PDA

View Full Version : Lens laws



Journeyman
05-12-2020, 1:18pm
Hello, I am beginning to seem like a serial questioner.

The answers to which lens is most successful for a given camera and subject seems to be almost unlimited.

My question relates to lenses used for bird photography and the ability to gain a sharp focus. My photos shows that the focus can be very sharp, just not focused on the birds.

A 600mm lens on a full frame camera is just that, 600mm. Surrounded by an enormous amount of magnifying lens glass. The quality of the photos is therefore appropriately high and sharp. Does this suggest that a prime lens offers clearer shots than a zoom lens?

A 400mm lens on a Canon crop frame camera is effectively a 640mm lens. With lesser amount of glass the photo is a little less sharp etc.

I have Canon EOS 90D, the best lens I can reach is an EF100-400mm 4.5-5.6 L II. A great lens in any circumstance. However my shots don't come out with the tack sharp focus I would like to achieve. I have attached a couple of photos with complete with exif data. (1 Tamron 18-400 X bird on the wing and 1 Canon 100-400 two birds hanging around).

Would a 70-300 produce a better image? It would be 480mm crop frame size and a 1.4 converter would take it out to 672mm.

The search for a better image and reliable technique goes on.

Thank you for entering the chat, Journeyman


145429145430

ameerat42
05-12-2020, 3:44pm
I had to break up your points to try to address them... Answers are in yellow.



My question relates to lenses used for bird photography and the ability to gain a sharp focus. My photos shows that the focus can be very sharp, just not focused on the birds.

This the foregoing tells me there's either or both of: something is wrong with your focusing technique; and: the lens focus is faulty (like it needs a micro-focus adjustment).
Look online for tests of "back-focusing" and "front-focusing", and how to fix them.


A 600mm lens on a full frame camera is just that, 600mm. Surrounded by an enormous amount of magnifying lens glass. The quality of the photos is therefore appropriately high and sharp. Does this suggest that a prime lens offers clearer shots than a zoom lens?

A 400mm lens on a Canon crop frame camera is effectively a 640mm lens. With lesser amount of glass the photo is a little less sharp etc.

I have Canon EOS 90D, the best lens I can reach is an EF100-400mm 4.5-5.6 L II. A great lens in any circumstance. However my shots don't come out with the tack sharp focus I would like to achieve. I have attached a couple of photos with complete with exif data. (1 Tamron 18-400 X bird on the wing and 1 Canon 100-400 two birds hanging around).

The cited text that is in bold I simply do not understand :o So, to try to address the rest:
Rather than say "effectively" above, say instead that "it's an equivalent angle of view to", because the resultant difference in image sizes make it anything
but "effective" in this context.

Again here also read my first reply above. You'll need to sort this problem out. On the question of primes and zooms, one could reasonable expect a prime to
give a higher image quality (IQ) than a zoom simply because of the variability built into the latter. BUT, it also depends on the quality of the lenses. A bad prime
vs a VG zoom, for instance.


Would a 70-300 produce a better image? It would be 480mm crop frame size and a 1.4 converter would take it out to 672mm.

Addressing only the interposing of extra optical elements, be aware that there is a likelihood of image quality (IQ) loss.
Again, forget the numbers.

You will get other replies that may be of more help, but I've just mentioned some basics.

About "FF lenses" and "Crop frame lenses". Using an FF on a crop body certainly does not create any problems for illumination.
About smaller [diameter] lenses reducing IQ: Not necessarily because stopping down a larger diam lens has the same effect.
(I don't know if you actually asked about this, but it's what I understand.)

Of your images, I can't tell what is in focus in the first, and for the second, the sharpest focus seems to be around the log.

About the two lenses you used: 18-400 and 100-400.
The first lens sure has to do a lot of optical gymnastics, and you'd have to wonder how good it is throughout the zoom range.


- - - Updated - - -

PS: Your title, Lens Laws, is mostly just good alliteration. Of course there's Lenz's Law, but it's not about optics :D

arthurking83
05-12-2020, 7:54pm
Like Am already wrote: there are no lens laws.
There are lens general and vague guidlines, such as:

1. the harder it is on the wallet, the spine, the backpack, the family relationships(etc :D) ... the higher the resultant IQ.
2. the more focal length multiplication, the lower the IQ at the long end(and sometimes at the wide end)
3. it used to be that prime lenses were far superior in resultant image quality and sharpness, but modern optics engineering has reduced this discrepancy. (there is a website called LensRental, they do blogs and tech posts that confirm this)
4. the more you try to magnify a lower magnification lens with additional optics(teleconverters) or digital zooming(cropping), expectations are deflated.

