

I think it somehow relates to this thread.

Have googled it before but don't quite get the gist of it.

[ricktas]

The DOF preview button is an interesting one

The best way to understand its effect is to do the following:

- Find a subject like a rose or flower.
- Set your aperture to the largest (smallest f number)
- Focus on your subject and press the DOF preview button
- Change the aperture to the smallest (largest f number)
- Focus on your subject and press the DOF preview button

When you have the DOF preview button depressed, look around your viewfinder, not just at your rose or flower. If you swap between largest and smallest aperture a few times while you try this, you will see the difference and gain an understanding of how it work.

Initially it just looks like it makes the whole scene darker, but that is not true, and by doing the above experiment you will gain an insight into how it works.

[stylo]

Amazing.

Your explanation and another google search and I found my answer. Like you said - look past the "darkening" of the picture and the smaller the aperture, the clearer the pictures are.

Thanks.

[Hamish McHaggis]

What a great site Rick, I'm looking forward to learning heaps.
Here is my go at this challenge; first shot is at f/29, second is at f/4.5. Depth of field is obviously less at f/4.5.
http://lh4.ggpht.com/_HqqQen20ALE/SfrCQM31PsI/AAAAAAAAABY/Vf1UEKXoKng/f29.jpg
http://lh5.ggpht.com/_HqqQen20ALE/SfrCP1p7dJI/AAAAAAAAABQ/0mV8ASLx0fk/f4.5.jpg
cheers

[Kym]

Good work Colin!
Keep this in mind next time you do a portrait / candid to kill the background (and for people focus on the eyes, not the nose)

[Hamish McHaggis]

Thanks Kym, will keep that in mind!
My two pics seem to have disappeared....can still see them on Picassa though...odd...

[Kym]

Thanks Kym, will keep that in mind!
My two pics seem to have disappeared....can still see them on Picassa though...odd...

I can see them.

[J.davis]

I cant see them either?:confused013

[Hamish McHaggis]

Yeah I still can't see them - I'll try again from a different hosting site:
f/29:
http://i43.tinypic.com/51bt5.jpg
and f/4.5:
http://i44.tinypic.com/64fhio.jpg
cheers

[bee]

In Av mode, to gain more DOF (ie: larger f number) it will set itself to longer shutter speed.
For outdoor shoot with no tripod, I tend to get shaky pictures due to the long shutter speed, either from my hand not steady or the person move.
Are there any ways or tips to improve this ?

Thanks.

[Kym]

In Av mode, to gain more DOF (ie: larger f number) it will set itself to longer shutter speed.
For outdoor shoot with no tripod, I tend to get shaky pictures due to the long shutter speed, either from my hand not steady or the person move.
Are there any ways or tips to improve this ?

Thanks.

In a word - yes. A deeper DoF (Av) will mean a slower shutter thus more prone to camera shake.

Subject movement can only be 'frozen' by faster shutter speed. You can improve shutter speed by increasing ISO.

Use the Camera/Lens SR, IS, VR (depending on brand); improve your stance; brace; etc.
Read this: http://www.ausphotography.net.au/forum/showthread.php?t=24043

[Ang]

OK, now that I feel like I have some direction, I'm game enough to post photos (in the beginner section anyway!) A huge thanks to Rick & Kym, the way these threads (in NTP) are set up are a godsend to someone like me who had no idea where to start!

So, my first go at aperture shots, didn't exactly work as I understood it would from my reading:

1. f/4, shutter speed 1/20
http://i111.photobucket.com/albums/n148/Essabel/Ang%20practice/011.jpg

2. f/25, shutter speed 2 sec
http://i111.photobucket.com/albums/n148/Essabel/Ang%20practice/012.jpg

I noticed that the shutter speed was longer & therefore the photo (2) is lighter, from having let more light in. (Inside at night.) However, the writing on the bottle in photo 2 is blurrier, even though the camera was on a tripod. I thought this would have been clearer, as the door knob in the mirror's reflection is??? Is i something to do with over-exposure? (haven't gotten to that tutorial yet.)

This is a much better example, the next day outside:

3. f/4, shutter speed 1/125
http://i111.photobucket.com/albums/n148/Essabel/Ang%20practice/006.jpg

4. f/25, shutter speed 1/13
http://i111.photobucket.com/albums/n148/Essabel/Ang%20practice/005.jpg

This is what I expected. While only the front left-hand leaves are in focus in photo 3, all the leaves are in focus, as well as the background in photo 4. The shutter speeds in both photos are much faster than inside the night before, having a lot of natural light. No tripod for this one.

Any comments or tips for me? Thanks in advance! :)
Ang

[ricktas]

Good work Ang, in your first ones it looks like a movement issue, even though you used your tripod. This can be caused by many things, the most common is the movement created by pushing the shutter button. When you push your shutter button, gently squeeze it, rather than press it.

[MrJorge]

When you push your shutter button, gently squeeze it, rather than press it.

