Focusing on Birds

[Michael_2010]

I’ve been trying to capture some decent bird shots and it has been pretty hit or miss. Actually, it has been more miss than hit. What is the usual starting point for you bird photographers, when it comes to focus options and metering?

Last weekend I spent a morning just playing with AI Servo, high-speed continuous shooting and evaluative metering. I learned that I can get a whole bunch of shots, fill up a memory card quickly and end up with some lovely shots of tree branches with fuzzy birds sitting on them. How do I avoid that and hold the focus long enough to get one or two good shots of the bird instead of the leaves and branches surrounding the bird?

Btw, I’m not shooting at a staged feeder with perch, etc. I’m on the move in bird sanctuaries trying to quickly react, when I hear and see a bird within my range.

[dlambert]

First, check your shutter speed to make sure that you're not getting motion blur that you're attributing to bad focusing.

You'll definitely want to be aware of the focus points you're using. Check a few of these, either in-camera or using Canon's software (I assume you're shooting Canon via the AI Servo reference). AFAIK, other software rarely shows these points, but they're valuable in seeing how the shot was taken. In any event, if you're inadvertently focusing on something other than the bird, then that's a good place to start. If you're shooting in a "busy" environment (branches, etc.), you'll probably have to pick a focus point and hit the bird with it, though that's incredibly tricky if it's moving.

You might also want to look at some of your continuous-shooting sequences to see if there's a difference in focus between your first shot and subsequent shots. I recently learned some fairly interesting things about Canon's AI focus -- in my case, though, I was at least as interested in shooting speed as in focus lock.

Do you have an example (w/ EXIF) that shows what you're running into?

[Michael_2010]

When I get home tonight, I will pull up a few examples.

Yes, I was using a Canon 7D and had never really used the AI Servo function. I thought it might be just the thing for catching some birds in flight. It seems as though once it has locked onto something slightly out of focus it sticks with being out of focus in the subsequent frames. Would you use AI Servo, or go with one-shot focus? What about metering? Would you stick with spot metering for a bird perched on a tree branch?

Thanks for the link. I'm reading through it now.

[dlambert]

Actually, the 7D has a lot more control over autofocus operation in AI Servo mode than I've got w/ the 40D (focus-priority / release priority). I think those are in C.Fn III-2. The goofy way it switches priority on the second (and subsequent) modes is what buggered me up. You might want to try AI Focus, as it's supposed to lock focus on the first shot and then switch to AI Servo if the subject moves.

You've also got a ton more control over how autofocus works than I do -- see this article. Specifically, I'd expect that AF Point Expansion and Zone AF might come in handy, but those are just guesses until you can tell whether the camera is focusing on the wrong thing vs. not achieving focus lock at all, if that makes any sense.

I'd leave metering as-is (evaluative) unless you're seeing problems with exposure.

[sk66]

I don't know Canon very well, but I'll tell you how I set up w/ Nikon.
I am in Continuous focus servo with shutter set to continuous high. I'm using spot metering and dynamic focus point (51 points or 51/3D). I also have my focus delay set to "long" (usually). This works quite well on my D3...works for crap on a D90/D200. I've also switched the release mode to "focus" instead of "release+focus" as I never use the out of focus images anyways....

With the D90/D200 I would use similar settings, but center weighted metering and either area autofocus or Dynamic 9 or 21 points.

I have found nothing that works reliably well for the little darting birds at ranges close enough to get decent image size...best bet there is trap/zone focus and luck.

For a bird on a stick, use whatever mode you want, but unless you are good w/ exposure compensation spot metering might not be the best choice (many birds are very light or very dark). Many find manual exposure for the general scene to be easiest (I don't usually go this route). In fact, I believe it is easier than becoming very fluent in the other exposure modes.

[Michael_2010]

Thanks for all the great info!

I got the 7D, because of all its focusing capabilities along with a few other technical improvements. However, I would be a liar, if I said I had a full understanding of all those options just yet. I tend to take things a step at a time and I am just now exploring the possibilities with birds. My first serious outing last weekend yielded some very disappointing shots and I would like to go out better prepared and informed next weekend. I see that I have a lot of reading ahead of me the next couple of days.

[inkista]

I'm weird. I often use One Shot focusing and the center point. But my defaults are center point only, center-weighted metering, AI Servo, back-button AF (w/* and AF-ON buttons reversed, with shutter for AE-lock and back button for AF start), and short controlled bursts, resetting the AF between bursts. So far, I see no need to change.



I keep C1 programmed with my birding settings, since the back-button stuff is buried in the C.Fns and it's two separate settings for me, so I just use C1 to turn it on and off. I tend to default to Av @ f/5.6 and iso 800 to get the shutter speeds I've found work for me and my 50D+EF 400mm f/5.6L USM.

If you have a lens with a focus limit switch use it. It'll help cut down the AF time by reducing the "search" area.

[sk66]

Inksta,
One shot focus?!!
Maybe for subjects moving parallel, but man... what do you get, 1 or 2 out of each burst if you're lucky?

Nice Kite pic BTW...

[inkista]

Originally Posted by sk66

Inksta,
One shot focus?!! Maybe for subjects moving parallel, but man... what do you get, 1 or 2 out of each burst if you're lucky?

I know. It's sick. But definitely one shot for perched birds. And I ridgewalk for my hawk shots when they thermal along the ridge a lot of the time, so they often are moving parallel to me. A lot of the time, they're going so fast I'm only gonna have them in range long enough for two or three frames anyway, and one-shot just seems to be FASTER.

Also, I short-burst a TON. I'm far more liable to fire off three short bursts of only two or three frames each, than a long 12-shot burst.

These are probably just bad habits I picked up from my XT days.

Oh, and I completely agree with you on little darting passerines: you just stop down and pray. I really really wish my Canons did trap focusing. I have yet to catch a hummingbird dive-bombing me.

[Michael_2010]

Absolutely beautiful photo!

Okay, I figured out how to review my focus points with Canon's DPP software and I'm hitting the target pretty well. Now I think I have a bigger problem with lousy lighting and general exposure more so than focus. Could also be a distance problem.

This is a tight crop of a Red-bellied Woodpecker:



Camera Canon EOS 7D
Exposure 0.001 sec (1/800)
Aperture f/8.0
Focal Length 300 mm
ISO Speed 400
Exposure Bias 0 EV
Flash Off, Did not fire
Canon Flash Mode Off
Continuous Drive Continuous, High
Focus Mode AI Servo AF
Metering Mode Evaluative
AIServo Tracking Sensitivity Standard
AIServo Tracking Method Main focus point priority
AIServo Image Priority 1: AF, 2: Tracking
AFAssist Beam Emits

This is a screen capture showing the AF points:



What are your thoughts? What if I had used my speedlite on this bird?