A 600mm lens doesn't necessarily equate to more glass in any way.
The magnification of a lens(ie. the focal length) is more about the spacing between one main lens(one of the front optics) and one of the rear lenses in the lens group.

The reason a 600mm lens is so much larger is nothing to do with more glass, it is about the distances to the important glass elements that produce this 600mm focal length.
Zooms just complicate things a lot more.

When you here the term telephoto lens, people assume it just means that it's a long focal lens(ie. 300 or 400 or ... etc)
This is incorrect, but it's kind'a true. Telephoto only really means that the focal length stated(lets say 600mm) requires a distance of 600mm between the primary optic piece in the lens and the focal plane(the sensor or film)
Manufacturers try to decrease this for the purpose of weight and compactness. A telephoto 600mm lens has a distance shorter than 600mm between the main optic and focus plane that produce the focal length.

Note that there is usually a primary optic in a lens, and many that do other optical adjustments like colour correction(chromatic aberrations) and distortion adjustments and stuff like that.

It is true that less glass in the lens equates to (possibly) lower image quality in some way.
The most simplified method to see this could be done at home with a simple magnifying glass.
Your eyes are not quite as acute as a digital sensor, but if you remove the lens, and use a magnifying glass placed at a specific distance where the lens should be, you can easily render an image. It won't be as sharp as a proper lens of that same magnification, but it will be an image.

Suggestion: almost all of these large range super zoom lenses usually work ok at a longish but not terminal focal length setting.
I have no idea about where this will be on the Tammy 18-400, but lets say 350mm or 330mm or something about that range.
It may produce a reasonable sharp image by comparison to 400mm setting.

I think we discussed this previously, where I suggested a new modern 100-400mm lens from Tammy and Siggy may produce quite acceptable sharpness.

The Canon 100-400 is well reknown for it's ability tho.

Any lens beyond 400mm will be very very heavy for someone with some physical limitations. That would almost certainly require some camera/lens support which helps with shooting, but not transportation by foot!

I recollect that Canon has a very high quality Diffractive Optics(DO) 400mm lens that is supposed to be very good quality.

If you want to maintain a Canon centric hardware environment, maybe consider a Canon mirrorless R body, and one of their new 600mm or 800mm telephotos for it.
They seem reasonably cheap, very lightweight(plus the camera combination) only downside is the very small max aperture. f/11, so the camera will require a lot of ISO(really! .. very much maxed out).
As they will be mounted to a mirrorless camera, view through the lens will not be as dim as small aperture lenses used to be through an SLR system .. anything f/8 and smaller produces a very dim viewfinder experience compared to what most folks are used too.
But even tho the view will be respectably bright, it will amost certainly be affected by noise(ISO noise). The viewfinder in a mirrorless is 'gained' or brightened via electrickery in low light, such as a couple of hours before sunset will affect viewfinder.

I didn't mention the Canon R and 600mm or 800mm lens option in your earlier thread, as I assumed you just wanted to stick with the camera bodies you have.

But if funds allow this upgrade path, then Canon R camera of some type and either 600mm f/11 or even the 800mm f/11 will be easy on the body, they appear to produce very high quality images considering the lens type they are(and price) .. recommended.

Journeyman
05-12-2020, 10:01pm
Firstly, thank you for your time.
The heading Lens Laws was a bit tongue in cheek. There are photography unofficial guide lines to what works and what does not. The understanding I have gained from the Aust. forum made me realise I was heading down a doomed mental path. It is not necessarily that more dollars would give more results.

The reason for the 600 mention was that the focal length of 600 can be recreated on a crop frame using a 400 lens. I have always had trouble settling the comparison in my mind. I have seen beautiful pictures of birds with prey (large an grub sized) that are sharp and clear. I have photos of ospreys that are not cropped that fill the shot. Right place right time.

I think the last time I posted about a lens it was related to the use of a 400 type lens and the weight. I am working on a solution (I hope), as mentioned the 600 size lens would involve a lotto win at least.

Therefore I am wanting to stay in the range of most manufacturers 400, the Tamron has served me well. I believe it is about 10 to 15% shorter than advertised. Using an used shooting target, holding the position of target and tripod I was able to compare the magnified result. The measurement was 120mm on lens a. and 100 on the Tamron. An otherwise excellent lens by most measures.