Or use a remote shutter release cable... or if you want the simple, cheap option put the timer on so you press the shutter and there is a 2 sec delay before it opens the shutter. This means it won't be movement caused by you pressing the shutter button.

[sketty]

As I was doing these in the evening I also had some issues with noise and blur, as the lighting was a bit dim the shutter speed was already fairly slow, and the iso was bumped to compensate as well.

Ended up locking in the ISO at 1000 to keep it constant and sat the camera on the table to reduce movement problems.

I tried quite a range of these at different focal lengths to see the difference between the two lenses I've got. Due to the lack of decent light most of them came out underexposed so these ones are the best examples.

Observations:
1. As aperture is decreased the exposure time is increased to compensate for the reduction in light.
2. As aperture decreases the DOF increases.
3. If you don't have adequate light and you're on auto-ISO the camera will probably also increase the ISO = more noise.
4. Increasing the focal length decreases the DOF, in the f/22 shot the figures are all in focus (though the rear one is a bit soft) but the background is still out of focus, though less so than in the f/11 and f/5.6 shots. These figures were only a couple of cm apart, so the DOF at 150mm is quite a narrow range - maybe 5cm (the Oly's a 4/3s sensor so 150mm is a 300mm full frame equivalent).
5. Once you know what you're doing you can use a combination of aperture and focal length to achieve the specific DOF look you are after.

A. f/5.6 1/13
http://farm4.static.flickr.com/3590/3504397732_18e4335c9c.jpg

B. f/11 0.3
http://farm4.static.flickr.com/3386/3503585195_3dcc0bb85b.jpg

C. f/22 1.3
http://farm4.static.flickr.com/3356/3503585727_de8355e990.jpg

Cheers,
Sketty

[ricktas]

Good work Sketty. You have sumarised it well, and hopefully it will let you get more creative shots in future

[Inspired]

okay i'm confused...must be doing something wrong - so any suggestions much appreciated.
(will post some examples once i uplaod to the pc). but thought i would ask why i'm thinking about it.
Alright i tried this quite a few time - got it working when i shot flowers/plants, at 2.8 background was quite blurred then at 22 clear. But when i tried it on different things i just couldn't get it to work - i did everything the same way but could not get a noticeable DOF even using 2.8, tried using kids blocks lined up, tehn tried focusing just on the toy lawn mower in the background and HEAPS of other things, but when looking through the shots between 2.8 and 22, there isn't really any difference in DOF, why can i get it to work on plants but nothing else? I'm completely baffeled by what i'm doing wrong...

[ricktas]

Inspired, the further your subject is from the lens the less the effect is noticable. So a flower shot is close to the lens and you see the effect, but if you take a photo of a person up against a wall from 10 metres away, the depth of field is greater.

for example

So say a 50mm lens set to f1.8 and your flower is half a metre from the lens, your depth of field (depth front to back in focus) is from 49centimetres - 51 centimetres, but move your flower to 5 metres away and the depth of field is from 4.51 metres - 5.61 metres. So up close our DOF is 2cm's, but at 5 metres it is over 1 metre

So the further your subject is from your lens the greater the depth of field at the same aperture, so you have to ensure your background is even further away.

[AmPhot]

I've decided I need to get back to basics and refresh my memory so I can build on re-learning what I should know, so I'm going to go through all the NTP challenges. So here's my first project :

First at F4.8 :
http://img.photobucket.com/albums/v227/crouchy/CH02-ApDOF01.jpg

and then at F22 :
http://img.photobucket.com/albums/v227/crouchy/CH02-ApDOF02.jpg

The smaller aperture gives you a sharper background, but does slow down the shutter speed so a tripod was necessary to achieve the second shot. :)

[Humps n Bumps]

First off, I have to say THANK YOU! This is fantastic.

I have played with cameras (film and P&S) for years, and only now have I learned that the aperture can be used for so much more. I have always just used it for correct exposure, and that's about it. I have had so much fun learning how to play with the subject. I've learned that by using this function correctly, you can make or break the shot, turn the ordinary into the extraordinary.

Oh, and I've also learned that my husband is NOT good subject matter when practicing. :laughing1: I think I'll stick to the inanimate objects for now.

Okay, here's my efforts for tonight, all shots were with a flash. I'll practice in the sun when we get some. :D

f4.5
http://i239.photobucket.com/albums/ff112/TheGrumpyGroup/photography%20practice/DSC_0021.jpg

f22.0
http://i239.photobucket.com/albums/ff112/TheGrumpyGroup/photography%20practice/DSC_0022.jpg

This was trying the different focus points. ( Is that the right term?)

http://i239.photobucket.com/albums/ff112/TheGrumpyGroup/photography%20practice/DSC_0036.jpg
http://i239.photobucket.com/albums/ff112/TheGrumpyGroup/photography%20practice/DSC_0037.jpg
http://i239.photobucket.com/albums/ff112/TheGrumpyGroup/photography%20practice/DSC_0038.jpg

[ricktas]

Great work guys

and Humps n Bumps, your comment about your husband not being good subject matter cracked me up when I looked at your skull shots. Me was thinking I don't blame him if you take this long...LOL

Well done with the aperture challenge and an understanding of how you can creatively change the scene you are capturing by selecting a different and suitable depth of field.

