Focus Issue & an Image for Discussion Purposes

[snyderman]

Hi All:

The imbedded image is very typical of my captures. Part of bird (or other subject) in great focus, but not the entire subject. The image clearly shows wings and underbelly in decent focus, but head OOF. Below the image, standard setting and xif data about this image are posted.

Obviously, I'd like to get ALL of the subject in focus. Your comments and suggestions are appreciated. Thanks in advance.

http://i14.photobucket.com/albums/a310/dsnyder160/IMG_9767.jpg

Standard settings on my 30D are:

Center Point Focus; Spot Metering; AI Servo Focus; Manual Mode

xif data on the image above:

Lens: Sigma 70-200 f/2.8
Focal Length: 200mm
Subject distance: ~12'
Exposure Time: 1/500
Apeture: f/4.0
ISO: 400
Crop on image: Nearly 100%

Questions:

What setting changes can you recommend to see more uniform focus across the subject in this example?

Are my "standard settings" appropriate? The camera was setup initially for basketball shooting

Wrong tool (lens) for the opportunity?

What the heck is going on here? This again is a very typical result for me.

Thanks again in advance for your thoughts and ideas.

dave

[mikeivan]

That is a nice sharp image for 100% crop. Is this a Depth of Field issue? My calculator shows a DOF for your settings of about an inch in front and behind your focus point.
http://dofmaster.com/dofjs.html
When shooting birds, I always try to focus on the eye. Also, when I get that close (seldom), I try to stop down to f/8 to get more DOF. Perhaps others will have additional suggestions.

[nwa2]

Taking MIKEIVANs numbers, it is easy to see that if you are hand holding, you could be swaying forward or back and taking the subject out of the region of focus.

Use a monopod and smaller apertures and give yourself more DoF.
Which AF setting are you using, try AI-focus.

[snyderman]

That is a nice sharp image for 100% crop. Is this a Depth of Field issue? My calculator shows a DOF for your settings of about an inch in front and behind your focus point.
http://dofmaster.com/dofjs.html
When shooting birds, I always try to focus on the eye. Also, when I get that close (seldom), I try to stop down to f/8 to get more DOF. Perhaps others will have additional suggestions.

Thanks for your thoughts. DOF is probably the issue. And yes, stopping down would probably help with that. I'm not really steady with the bigger lens, so keeping shutter speed at 1/400 or greater is usally a priority.

As far as focus goes, I'm usally pointing the center focus point at the body of the bird because it's larger. Could be exactly the cause of the in focus wing and underebelly and OOF head/eyes.

Just have to get better at the whole thing, I guess!

dave

[snyderman]

Taking MIKEIVANs numbers, it is easy to see that if you are hand holding, you could be swaying forward or back and taking the subject out of the region of focus.

Use a monopod and smaller apertures and give yourself more DoF.
Which AF setting are you using, try AI-focus.

Thanks for your thoughts. As a rule, the camera is set to the AI Focus because HS basketball is another area of interest that I shoot regularly.

As mentioned above, I do have a difficult time keeping still with the heavier lens on the camera. Really good success using the 85mm, but the 200 weighs about 5x the 85!

dave

[Froggeh]

if you're struggling with the weight you may want to either switch to the canon 70-300 or (this may sound stupid) try some weights. i'd say you're just too far away for great detail on it, and you need to aim for the eye with a suitable depth of field.

you might also try ISO 800 if the light isn't good enough for 1/1500sec - the small birds like finches (hummingbirds for extreme examples) move a lot in tiny motions as their hearts beat so fast.

personally I prefer AI-servo - just mho.

cheers,

j.

[gasrocks]

You need to MF on the eyes of the bird. There is little DOF with long lenses, especially up close. I often use very low shutter speeds so that I can use f/13 (for example) to get a clearer/sharper pix of the whole bird - still focusing on the closest eye.

[BradM]

There have been some recommendations that would help but then others that I think are taking things to far the other way and could only create further difficulties.

The first that strikes me is the number of 1/1500th of a second for a shutter speed, raising the ISO to get higher shutter speed is a reasonable suggestion but where the the specific number of 1/1500th came from I don't understand. Heck with proper technique and a bit of luck, shutter speed shouldn't be a worry. With the below shot I think I got more than a reasonable amount of detail for the focal length and shutter speed on a live subject.

It is a shot at 1400mm (500mm f/4 w/ a 2.x & 1.4x extenders stacked) @ 1/80th of a second, it was taken mounted on a gimbal and tripod but not locked down, nor was it shot with any long lens techniques like remote release or MLU.

http://i7.photobucket.com/albums/y259/Bradklr/1400mmgoose.jpg

For a bascially static subject it is about getting the focus point in the right spot with the proper amount of dof to get the shot you want. Too many people will lay the focus point over the body and trust to luck. Placing it over the eye is the right way to do it. If the finding the eye is too difficult then try to grab at least the head, if that is a problem then one must stop down to bring the eye into the range of focus.

For these flight shots I was using the 100-400mm L handheld with available light, but because the bird was moving I had concern about getting enough dof because I couldn't stay on the eye or the head as the bird moved through. So I stopped down to f/8 and had a shutter speed of 1/250, ISO 800, + 2/3rd's EC.

http://i7.photobucket.com/albums/y259/Bradklr/hummerorb10.jpg

On the focus mode, AI servo is the way to go, AI focus is a bastard child that barely works in any circumstance. You may move, your subject is moving using AI servo and keeping it active while shooting will help increase the number of good images.

On stopping down to around f/13, personally I think that is a bit of overkill, there are times when one is close and needs additional dof but as the subject moves away dof increases. Having the eye sharp is the priority, the areas of the head and breast are next depending on the subjects posture or pose but beyond that it the viewers eye will accept oof areas and often find the image pleasing.

But depending on the lens getting above f/11 can start to introduce diffractions effects lowering image quality, especailly if one needs to crop down to pull the subject up in the image. If it is about getting crisp images try to not to shoot with settings that may very well pull the image quality down. Self defeating and frustrating to say the least.

From the wing to eye, this dowitcher is maybe .5" deep and to the next bird about 3 inches, but I stopped down to f/9 with the 100-400mm @ 400mm to get the shot sharp and have a nice fall off to the following bird. My shooting distance was 12-15 feet, lying on the dock at eye level handholding the lens @ 1/500th.

If I had tried to stop down to pull both birds into focus at this distance I would have to go so far that diffraction certainly would have been introduced and while the rear bird would have been sharp, the forward would have lost much of it's detail and been much more muddy in look.

http://i7.photobucket.com/albums/y259/Bradklr/dowitcher85b.jpg

So bottomline I would boost your ISO to increase your shutter speed and allow you to stop down, if you have difficulty handholding at or below the shutter/focal length rule of thumb use some support, stay with AI servo and work to get that focus point over the eye or at least the head instead of the body. Hope this helps!