After some reflection I think that my focus problems are due to my less than steady hands. As long as I have had hands they have never been steady. The obvious fix is to become good friends with a monopod at least and a tripod when needed.

Thanks again for the info you both provided, your knowledge and good hearted distribution are very much appreciated. I now know the direction that I need to walk.
Kind regards, Journeyman (Dennis)

ameerat42
06-12-2020, 2:14am
...
The reason for the 600 mention was that the focal length of 600 can be recreated on a crop frame using a 400 lens. I have always had trouble settling the comparison in my mind. I have seen beautiful pictures of birds with prey (large an grub sized) that are sharp and clear. I have photos of ospreys that are not cropped that fill the shot. Right place right time.
...
After some reflection I think that my focus problems are due to my less than steady hands. As long as I have had hands they have never been steady. The obvious fix is to become good friends with a monopod at least and a tripod when needed...

[Call me a pendant, but]
To help get this idea right, viz: equivalent angles of view, think of "similar triangles". Draw yourself a couple (of stretched ones),
so that they are in the ratio of the two focal lengths involved, 400 and 600. Ie, make one 2/3 the size of the other. The "base" of
each triangle will represent the image size at the sensor. This - equal image sizes - is what you cannot achieve using the "400mm
FL on a crop body camera" idea.

You read/hear the term "reach" (q.v.) used in such a discussion, and this is the last time I'll use it, as it conveys not much useful
meaning. It has to do (AFAICT) with some related vague ideas about pixel density* on crop bodies* with a dash of resolution*
somehow cooking up some optical magic with modest means.

IQ or detail in images is mostly a matter of what size your subject subtends on the sensor, and of course, whether it is in focus.

Now to focus... Yes, mechanical aids such as you mention, AND good optical stabilisation are great. But also check that your lenses
are focusing correctly (my earlier post here) on the camera body. I have an f=30mm prime that liked to focus "just a bit in front"
of the subject. I had to dial in about 3 units of micro-AF adjustment on the camera to fix this. That change affects only that lens.

* These italics refer to terms that have proper definitions.

[/Call me a pendant, but]

arthurking83
06-12-2020, 6:55am
.....

The reason for the 600 mention was that the focal length of 600 can be recreated on a crop frame using a 400 lens. I have always had trouble settling the comparison in my mind. I have seen beautiful pictures of birds with prey (large an grub sized) that are sharp and clear. I have photos of ospreys that are not cropped that fill the shot. Right place right time.

I think the last time I posted about a lens it was related to the use of a 400 type lens and the weight. I am working on a solution (I hope), as mentioned the 600 size lens would involve a lotto win at least.

Therefore I am wanting to stay in the range of most manufacturers 400, the Tamron has served me well. I believe it is about 10 to 15% shorter than advertised. Using an used shooting target, holding the position of target and tripod I was able to compare the magnified result. The measurement was 120mm on lens a. and 100 on the Tamron. An otherwise excellent lens by most measures.

After some reflection I think that my focus problems are due to my less than steady hands. As long as I have had hands they have never been steady. The obvious fix is to become good friends with a monopod at least and a tripod when needed.

.....

It seems that Canon haven't made the 'update' path easy for you here too.

They have the lens that would appear to be perfect for you.. in that well priced 600mm f/11 for the R series of mirrorless cameras .. they just don't seem to have the ideal camera body.
Although in saying that the RP mirrorless body isn't priced to the point where you would need to sell any more body parts to have in your hands.

EOS RP + 600mm f/11 = (approx) $3000. This is obviously a lot of $s, but selling off the current gear will restore some semblance of health into your bank balance. (this is an option, but a harder choice to make .. hence why we tried to find a lens only solution)

Note that the first section of your reply above isn't quite true. It's 'seemingly' true .. but not really.

Remember that a crop sensor is just that .. a crop. That is, whilst your 400mm full frame lens may look 600mm-ish on a APS-C camera(like the 90D) the same can be said of a full frame sensor too .. just crop the image to the same framing.

So this generalisation that a crop camera 'increases' focal length is not really right .. but is 'seemingly' correct.
Where the seemingly correct parts makes it confusing is that in general pixel density plays a major part in the topic. Pixel density is how many pixels on a sensor for a given sensor size.
(approx) 24Mp APS-C is equivalent to ~60Mp on FF.

What that means is; if you have (say) a 60Mp full frame camera and a 24Mp APS-C camera and this magical 400mm lens that transforms into a 600mm lens depending on the camera body you choose you can replicate this magical transformation of '600mm focal length' on the 60Mp full frame camera too .. just crop out all those unnecessary out pixels .. exactly like the APS-C camera does!
If you crop the 60Mp full frame 400mm image down to 24Mp, you have the exact same result if you had shot the identical image with the 400mm lens on the 24Mp APS-C camera.

