Exposure for birding

[KeithB]

I went birding on Saturday with my 150-600, and in general it worked pretty well, other than it is hard to get very close when you are with a group of 20 people!

The best 'hit' was a summer tanager.

So generally the birds were backlight against the sky, and tended to be under exposed. I also shot a heron flying close to the water with a nice reflection, but the white heron was over exposed.

Do you generally just set a -1 or so compensation when birding and hope for the best. It is hard enough worrying about focus and framing, but to add exposure on top of that...

[Frank Kolwicz]

Keith,

There is no one setting that will work in all conditions. Eventually, you simply have to check your exposure via the histogram and the “blinkies” on the LCD. This is especially true when working in full sun, as I know many bird photographers prefer. In full sun, contrast can change wildly as a moving bird exposes different colors to direct rays or moves in and out of shadows. Despite digital cameras’ wide dynamic range, compared to the good old days of slide film, for example, they just can’t hold details over the possible range of dark or black feathers in shade and white ones in sun in one exposure; something has got to give and, for preference, it normally is the dark tones. Burnt-out whites are usually more of a problem than deep blacks in images, the one exception that comes to mind is specular highlights.

Here’s what I do for a general, starting point when working in full sun with a Canon 7dII, EF600LIS(II), 1.4 and 2x extenders, which give effective focal lengths of 960, 1344 and 1920mm, respectively: Auto ISO set to 100 to 1600 maximum; Shutter Speed 1/1000; Aperture f/8 or f/11 (with the 2x); Spot Metering, exposure compensation set to ZERO; Single Point AF (but NOT the smallest point per Canon CPS service); Manual or AV Mode; Image Stabilization ON, Mode 1.

Normally, I make exposure adjustments by changing Shutter Speed first and only change Aperture when I’m out of Shutter Speed range; ISO is picked by the camera’s program within the set range and will top or bottom out before I have to make changes manually, so that gives a moderately wide range where I don’t have to do any compensation.

Whenever possible, I pre-check exposure by doing a test frame, looking for blinkies and the histogram. When exposure is not predictable, a bird with both black and white feathers, like a Black-necked Stilt, turning in the sun and moving in and out of shadows, I simply take my eye away from the viewfinder briefly and glance at the frame image on the LCD, losing as little time as possible from working the bird and making any obvious corrections before continuing.

When a subject is suitably still, I prefer to use manual focus via magnified LiveView or with a magnifying adaptor on the viewfinder – AF can be slightly off or fooled by heat waves, even when correctly adjusted for microfocus.

Four normal gloomy Oregon weather, however, I use a basic setting that works and seldom needs much adjustment. Most of the above settings are the same, only the Shutter Speed is reduced to 1/500 and exposure compensation is set to +1&1/3 (ETTR). I have had to use shutter speeds as low as 1/25 and gotten acceptable sharpness without an extender, but, needless to say, contrast was very flat!

[KeithB]

I understand, but I got one shot of a white heron taking off above the water with a nice reflection. I totally blew out the highlights on the heron. (Of course, I was using the camera's auto exposure, which I thought was supposed to be linked to the focus point somehow.) I was just thinking that starting with some -1 exposure might have saved that shot and subsequent shots of birds against the sky. If I shoot in raw than even if -1 isn't perfect, I can easily boost it in post.

[Frank Kolwicz]

Keith,

It sounds like your problem is not a universal exposure setting, but using an unfamiliar camera setting in an extreme lighting situation. If you had your camera exposure compensation set to -1, you'd risk a too-dark exposure on your next dark bird, so there's no real gain on average. Also, the effects of underexposure on the darker background can have consequences for the final image in some cases, affecting how you can use the image.

Spot metering would have helped in that case and even +1 metered directly on the white bird should not have blown out (zero would make the brightest area, the bird, mid-toned, +1 slightly brighter and more nearly the correct exposure). The use of spot metering can be problematic when using off-center focus elements and there's a difference between what the meter sees and what the focus sensor locks-on; in that case, there's a good reason to use center focus, OneShot and recompose, which, of course is difficult for moving subjects and sudden opportunities.

Some shots just get away, no matter what.

Frank