Wide Angle Manual Focusing

[Sdison]

Hi all,

I've got the opportunity to pick up an 11-16 tokina on the cheap (like really really cheap).The only issue with the lens is that it has a broken AF motor, meaning that I'll need to always manual focus it.

UWAs are renowned for their large depth of field and short hyperfocal distance. Will it be as simple and setting it and forgetting it at the hyperfocal distance when I'm shooting landscapes?

I understand that it'll be harder to use it for things other than landscapes or at apertures wider than, say, f8 or f11 because I'll need to be a fair distance from my subject.

I jumped onto DOFmaster to check out the 'near limit' of the acceptable sharpness at various focal lengths and apertures.

It varies from 35.2cm at 11mm f16 to 237.9cm at 16mm f2.8.

I suppose my question really is whether I'm going to have a difficult time with landscapes (it'll be used 99% of the time for this). The only other time i can envisage myself using it is indoors for large group shots, where I will most likely be standing a couple of metres away anyway.

[arthurking83]

.....

I suppose my question really is whether I'm going to have a difficult time with landscapes (it'll be used 99% of the time for this). The only other time i can envisage myself using it is indoors for large group shots, where I will most likely be standing a couple of metres away anyway.

NO!

On your D7000, you have the option to use liveview for focusing. Use this instead of generally inaccurate DOF tables and hyperfocal calculations.

Since getting the D300 all that time ago, what I've tended to do in the majority of situations for finding the best focus plane(for landscapes) was to quickly find a nice sharp section in the scene using liveview, turn Lv off(setting back to Ch mode) and fire off whatever relevant exposures I wanted.

That is, I used Lv mode only to find an area to focus on, turned it off and just shot as per normal.

In all other situations where Lv wasn't used, it was probably for two reasons ..
1. focus point was either beyond about 2-3m or so or wasn't as important as just getting the scene captured in the first place.
2. (rarely) the lighting conditions overwhelmed the display during Lv operation.

As long as the lens as is, is cheap enough there's no reason not to get it. I'd just make sure that the price of the lens as is doesn't exceed 75% of a new similar item when added to the cost of getting it repaired.

That is, if a new version of this lens cost $600(grey) and the cost of a repair job came in at say $400 .. then the amount of money you'd want to spend on acquiring the lens would be no more than say $50.
My belief is that a new lens(even a grey one) is still the better option, but at the right price a clunker is still a viable alternative.

[Sdison]

This is certainly in the 'right price' category, so thanks for the advice.

Just to clarify re focusing, do you use LV after you set the lens to infinity to double check that it's sharp?
Or do you find a section that is sharp so that you can refocus using the viewfinder?

[arthurking83]

I set the lens to where I think it should be focused, then check with Lv.

My UWA lens of choice at the time was 99.999% the Sigma 10-20mm, and read many reports of how unsharp it can be at the edges of the frame.
Well to a degree this was true, but the reality was that this was only in the last 1% of the very corners of the frame.
If just you focused the lens say at 1m distance, and not in the corner of the frame(which may have also been at the 1m distance mark) the image captured may have been blurry at the edge of the frame.

Obviously the lens suffered from field curvature, so if an element in the edges of the image needed to be rendered sharply, I'd confirm this using liveview, and the subject would be rendered sharp.

[Lance B]

Hyperfocal distances can be helpful, but they might be a little dated with the hi-res bodies of today, meaning that sharpness is more pronounced in the area that are in focus and therefore you will possibly notice a drop off to the OOF areas sooner than with the lesser res bodies of many years ago. Hyperfocal distance is just a guide and no matter how you cut it, there is an area of absolute sharpness and then it drops off either side of that and hyperfocal distances are about how big you are displaying the photo and what the viewing distance is from that photo. So, if you are displaying a 1.5mt wide photo from your D7000 taken with a very wide angle lens at f11, hyperfocal will show up very how quickly the OOF areas drop off from front to back of the image due simply to the size of the image and viewing distance. However, the same image displayed at 300mm wide on a monitor will more than likely look sharp front to back.

However, bearing this in mind, I would only use hyperfocal distances in certain situations when using wide angle and extreme wide angle lenses or any lens for that matter where you are trying to convey depth and differnig subject points of interest. If you are shooting very wide angle or extreme wide angle with some major foreground interest, it might be better to focus on that rather than using hyperfocal distances as what is in the rear of the photo is of less importance as it appears so small and far enough away that it may be of little consequence for it to really need to be perfectly sharp.

You must make evaluations on what you are trying to do with the photo. For me, there is nothing worse than with a wide angle photo with some foreground subject matter that is slightly out of focus distracting from the overall image and for me, many very wide angle or extreme wide angle photos need some foreground interest or leading lines to make them work so as they don't appear flat.

I am not saying that any of the following are great photos, many are just photos of an area, but using the above thoughts the subject matter in the foreground would be quite ditracting if they were slightly soft and without the foreground interest would be quite flat and uninteresting.

With the following photo, I could have used hyperfocal distance even though I was using f13, but I chose to make sure that the rock was perfectly sharp and make it stand out with a slight 3D feel to it. As you can see, the rear is not pin sharp, but sharp enough to not be a blur and you can see what the rear is.

http://www.pbase.com/lance_b/image/126543231/original.jpg

The plants in the foreground here give a sense of depth and would be (IMO) a very flat and less interesting photo had there been no foreground plants framing the photo and if I had focused via hyperfocal distance then they would be slightly soft and therefore distracting.

http://www.pbase.com/lance_b/image/126748267/original.jpg

Other examples of where I focused slightly to the front of the image rather than at hyperfocal dictance.

http://www.pbase.com/lance_b/image/151821712/original.jpg

http://www.pbase.com/lance_b/image/151875403/original.jpg

[Sdison]

Thanks Lance. that's really insightful. I think my issue is that I'm just scared of manually focusing, and this might be a good way of kicking myself into gear and learning to do it properly. Knowing the focusing methodology to use I think helps greatly.

[ameerat42]

...I think my issue is that I'm just scared of manually focusing...

My fear is that AF will not always work properly.

(Scary stuff this photography!)
eek: m.