The easiest way to think of this topic of APS-C and focal loength equivalence is that APS-C = digital zoom. Very high Mp full frame cameras are not common nor very cheap. They tend to be marketed at the higher end of the range scale. Canon have their 5Dr series of 60Mp cameras that will allow a more direct method to see this 'reality' in action.

Like I said, the pixel density of the camera plays an important role in how all this pans out in real world situations.
Many APS-C bodies have about 25-30Mp, which equates to a 60+Mp full frame camera.

And Canon haven't really helped your cause with a wider range of choices at your disposal.
If they had an APS-C EOS R body to choose from, it may have helped a bit. They do have EOS R to ESO M adapters, but you don't really want to be messing with adapters(YET! :D). Native camera/lenses are much better than frankensteining up contraptions that could become problematic down the road.

So stick with DSLR gear, what you currently have to work with, maybe an light cash splurge(if possible) .. but no nuclear meltdown of banking resources to worry about!

Starting from the start tho:(and this part is important)

it appears that with the first image (Tamron 18-400mm) the image has been cropped. I doubt that the 18-400 lens would produce such low contrast IQ on the full frame image of that particular scene. Always try to provide as much info as you can on the processes you have performed(just saves trying to guess when answering).
On the second image, it appears to be the entire frame captured with the 100-400 lens.

So you have cropped the 18-400 image, but left the 100-400 image in it's entirely. Remember the comments above about "digital zoom" ... this is what you have done here.
So a more correct proposal for the above images would be that you have shown a '600mm equivalent' image from the 100-400+ APS-C combination, but as it appears that you have cropped the 18-400mm+APS-C image, it's more likely a '1200mm equivalent' focal length comparison now.

SO that important aspect of the situation needs to be cleared up(ie. if so, how much did you crop).

We already discussed that the 18-400mm lens has no hope to resolve the same level of detail as a 100-400mm lens will. This is not a lens law, but it may as well be as no product yet produced has proven that statement to be wrong. It's just a fact of life that more zoom range usually equates to less IQ out of that zoomier lens compared to the less zoomy type. And whilst this is somewhat true of the minimally zoomy lenses, like the 100-400 and the 70-200 type 3x to 4x zoom range lenses compared to prime lenses .. modern engineering has tightened the gap a fair bit.

But you have also made the comparison above even more uneven in that the 18-400mm shot has been disadvantaged even more so by using the lens wide open(f/6.3) and the 100-400 shot stopped down 2 stops(to f/8).
Remember that sharpness(or the perception of) is basically just contrast. more contrast usually looks like more sharp. Note that total brightness also makes images look sharper/less sharp.

Focus has also been affected, but I don't think it's a case of a lens problem. It has more to do with how the focus system actually works. it doesn't see pixels themselves as we see them. It has lines to work with. It's too complicated to describe here, but the basics of this topic are that the size of the subject in the frame(ie. the egret) will affect how good/bad/accurate the focus will have been set too in the image.
The exif in the images have both been majorly concatenated. ALl Maker info has been removed. Either check the settings in PaintShop Pro and see if it has a setting not to do anything to the exif data, or better still two other exif solutions.

1/. use DPP to convert raw images to jpg files. it's more than enough processing power to provide files for upload for the purpose of technical analysis.
OR
2/. find and locate a small exe file called InstantJpgFromRaw(IJFR). This has the ability to extract a jpg quickly out of the raw file.
if you don't have DPP, try method #2.

So more tips:

set the tamron to f/8 and forget that it has an aperture adjustment. This may provide the best balance between usable IQ and minimal ISO requirement. You could go to f/11 in really really bright situations.
Don't crop too hard.
Use lens hood(right way around)
Try to keep focal length near 400mm but not at 400mm .. do some static tests and see how it works. it could give half decent IQ at say 350mm or whatever .. I don't know, but you can find out.
(On a tripod, maybe shoot towards a picket fence, or neighbours roof or power lines. Try between 300mm and 400mm and see if there is any FL that can give a good balance between IQ and cropping allowance.)

Final tip .. try to get closer to subject. sneak up on 'em throw stuff at them to stun them .. do whatever it takes to get closer and zoom less. Less zooming(physical and digital) with these superzooms = better IQ.