[Humps n Bumps]

and Humps n Bumps, your comment about your husband not being good subject matter cracked me up when I looked at your skull shots. Me was thinking I don't blame him if you take this long...LOL

:laughing1: :laughing1: hahahahaha.. now that is funny.

Thank you. This thread has been an awesome learning tool. I'm one of those people that learn more and quicker with practical and visual lessons.

[Inspired]

Okay i think i get it now. the closer the lens is to the subject the easier it is to create DOF. The further away the subject is the further away your background needs to be to get a greater DOF??
Once i realised this i stop getting annoyed at myself for "doing something wrong" it wasn't that i was doing it wrong just didn't understand how it worked and expected something that wasn't possible.

2.8
http://farm4.static.flickr.com/3330/3566393274_96d34d6d89.jpg

4.5
http://farm4.static.flickr.com/3629/3565557269_7ebe9e7cfb.jpg

22
http://farm4.static.flickr.com/3368/3566350680_a27ce1c2aa.jpg

[Kym]

Okay i think i get it now. the closer the lens is to the subject the easier it is to create DOF. The further away the subject is the further away your background needs to be to get a greater DOF??
Once i realised this i stop getting annoyed at myself for "doing something wrong" it wasn't that i was doing it wrong just didn't understand how it worked and expected something that wasn't possible.

Just to clarify... You don't create DoF - it is always there. It is a question of how much.
The closer you are to the subject the shallower the DoF.
The extreme case being Macro photography.

Use this tool... http://www.dofmaster.com/dofjs.html
To experiment with different settings.

[IanB]

I have written this before; hope it's not here; but this is how I got my head around DOF. Start laughing now because by the end you will be anyway

By now you would have learnt that a smaller aperture [f11; f16; f22] setting gives greater DOF; and larger aperture F2.8; f4; f5.6 will give less DOF.

I worked out that if I set aperture to F16 I required a slower shutter speed which "allows more time for more of the scene to get onto the film/sensor" Now that is technically not right; but it's how I got my head around it . .:o

Large aperture requires a faster shutter speed = less DOF [less time for the scene to get into the camera]

Smaller aperture requires a slower shutter speed = more DOF [more for time the scene to get into the camera]

Aperture; depth of field; and those stupid f stop numbers is one the hardest things to sort out in photography. .:angry0:

:)
.

[Kym]

I have written this before;<snip>

We use the Water model to explain it... http://www.ausphotography.net.au/forum/showthread.php?t=24079

Imagine you have a wall with a hole in it and a bucket on the other side. Light is water, Aperture is the size of that hole, shutter speed is how long you push water through it. Only thing is aperture is backwards (inverse) so lower number is more, and higher is less. Its a fraction. So 1/2 is larger than 1/4 which is larger than 1/8.

1. Aperture (Usually Av or A on the camera dial)
Imagine pushing water though for 5 seconds with a medium size hole (f/4). Thats enough to fill the bucket so thats a perfect exposure. Then keeping the time at 5 seconds you shrink the aperture to a smaller hole (f/8). As the hole is smaller not enough water(light) gets through and the bucket doesn't properly fill - thats under exposure (darkness). Then keeping the time at 5 seconds you make a really large hole (f/2). You push the water through, but because it's a lot bigger you get too much water (light) and it overflows - thats over exposure (an over-white picture). Aperture is what controls Depth of Field (see below).

2. Shutter Speed (Usually Tv or S on the camera dial)
Change the hole for this section to a constant (f/4). 5 seconds water is the perfect exposure from above. Imagine only pushing water through for 1 second. Not enough water to fill the bucket so the photo under-exposes. Then push water through for 10 seconds. Too much water, bucket overflows - over-exposure.

[jjnic]

Ok, Here are my aperture shots.

The first at f1.8 focusing on the end of the barrel has just the end of the barrel in focus so shallow DoF. Shutter speed fast as lots of light coming in through the wide open aperture. love the 3D look of this.

Second shot at f5.6, DoF is greater as bit more of the barrel in focus, smaller aperture so shutter speed is slower to let same amount of light in.

Third shot at f22 i focused on the same point but it is blurry. I expected the whole picture to be in focus but with smaller aperture the shutter speed has to be greater so i believe the out of focus issue to be related to movemet of the subject as i used a tripod.

Now for the next challenge :-)

jj

[ricktas]

Good work jjnic. So using what you have learnt in this challenge, you should be able to find other situations where you can apply a certain aperture to make you photo creative.

[Calelli]

I used this to explain DOF to my kids who were curious why some bits were blurry.

