Cloudy Days, take 2

For bird photographers, the other convenient aspect to cloudy-day shooting is that it provides some very flattering backgrounds for species perched on bushes. Shadows are minimal.

And with the sun behind the clouds, there are no distracting hotspots (dappled sunlight) behind your subjects.

It's handy to use fill flash if you can do so without startling your subject. Appropriately used, it provides "snap" and fills in shadows--particularly useful if you are shooting in mid-day. It also puts a small "catchlight", or bright reflection, in the subject's eye to give it sparkle and depth.

I use a flash extender called a "Better Beamer" that is specially designed for use with long telephotos and zooms. It's easy to use, weighs only a couple of ounces, and fits easily into your camera bag. You can learn more about it here.

How to use flash effectively in the field is a subject worthy of a post all its own...or several. We'll talk about that soon.

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Image: Great Egret, St. Augustine. 1/1250 @ f/5.6, ISO 640, Canon 70-200mm IS zoom. Better Beamer set at -2 for flash fill.

The case for cloudy days

Last week I went up to St. Augustine (FL) for a two-day visit to the Alligator Farm rookery, one of the best places to observe and photograph nesting birds from close range. The forecast was ominous -- two days of thunderstorms, clouds and rain -- but the hotel room was already booked and prepaid, so rescheduling wasn't an option.

I managed to get to the rookery by 4 PM on Monday, and was greeted by cloudy skies but no rain -- yet. I was surprised that there were so few serious photographers on hand. Overcast and cloudy days provide lots of great avian shooting opportunities.

Photographing birds in flight is actually easier on cloudy days than on sunny ones. When the sun's out, you must plan to shoot only those birds flying more or less into the direction of the light. On cloudy days the light is more omnidirectional, and good exposures can be had regardless of the bird's flight direction.

The lower contrast simplifies exposure, too. Well-exposed shots will render lots of underwing detail. On a sunny day, that detail is difficult to preserve without burning out the parts of the bird that are in direct sunlight.

What's a "well-exposed shot" for birds in flight on a cloudy day?

You always want to set your exposure so that the sky is rendered as white, or nearly white. To do this, set your camera for manual exposure, and set your aperture to f/5.6. Meter on the cloudy sky (no branches or foliage in the frame) so that your needle is at null (or "+0"). Then, adjust your shutter speed so that the meter is displaying 2 stops overexposure ("+2").

For birds in flight in cloudy weather, (or any weather, for that matter), you'll need sufficient shutter speed to stop the action. There are lots of variables to consider (do you want to blur the wings somewhat? Is the bird close to you, or flying 30 feet or more overhead? etc.) but in general a shutter speed of about 1/1250 or faster is desirable. If, having followed the instructions so far, your shutter speed isn't 1/1250 or faster at f/5.6, consider boosting your ISO setting until it is.

With my Canon 40D and 50D bodies, my standard ISO setting is 400. In cloudy weather, I may need to boost that slightly, maybe even at high as ISO 1000, to satisfy my requirements. To summarize, they're:

• Manual exposure mode
• Set f/stop to f/5.6
• Meter off the sky, then adjust shutter speed by 2 stops to render the sky as light gray
  
• To stop action, use a shutter speed of 1/1250 or faster
  
• Adjust the ISO upward (i.e., to 500, 640, or 800) if light is insufficient to meet the above conditions.

Tomorrow, I'll blog about why cloudy weather works for subjects hanging out in mangroves, etc., as well!

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Image: Immature White Ibis in flight; 1/1250 sec. @ f/5.6, ISO 800; Canon 50D and Canon 70-200mm f/2.8 zoom lens.

View all my images at the Wild Images Florida website.