Journeyman
06-12-2020, 8:30am
Thanks for the info Arthur, some time needed to digest and understand.

I was thinking about the loss of focus and sharpness. When I am setting up to take a photo the focus point (mostly one point) moves almost the length of the bird, above the bird and below the bird. Quite a bit of drift involved. (Mono/tripod required)

I did not lose the photos as often on my previous Canon a 750D. Entry level and more importantly no back button focus. That meant that when I took the shot the bird was within the frame. After some thought I realised that I don’t fire the shutter as confidently with the 90.

I am going back to shutter button release, maybe use the back button to close in to the subject then use the shutter button to complete focus and shot. I have read that many photographers don’t use back button. I have always said, for me, that too much choice can be counter productive.

Neither of the two photos were cropped. Reduced in size to meet the forum guidelines. The rocks are all beautifully sharp. I have 3 lenses all 400. I am still considering which one to keep, something has to go. Probably, quality wise the 100-400. Although there are reviews of Sigma’s 50-500. Too many parts to that I reckon.

As far as lens/camera combinations work, does it follow that the true processing power of a fast lens lies in it’s ability to make full use of the system, writing plenty of data to the card and thus allowing for the image to cropped and processed to a full frame equivalent?

I need to relax and produce good pics. Back to the one item menu.

As always your advice is gratefully received,
Kind regards, Journeyman

arthurking83
06-12-2020, 4:41pm
....

Neither of the two photos were cropped. Reduced in size to meet the forum guidelines. ....

Oh! strange.
The pixel dimensions of the T18-400 image seem strange then. 1200x1200 implies a crop.
I assume then by no cropping, maybe you mean in terms of resolution, and possibly only cropped out the sides out, but maintained pixel height dimension.
If that was the case, then yep, you haven't digitally zoomed for more magnification.

Do note tho: maximum pixel sizes of each image isn't similar either. 100-400 image is 1000pixels on the longest side, 18-400 as already said is 1200(and on both sides, but actually 1198x1200)
This does make a slight difference how the image is seen by us here on AP too.
If a lens doesn't produce 70+% image contrast(ie. low sharpness) displaying it at a higher resolution shows up more of it's flaws .. compared to the 1000(max) pixel image.

That isn't a major issue here as the 100-400 image is clearly more contrasty/sharp .. by a long margin.

Totally understand your concern with back button focusing, but it really is the better way to do it.
The other setting that helps with this tho is to use continuous focusing, not single shot mode.
So all the while you are holding the focus button the lens is continuously focusing on the selected focus point.

**caveat** I think Canons' use focus stop instead of focus on by default(I dunno, I'm not a canon user) for this button .. a Canon user will confirm.

But the effect you want to be using with this button/mode is holding the AF-On back button you are constantly focusing until you lift off(or not lift off) the back button, and then fire the shutter.

What this does, is potentially eliminate any missed focus shots.
The smaller the subject in the viewfinder, the harder it is for the focus spot to actually focus on this small subject. You may invariably(accidentally) focus on a rock, instead of an egret! ;)
Keeping the subject(eg. egret) large in the vf makes it more accurate.
If there is potentially any doubt if focus was hit on the egret because it was too small in the vf, then maintaining focus all the time(ie. continuous focusing) and shooting a few very quick frames in succession will(or should) result in one focused on the right spot.

Switching back to focus via the shutter release doesn't really help in this situation.

If you could repost the 18-400mm shot with a few changes it will help to assess what's gone wrong here.

If the shot was in raw mode, then run the raw image through DPP, convert it to jpg, resize via DPP too doesn't matter the actual size.
Reason for this is that DPP will not remove the focus spot info in the exif, hopefully will sow us where the focus was at the time of exposure.

jim
07-12-2020, 4:32pm
Would just like to note that I have never taken a photo like the first without the camera locking the focus like concrete onto the background and completely ignoring the bird just in front of it. Never.

Journeyman
07-12-2020, 4:38pm
Good day Arthur,
I have attached a resized copy of the Tamron shot. 1200 x 1200.
Apologies about the original resize. Spent a bit of time down on the river bank this morning. Very overcast morning, I will hang out for the next clear morning for some contrast.
Thanks for your expertise, kind regards,
Journeyman

arthurking83
08-12-2020, 3:23am
Would just like to note that I have never taken a photo like the first without the camera locking the focus like concrete onto the background and completely ignoring the bird just in front of it. Never.