35737

35738

[Lucky23]

Here's my effort.

Aperture=f5.6
Shutter Speed=0.3sec
http://i696.photobucket.com/albums/vv323/Lucky2386/Foruploading0005.jpg

Aperture=f36
Shutter Speed=13sec
http://i696.photobucket.com/albums/vv323/Lucky2386/Foruploading0006.jpg

I've been trying to get my head around the whole aperture and depth of field thing for a while, but after doing this little challenge it started make much for sense. I think basically the smaller the f number, the greater the portion of the background will be blurred. Like in my photo with f5.6 only the second fret of the guitar is in focus and the rest is blurred out. Then with the camera at f36 the rest of the frets are in focus.

The f36 one doesn't seem in focus as i don't have a tripod and was balancing my camera on a very unstable pillow :p. That reminds me... the more you increase the f number the longer the shutter stays open.

I'm pretty sure i understand the method... i just think i'm a little fail at explaining it :confused013. Please correct me if i'm wrong.

[MrJorge]

That reminds me... the more you increase the f number the longer the shutter stays open.

I'm pretty sure i understand the method... i just think i'm a little fail at explaining it :confused013. Please correct me if i'm wrong.

Yup you got it :th3:

A higher f number actually means that the lens is closed tighter than a lower f number. Since the lens is closed tighter it allows less light in therefore the shutter speed has to stay open longer to maintain a correct exposure.

[newhart]

http://farm4.static.flickr.com/3404/3645818818_9df7232008_m.jpg
aperture: 5.6
shutter: 1/500

http://farm4.static.flickr.com/3645/3645818800_511a0e4e79_m.jpg
aperture: 36
shutter speed: 1/15

Correct me if I'm wrong: The smaller the number the larger the openning which lets in more light hence a faster shutter speed to compansate the amount of light. My question is does this give the shot a bigger or smaller depth of field and does depth of field relate to the amount of the shot in focus.
I can see how to apply the different apertures ie if you had a group of people that were standing at different distances from the lens and you wanted them all to be in focus then you would choose a higher f/stop (smaller aperture) with slower shutter speed. And use the opposite for say a protrait where you do not require the background to be in focus.

I have always gotten confused with explainations of these concepts.

[ricktas]

Correct me if I'm wrong: The smaller the number the larger the openning which lets in more light hence a faster shutter speed to compansate the amount of light. My question is does this give the shot a bigger or smaller depth of field and does depth of field relate to the amount of the shot in focus.
I can see how to apply the different apertures ie if you had a group of people that were standing at different distances from the lens and you wanted them all to be in focus then you would choose a higher f/stop (smaller aperture) with slower shutter speed. And use the opposite for say a protrait where you do not require the background to be in focus.

I have always gotten confused with explainations of these concepts.

You are right, the smaller the F number the bigger the aperture opening will be, thus more light comes through the lens to hit the sensor, meaning faster shutter speeds can be obtained. The bigger the aperture (smaller number) the smaller the DOF will be.

Be careful shooting at a small aperture (f22) with people standing at different distances to the lens. You will need a reasonably bright day to do that. As you state, the smaller the aperture the slower the shutter speed, if you slow the shutter speed down too much, you will see blur in your subjects cause they moved whilst the shutter was open.

[newhart]

Thank-you Rick, I thought I got the concept. I agree with watching aperture in different situations, am better at practical as apposed to theroy.

[Kym]

Thank-you Rick, I thought I got the concept. I agree with watching aperture in different situations, am better at practical as apposed to theroy.

Best is to do it as you have seen. But these also help (simulators) http://www.ausphotography.net.au/forum/showthread.php?t=24385

[Papillon]

Hi all, my first link. Fingers crossed.

Mod edit... URL links added... the IMG links are not loading for some external reason
f3.5
http://lh5.ggpht.com/_vi9tmvPLFac/SlHl9pQxc9I/AAAAAAAAACg/im1vTU7ITE0/f3.5.JPG
http://lh5.ggpht.com/_vi9tmvPLFac/SlHl9pQxc9I/AAAAAAAAACg/im1vTU7ITE0/f3.5.JPG

f22
http://lh6.ggpht.com/_vi9tmvPLFac/SlHnj0Y9ZxI/AAAAAAAAADM/nYZqMjeBt4s/f22.JPG
http://lh6.ggpht.com/_vi9tmvPLFac/SlHnj0Y9ZxI/AAAAAAAAADM/nYZqMjeBt4s/f22.JPG

This is the label I stuck on the back of my film camera while I was still trying to get the whole aperture/f stop/DOF thing straight in my head. Crude but highly effective, but a bit trickier to do on a somewhat busier digital body.:) Perhaps on your gear bag etc.

http://lh3.ggpht.com/_vi9tmvPLFac/SlHnpgZDQPI/AAAAAAAAADQ/v1Tym-hCcI4/DOF%20label.JPG
http://lh3.ggpht.com/_vi9tmvPLFac/SlHnpgZDQPI/AAAAAAAAADQ/v1Tym-hCcI4/DOF%20label.JPG

Boy oh boy I sure do love digital. Although I had learned much of this stuff some time ago working with film it never really sank in, but now with the instant feedback and zero cost of digital I can fire off as many practice shots as I like and view them while it is still fresh in my mind and truly absorb what is happening.

Thanks Rick and everyone involved in this brilliant learning tool, the NTP thread, despite much web surfing over time I have found nothing to compare with it.:th3: :th3: :th3:
I feel I am beginning on the path to becoming a true photographer instead of just a weekend snapper.

[ricktas]

Well done with your two photos Rob. They show very well the effect of different apertures on the resulting photo. I hope it helps you next time you are out and about, to decide on an aperture to get a creative result.

[draco]

Well, I finally started the NTP "course" here in AP tonight.. was reading the learning plan upto the Experimenting with Aperture and went to this Challenge.. grabbed the camera, my subject and my tripod.. also used two different lenses..

below are shot with the Tamron 17-50 @ 46mm

@f/2.8, 1/2 sec

http://farm3.static.flickr.com/2641/3693456807_239bc03ca0_o.jpg

@f/10, 6.0 sec

http://farm3.static.flickr.com/2584/3693458459_49203aea9d_o.jpg




and below pics are shot with a Tamron 70 -300mm @ 100mm


@f/4.0, 1 sec

http://farm4.static.flickr.com/3552/3694265898_54895df10a_o.jpg

@f/10, 6 sec

http://farm4.static.flickr.com/3614/3693462239_3eee5bca5f_o.jpg



maybe i will experiment more and try to understand more about DoF :D

[ricktas]

Good work Draco. Understanding how aperture settings work and how it affects not only the DOF, but also the shutter speed is important. Shutter speed, Aperture and ISO are all inter-twined and learning to use all three together is how you move from Auto mode to Manual mode.

[Carly]

Thanks Rick, here's my try at it! Definitely beginning to understand how to use my camera for more effects now! i'm guessing the "pre-defined" modes on the camera also have their own AV settings and this is how i get nice effects from those for dif. purpose? (or part of the picture anyways ;)

also tried out how photos using different focus points on the camera (not posted), good fun to play with as well and greatly useful as well!

so.. (correct me if i get muddled!)

Smaller DOF:
lower F number = higher aperture = more light into the camera = faster shutter speed = less time for camera to gather all the light and capture it = out of focus area more blurry - and therefore can see less detail in this area

Larger DOF:
higher F number = lower aperture = less light into camera = = slower shutter speed = more time for camera to gather all the light and capture it = out of focus area less blurry - and therefore can see more detail in this area

so the f value "basically" defines the amount of light allowed to go into the camera lens?

shutter speeds are slower when the object is further away? would that be correct?

Closer Object: - notice more blur with the out of focus areas
ISO A-1600 55mm f/22 1/10sec
http://i87.photobucket.com/albums/k138/insanedoh/IMG_2103_Medium.jpg
ISO A-800 55mm f/5.6 1/100sec
http://i87.photobucket.com/albums/k138/insanedoh/IMG_2104_Medium.jpg

Further away object: - notice less blur with the out of focus areas:D
ISO A-200 55mm f/22 1/100sec
http://i87.photobucket.com/albums/k138/insanedoh/IMG_2113_Medium.jpg
ISO A-100 55mm f/5.6 1/800sec
http://i87.photobucket.com/albums/k138/insanedoh/IMG_2116_Medium.jpg

Pulled the image settings out of lightroom so assume they correct - just learning how to use it.

thanks again :)

[ricktas]

Good work Carly. You are correct that the programmed auto modes are just programmed to set these automatically. Learning how to do it manually though is the key to creative photography.

[Carly]

Thanks Rick! Manual is exactly what I want to learn, this forum is great :)

[Kym]

Thanks Rick! Manual is exactly what I want to learn, this forum is great :)

I think we need to differentiate between
a) Full Auto - the camera software does everything
b) Semi-Auto (or Semi-Manual) - Aperture Priority (Av or A) , Shutter Priority (Tv or S) where you manually set one thing and the camera adjusts the rest
c) Manual (or full Manual) - where you set everything

We know that most people use Av and then M when they need to. (Based on a site poll)
http://www.ausphotography.net.au/forum/showthread.php?t=13627

Don't go rushing off to M unless you really need to.

Also think about using Exposure Compensation (Ev) with Av or Tv.
http://www.ausphotography.net.au/forum/showthread.php?t=33981

[draco]

where does the P (Program AE ?) fall into? Full-auto or semi-auto? this is what I usually use :D

[Kym]

where does the P (Program AE ?) fall into? Full-auto or semi-auto? this is what I usually use :D

Effectively its Auto (at least in my case).