It's not uncommon.
It depends on the size of the subject in the frame, relative to the size of the focus spot(or square).
As the size of the subject becomes relatively larger in the frame relative to the focus point, the chances of misfocus diminishes


Good day Arthur,
I have attached a resized copy of the Tamron shot. 1200 x 1200.
....

:confused013
Not sure on your method, but this resize has removed all exif data.
If you can explain your process, it would help to understand why.

What I recommend to do:
Open original image(hopefully raw file) in DPP, no editing at all, just hit the save button to convert it to jpg.
Once the dialogue box opens: use these settings:

1/ image quality to 5(on the slider on the right)
2/ tick the resize box on the lower left, only change the width number to 1000(pixels) make sure the lock aspect ratio tick box is marked too(it will auto resize the height)
3/ make sure embed ICC profile is tick marked and also that shooting info setting is set to include all shooting info(both near the bottom of the window).

These steps are only valid if the original image is an uncropped version of the one you uploaded, unless you have set the camera to shoot at a 1:1 aspect ratio for that shot.
If the first egret image is your original version of it, then nothing can be done about restoring the exif data.

If you have installed DPP on your computer(and I recommend you do so, if not), you can see for yourself the relative position of the focus point in the original image.

In DPP, with that (original) image in the display window, go to the tool bar and click [Tools] scroll down to AF Point display settings and then look for the 'show only AF points in focus'.
IN the lower toolbar(between the image preview and the film strip(icons of your images) you will see the tool to show/hide this info on the image. It's the third icon from the far RHS. Hover mouse over it and it will pop up a display saying AF point selection. When it's black it shows the focus square, when grey will not.
If the AF point has been recorded at the time of the exposure(may have been maybe not??) it will display a red square where focus was pointed at. If no red square(which could happen) then focus may not have been achieved.

If you set the af point setting to show all, it will display a grid of all the AF points as squares over your image. In Auto AF mode it may show multiple red squares to show you where focus was taken from.

Hope that helps

John Humpo
08-12-2020, 8:47am
Good question, personally a long lens is essential because you can't creep up on to many birds & you really do not want to disturb them so a crop sensor camera with anything from a minimum of 300mm up your 100-400 should do a fine job have you tried camera, lens matching maybe there's an issue with this, I have a Nikon D500 & use it with the Tamron 150-600mm G1 version for what you pay it does a great job as far as sharpness is concerned up to about 500mm but will still give reasonably useable results at 600, I also am lucky enough to own the Nikkor 500mm PF Prime it is superb & gives super sharp images but you always still need to get the basics right, focus, shutter speed, F stop etc. You do need to nail the focus on the eye or head area, if light allows try to use F8 (generally gives the best image quality on most lenses) & have a steady hand or use a monopod or tripod, I try to keep my shutter speed above 1/200's for stationary birds for maximum sharpness, for birds in flight heaps of practice & shutter speeds really need to be up there like at least 1/1600's, preferably 1/2000's & above to gain maximum sharpness IMO, also as far as converters are concerned don't use one if you want the sharpest images, unless you have a $12,000 prime lens, all the best.

Journeyman
08-12-2020, 10:41am
Good day and thanks,

I have attached an updated photo including the exif data.
To get to this copy - DPP - Aftershot - Paint for resize to 1200 long side.
My copy of DPP did not offer the convert and resize option. It is the last update to process CR3 RAW.

Learning as I go along, I saw the focus point button on DPP. The focus point shows as being directly behind the right wing, level with the wing tip and centered on a very handsome rock. It is not flying making things easy for me to focus on. I checked the balance of the sequence, the focus point is depressingly similar on all of the shots.

To be completely fair to the camera and lens combinations, they are both doing their jobs. Particularly if it is a rock you want me to take a photo of. The two specifics for me: 1. Involuntary hand movements 2. Camera technique needs some polishing. Monopod and tripod use for 1. More time in the field for 2.

I will check also the availability of a Kodak Instamatic. Just looking at the photo, there are things I like. The reflection, the scene itself.

Thanks for your comments and help, this trail has led me to some good info and editing knowledge.
Kind regards, Journeyman

arthurking83
08-12-2020, 11:52am
Good day and thanks,

I have attached an updated photo including the exif data.
To get to this copy - DPP - Aftershot - Paint for resize to 1200 long side.
My copy of DPP did not offer the convert and resize option. It is the last update to process CR3 RAW.

....

:confused013

Oh!
OK. In DPP, there is no convert and resize.
Open the original image(hopefully raw file).
Do nothing else, no editing!
Just hit the button just above the image.
This opens a new window to save the image incl some parameters.
This is both the convert AND resize window.
When you save, just be sure to have the file type in the Save as Type area as jpg.
Don't worry about file name, if this isn't important to you.

if this isn't an option in your version of DPP, what are the [Save] options?