Don't make it a law - just a guideline to help thinking.

If you take control of one or more aspects of the exposure then its no longer fully auto, but nor fully manual.
I usually take control of 2/3 (Av and ISO) and let the camera sort the shutter (Tv).
I also make good use of the Ev and metering to fine tune.

[draco]

yeah, that's why I use the the P-mode, because I got control of everything (except shutter speed and aperture, since the camera still has a better judgement than me on these values).. but I guess I better start using Av more... :D

[Carly]

thanks cypheroz, yerp what i mean by manual, is anything that means i'm changing the settings away from a standard "point & shoot" auto everything mentality. (the more i learn about how to change the different settings and can use them effectively the better!) i think it will take awwwwwwwwwwwwhile though! For the moment, the "semi-manual" is more than enough :)

[Kym]

thanks cypheroz, yerp what i mean by manual, is anything that means i'm changing the settings away from a standard "point & shoot" auto everything mentality. (the more i learn about how to change the different settings and can use them effectively the better!) i think it will take awwwwwwwwwwwwhile though! For the moment, the "semi-manual" is more than enough :)

The NTP learning plan progression is as follows ...

Full auto (with fixed ISO of 100 or 200) while learning to hold your camera and compose shots
Aperture Priority (fixed ISO) while learning DoF
Shutter Priority (fixed ISO) while learning movement control
Changing ISO (100 thru 1600) using mainly Av while learning about sensitivity and noise
Full manual control of the exposure triangle (ISO, Aperture, Shutter)

The plan is structured to build knowledge and experience in bite size pieces - those who suggest just go fully manual without working through the above steps are saying in effect don't learn and understand the basics in discrete parts. Which is why we stomp on that sillyness.

Bottom line - it takes a while for people to absorb the theory and then apply it to their photography. We try to make it easy and sensible.

[brownie79]

OK, here are my shots. Not very exciting subject matter, but it does the job :p
f/5.6 shutter 1/10 iso 800
http://danielathome.com/images/DSC00020.jpg
f/32 shutter 4 iso 800
http://danielathome.com/images/DSC00021.jpg

The larger aperture allows more light in, therefore requiring shorter shutter opening. Also give a greater depth of field.

[AusBloke]

Still getting my head around all this but, I can see what everyone is talking about even if I don't fully understand it yet.


http://i245.photobucket.com/albums/gg44/BeerOps/AusPhotography/IMG_0711.jpg

http://i245.photobucket.com/albums/gg44/BeerOps/AusPhotography/IMG_0712.jpg

[ricktas]

So Ausbloke, what do you see as the difference in your photos created using the different apertures?

[AusBloke]

Well the obvious part I can see is the blurred background in pic1 and the sharp foreground. In pic2 I see the whole image is basically sharp focused.

[ricktas]

Well the obvious part I can see is the blurred background in pic1 and the sharp foreground. In pic2 I see the whole image is basically sharp focused.

Yep, so now if you wanted to apply this to a portrait, you would know which aperture to select to get your subject in focus and the background nicely blurred. Using aperture settings creatively lets you chose how your photo is going to appear.

[AusBloke]

Thanks mate, starting to get the gist of it now.

[Gemini2261]

Pic #1 F5.6
Pic #2 F29

# 2 is slightly brighter

[chrisbevan4]

I cropped the details of two images and put them into one file, and have also drawn a Yellow arrow where the different between the different apertures
is very obvious to me.

So a small aperture can be used to isolate a area and reduce/blur a background, and a large aperture show greater detail and include background details.

Looking at them now maybe I should of set the same shutter speed as well? :o

Would shutter speed have much impact ? I'll do the Shutter Speed challenge as well as that may give the answer

44918

[whizzbang]

Okay, So I have finally got around to doing this challenge. I have read and reread it!
I did the challenge twice as looking at the display screen while taking the pics, I couldn't really see the difference. Though, when uploaded to the big scree on my computer, you can really see what it happening.
1) f4.5 1/30
2) f29 1.3sec
3) f4 1/30 sec
4) f22 1/5 sec

So, for 1 most of the flowers/leaves were blured except for the main lily and gerbra.
2, all steams, leaves flowers are pretty much in focus.

For 3, Only really the closest corner of the book was in focus, and for 4 all of the book was in focus, and even the end of the table was in focus, which suprised me.

For the second shots of both series, I had to be extra careful to hold the camera still, as my first attempts were coming out fuzzy from 'camera shake'' (or just my unsteady hands lol)

Thus.... If I wanted to take a pic of something to highlight it, say a ring on someones hand for eg, I would use the smallest apperture, and it would bring attention to the ring and not the hand... Another example would be portraits- emphasising the person and not the background.

However, if I wanted to take a pic of someone with a nice scenery in the back ground, I would use the larger apperture.

If I had remembered this the other day when I was on holidays I would be laughing now!!!

I did also notice that changing the focal point of my camera changed the minumin apperture settings.