If your file is raw type, this is the conversion AND resizing tool to use.
Note the image in the screen capture is not mine, downloaded from DPR for the purpose of tutorial. It is a CR3 file -> converted to jpg with only resizing and quality adjustments(as per my previous reply).
Note that the resultant jpg preserved the manufacturer data, and with that preserved the focus point used in the sample image.

See my screen capture
145454

Just so you know: maybe it's Aftershot, maybe Paintshop, one of them maybe both?? .. removing all the manufacturer exif data.
it maintains some exif data(common data only), but the vast majority is getting removed/deleted.

Also note: I don't think you would need to use a workflow type where you use DPP -> Aftershot.
I'm fairly sure that Aftershot is the raw file converter for Paintshop Pro's needs. If Aftershot doesn't recognise CR3 files, it could be an older version, and just need updating.
But if you use Aftershot(as the raw converter), you don't need DPP.

Hope that helps.

Either way, with your description of where the focus square ended up, then it sounds like misfocus (or misplaced focus) is the culprit for fuzzy egret then.
Most important that you understand this.

So with that info at hand now, I'll have a quick peek at what focus tracking does in your Canon .. (unless someone pips me to it! ;) ... noting that my Canon camera handling skills are severely lacking!)

ps. nothing wrong with an Instamatic, maybe only that it would feel a bit unbalanced with a 400mm lens hanging off the front(not mentioning the uber cool hacking that would be required!)
Also: rocks can be very photogenic subject matter .. with the caveat that wandering egrets don't impede into the frame! :lol:

Note it's all a learning curve. Anyone that tells you that they don't learn new stuff along the way no matter how long they been doing something ... a bit full of [S]B!... err .. some stuff.

Journeyman
08-12-2020, 3:28pm
Arthur, Mate,

You will be pleased to know as a last resort I reread the instructions, luckily found on this very thread.

Patience with an old mate sir, I have checked the data on PIE, seems to be intact.

Thanks for the instructions,
Kind regards,
Dennis

arthurking83
08-12-2020, 4:45pm
.....

Patience with an old mate sir, I have checked the data on PIE, seems to be intact.

....

:th3:

Plenty of that at my end ... being in a similar category myself :D

So for others reading this thread, the obvious reason for 'missed focus' is presented below

focus point location:
145458

Don't be discouraged, if I had a cent or two for every one of my similarly focused images .. I'd have the funds for everything. :p

A bit of a tip, but remember my perspective is coming from a Nikon centric environment .. so a Canon may operate a bit differently.

Try AI Servo AF in 'Automatic selection of AF' (zone). I read the manual, this is what Canon call it .. it's different in Nikon world.
Now you've bee advised to use single point manual selection of AF point(or zone or square .. whatever).
Usually this is best to use.
Full Automatic AF zone is not a good idea for serious users.
But the mode I described above(sorry no idea on Canon menu system how to get there tho!) sound similar to Nikon's 3D AF Tracking.


What this does mode does (AI Servo AF in 'Automatic selection of AF') is it should let you choose the initial AF point to start focus tracking with. Usually start at the centre point.
Then, as you move the camera(framing) relative to the subject, the AF system will automatically adjust the AF zone required to maintain a focus lock on the subject as you move(usually pan) and as the subject(usually an egret) moves off on a tangent.
There is sometimes a discrepancy between the subjects' movement and the operators ability to maintain the subject in the AF zone. The smaller the subject in the frame, the harder this process will be.

So I'll describe how it works from a Nikon point of view.

Set centre af point(the initial zone).
I have my AF-On(back button) set to start AF.
In Nikon world, servo focus(called continuous mode) I need to hold the AF-On button for the duration that I am focusing.
Remember I initially started with the central zone, but as I mis-track with the subject, and it moves a bit left of or higher than or whichever direction relative to the central AF zone, the tracking(Automatic AI in Canon land) then auto moves the actual AF zone for you.
You just keep tracking as best as you can, the cameras smarter, more accurate tracking ability makes you look more pro, even in your own mind(so to speak).

Hope that makes sense .. only thing I'm unclear about in Canon land, is if you need to continually hold the focus button down(whether the half press shutter, or back button) to continuously(Servo mode) the af system?

Reading the manual, it's almost as tho they imply(but not categoriclaly state) that you just initialise focus(ie. press and lift off) and it just continually focuses for you.

important note. This specific AF setup is not the same as full auto AF mode(not recommended).
This is auto tracking, simply for the purpose of holding the small subject onto any focus zone.

Nikon's system works very well .. dunno about you specific camera body.

Main point it costs ZERO $s to try, does not add any unwanted mass to the already weighty camera/lens setup! :lol:.. and if it works for 'ya .... :th3:

Note that you can very easily test this out right now! in the comfort of your living room.

If you can get to the menu system to affect the AF changes try it.
Then just move around inside the room you are in. Focus on something relatively small in the vf(not too large) say a door handle, or small trinket, or cup or whatever.
Start with the central AF zone, then move the frame a bit, but remember to try to keep the AF zone squares close by and you move about.. say get the AF subject as far left iwithn the AF area, a bit up, back across to the other side .. etc.

This AF tracking mode doesn't necessarily require that the subject is actually moving. It's also handy if you are shooting static subjects but as moving around trying various compositional styles.

A common moving bird capture style is to have the framing of the bird itself just behind the central AF zone .. so called .. flying into the frame. The common term of reference is called 'negative space' that is a bit of empty space where the subject is moving towards.
The theory is that 'we' don't care where the subject came from(or is looking away from) we are more interested in where it's going or looking towards.

Below is a visual representation of the 'theory' described above
145459

Hope that .. makes sense(to begin with) and helps.

Tannin
13-01-2023, 1:39pm
Late to the party here, but let's keep this simple and only cover the basics.

1: 100-400 II is a superb lens, your problems are not its fault.

2: No, a 70-300 won't do better. In fact no other lens will do better than the 100-400 II (other than mega-expensive exotics such as the Canon 600/4, 500/4, and 400/2.8).

3: Your main problem here isn't focus, it's the flare of the overexposed bright white bird against the dark background. For a bird that colour, you need a lighter background, a dull day with not so much contrast, or ideally both.

4: You get sharp focus on birds by selecting the smallest possible single point (usually in the centre of the frame but as you wish) and laying it on the bird. Set any focus buttons you wish on the camera body, they make no difference to the sharpness. Having ONE focus point and keeping it IN THE RIGHT PLACE is what makes it sharp.

5: With the best, most advanced image stabilised lenses (including the 100-400 II) you get three IS modes. Use Mode 3. All the time. No exceptions. There is a switch on the lens. Set it to Mode 3 and leave it there. This is how you get the image sharp from both main points of view (a) focus accuracy and (b) lack of camera movement.

==================================================================================================================


PS: How does IS Mode 3 work its magic?

Consider standard IS. The IS system in the lens (or in-body with some makes, either way) moves elements constantly to compensate for camera movement. Every so often it can't move far enough (say) up to compensate for you pointing the camera down so it resets to the centre and starts again. Meanwhile, you are looking through the viewfinder trying to hold the camera steady, but you can't actually see what the camera is doing or exactly where it is pointing because you can only see the scene AFTER the IS system has corrected it. You have got three motions going on - actual camera movement, the IS system compensation, and sometimes the IS reset movement. You cannot tell which movement is which in real time and can only guess and hope. Result is you cannot hold the camera properly steady. You get camera movement in the shot even though the IS is doing its best and you haven't kept the AF point in the right place so you often get missed focus too.

Now consider IS Mode 3. You can see exactly what the camera is doing because the IS system is inactive. Now that you can see what you are doing you can hold it very still. Not perfect (we are all human) but pretty good. Then you press the shutter (activating both the IS and AF systems) and because the camera started pretty close to still already, the IS system doesn't have nearly as much work to do and can add the final touches to get a brilliantly stabilised picture at insanely slow shutter speeds if you get it right.

Example:

http://tannin.net.au/upload/19/190414_113853-.jpg

(Canon 1D IV, Canon 100-400 II @ 400mm 400 ISO f/11 1/30th hand-held.)

William W
23-01-2023, 10:54pm
Later to the party...

To the OP - re read Post #17; then do it.

Additionally consider the selection of the AF Operation. On the 90D You have a choice of three.

For a shot like the one in your opening post, where the bird is moving, I would use AI Servo AF. You need to keep the (one) selected AF point on the bird.

There might be suggestions, or you might be tempted, to use AI Focus AF. I suggest you do not use that mode. My reasoning to not use that mode is - for most Photographers I would bet a Mars Bar they'd be using Continuous Shooting: for a novice Continuous Shooting usually plays havoc when combined with AI Focus AF.

WW