ALso, can someone else help me out here. In pics 2 and 4, on the top, there is marks in the pics, however they are not in pics 1 and 3. Is there some other part of the camera that needs to be cleaned?

Thanks for reading if you have got this far :food04:

[kiwi]

hmm, that looks unusual, not like sensor dust to me, it looks at though perhaps there lens is very dirty, either front, but more likely at the back

[whizzbang]

hmm, that looks unusual, not like sensor dust to me, it looks at though perhaps there lens is very dirty, either front, but more likely at the back

But wouldnt it be on all 4 pics, since I didnt cahnge the focal lengths between pics 1/2 (30mm) to 3/4 (25mm). All I changed was the app settings. :(

[kiwi]

not necessarily, the smaller the apperure the more obvious the issue

[ricktas]

As kiwi says, sensor dust will often not be visible at f3.5 etc, but as you get towards f22 etc, then it will become very evident.

You also comment about smaller aperture and largest aperture, but you have the idea the wrong way round. F22 is the smallest aperture and F3.5 is the larger. The smaller the f number the larger the actual aperture in your lens. Aperture being the opening in the lens that light can come through.

[linden]

Thanks a lot for this info guys.

I have just read through this thread and have leant a lot!

Its very useful to know that when the lens is closer to the subject, the DOF is shallower, so there is less margin for error with the focus, and the background will be blurred much sooner..

[whizzbang]

Thanks Rick,
Ok, will try again...
The smaller the aperture,, the larger the f number, the more that will be in focus/ greater depth of field- becasue there is more light being let in.

The larger the aperture, the smaller the f number, less in focus/ smaller the depth of field- because there is less light being let in?

[ricktas]

Thanks Rick,
Ok, will try again...
The smaller the aperture,, the larger the f number, the more that will be in focus/ greater depth of field- becasue there is more light being let in.

The larger the aperture, the smaller the f number, less in focus/ smaller the depth of field- because there is less light being let in?

sort of. You have the reasoning partly right

The smaller the aperture (larger number), the longer the shutter speed will be cause the smaller aperture lets less light in, and yes you will end up with more in focus, front to back.

The larger the aperture (smaller number) the faster the shutter speed will be cause the larger aperture lets more light in, and then your depth of field - DOF ( front to back focus distance) will be narrow

[SnowA]

It took me a while to get my head around the f/number and the size of the hole (aperture) when I was first grappling with it.

In the end, what helped was to think of the f/number as a fraction where f=1, ie. f/22 = 1/22 which is smaller than f/4 (1/4). Depending on how you think it might help.

[Boo53]

I found some time to get out in the garden and take a few photos today.

My gear consists of a Sony A300 with dual kit lenses & a sony 50mm f1.8

1st shot is 50mm lens 2sec @ f22
2nd shot is 50mm lens 1/80 @ f1.8
3rd shot is 50mm lens also 1/80 @ f1.8 but with a much closer focal distance which has tightened up the depth of focus significantly
The final shot was take with 130mm focal length + 32mm extension tube and a bit of flash through a home made diffuser (plastic cup).

[kathfern]

Ok here is my attempt.
I am hoping I have the image posting requirements right as well as the exercise!

Picture 1: F4 - Blurry Background
Picture 2: F22 - Background in Focus

I noticed that when I was taking the picture at F22 (camera was resting on the table) that it took a long time to actually take the picture. If I was hand holding it, I imagine it would have come out all blurry from camera shake?

http://i445.photobucket.com/albums/qq175/kathfern/DOF1.jpg

http://i445.photobucket.com/albums/qq175/kathfern/DOF2.jpg

[barrythelizard]

Hi. This thread is such a huge help to understand this stuff. I ended up taking two sets of photos as I didn't feel I was quite close enough to the subject in the first set:

1. f/3.5
2. f/22
3. f/3.5
4. f/22

I noticed immediately that 1) I will need a tripod if I want to have everything in focus in a picture, and 2) that a cat does not make for a good aperture experiment. I started off with next door's cat as my subject, which was fine for f/3.5, but she had run off before f/22 has done it's thing. My next set were also abandoned as the subject was not at ground level and I ended up with absolutely nothing in focus at f22.

So, the shutter speed is much slower at the smaller f22 (it's tricky that bit) aperture setting and faster at the higher f3.4 one. The background retains more detail the smaller the aperture, while the bigger the aperture and faster the shutter speed only the subject of the photo is in focus.

I really liked having that control so I'm going to be keeping the camera set on 'A' mode from now on :)

1.
http://barrythelizard.jalbum.net/Clair%27s%20Pics/slides/set1%20f3.5.jpg

2.
http://barrythelizard.jalbum.net/Clair%27s%20Pics/slides/set1%20f22.jpg

3.
http://barrythelizard.jalbum.net/Clair%27s%20Pics/slides/set2%20f3.5.jpg

4.
http://barrythelizard.jalbum.net/Clair%27s%20Pics/slides/set2%20f22.jpg

[ricktas]

Good work guys. This is exactly what these challenges are about, getting you to use and understand a camera setting and work out how it affects the end result. Learning one camera feature at a time will slowly let you put it all together and allow YOU to determine how your photo will come out, by selecting the settings needed to create the result you want.

[bobsie]

Hi all,

Here is my first post (with samples), using different Aperture Settings. I became more aware of the relationships between available light and the aperture settings.

http://i1040.photobucket.com/albums/b409/tarantula4/dof5exampleforcc.jpg
http://i1040.photobucket.com/albums/b409/tarantula4/dof4exampleforcc.jpg
http://i1040.photobucket.com/albums/b409/tarantula4/dof3exampleforcc.jpg
http://i1040.photobucket.com/albums/b409/tarantula4/dof2exampleforcc.jpg
http://i1040.photobucket.com/albums/b409/tarantula4/dof1f35forcc.jpg

My focussing technique needs some work.

CC: always welcome!

[ricktas]

I am pleased that members are finding this challenge worthwhile and I hope that slowly your understanding of the aperture settings (F stops) becomes clearer, eventually allowing you to choose exactly how your photos are exposed to suit your creative endeavours.

[tanz]

This is a great challenge. I was having a hard time a couple of weeks ago get my background to be as blurry as I wanted and then I read something which made me change my lens. I have taken some more today, the first two were taken with the 18-55 lens and the second two were taken with the 55-250 lens. All were taken in the Av mode with the ISO set to select automatically. The first was taken with the aperture of f/32, the second f/5, the third f/22 and the fourth f/4. So the thing I have learnt out of this is that the longer lens will also make a difference.

http://farm2.static.flickr.com/1382/4729434890_a733c7bbf1_b.jpg

http://farm2.static.flickr.com/1310/4729433538_2e6495ff3f_b.jpg

http://farm2.static.flickr.com/1370/4729432508_6a2b0619f4_b.jpg

http://farm2.static.flickr.com/1405/4729431290_548e9ca031_b.jpg


This is the first time I have attached photo's, so hope they have worked alright. :)

[Boomshanka]

I initially had trouble getting the smaller aperture pic to be bright enough. I cheated and used the BULB setting for shutter in 'M' instead of 'Av' to make it 60 seconds with a remote button thing that I'd borrowed, but it still didn't help much. Later realized I had the ISO set to 100 not auto. Tried it again in Av on a different subject and got a better result with the auto ISO.

f4.5
shutter 6"
Mainly just the dodgy knob in focus
http://i96.photobucket.com/albums/l168/b00mshanka/Amp_1.jpg

f22
shutter 60" using BULB and remote button thing
A lot more in focus, but too dark and underexposed
http://i96.photobucket.com/albums/l168/b00mshanka/Amp_2.jpg

f4.5
shutter 5"
Very small depth of field
http://i96.photobucket.com/albums/l168/b00mshanka/piano_1.jpg

f18
shutter 10"
Can now see most of the keyboard
http://i96.photobucket.com/albums/l168/b00mshanka/piano_2.jpg


I took this one at the same aperture setting as the first piano one, just using a different focal point a bit closer to the camera. Noticed how much shorter the depth of field is when the focal point is closer to the camera.

f4.5
shutter 5"
Even smaller depth of field than first one
http://i96.photobucket.com/albums/l168/b00mshanka/piano_close_focus.jpg

[ricktas]

well done boomshanka, from this challenge you should have now learned what your aperture dial does and how it affects your photos. Hopefully you can see how you can put his camera feature to use, in future, to create a photo with the right depth of field to focus on your subject and leave the non important elements blurry.

[Alan Weston]

Hi Rick You don't have to carry a laptop to have a DOF chart. There is an iphone app called Dr DOF to do this for you. It's simple to use and gret for calculating depth of field

[ricktas]

Hi Rick You don't have to carry a laptop to have a DOF chart. There is an iphone app called Dr DOF to do this for you. It's simple to use and gret for calculating depth of field

I use the iPhone app Photocalc. But rarely do I need to use one these days. As your photography progresses you can estimate it fairly well anyway. All part of the learning curve and knowledge that we all eventually store in our heads.

[RebelT2]

my camera would only let me do f5.6 and f25 so here are my two.

[alison]

Here is my attempt at this - I am hoping the photos will upload properly, it's the first time I've done this!
This first photo was at f5.6 http://farm5.static.flickr.com/4079/4747722347_795f50e026_b.jpg
The second was f11...http://farm5.static.flickr.com/4076/4748366696_917734e8c2_b.jpg
and the third f32. http://farm5.static.flickr.com/4136/4747725187_b5fbff5546_b.jpg
I found that the light did change a bit even while I was taking the photos so I think that probably effected it a bit, but it was still pretty clear to me what a difference changing the aperture did! Great challenge to start off with!