Wednesday, October 1, 2014

Hit and Miss

Here are two pictures taken barely a second apart. One is nicely focused and the other is completely out of focus. I like both of them. You may not like the second but I like how the bird and the feeder are clearly identifiable despite being entirely out of focus.

One of the selling points of DSLR cameras is something called a burst rate. Depending on the camera and several other factors like file size, the picture quality you chose to use, shutter speed, and other settings, the camera will allow you to shoot a rapid burst of frames. The idea is to capture the peak of action - the "decisive moment" as Henri Cartier-Bresson, a well known French photographer, termed it.

Personally, I don't find burst rate to be very helpful in this regard. If you anticipate the peak of action too soon - and even a mere second can be too soon - you may be in danger of having reached the limitations of your camera just milliseconds before the actual decisive moment.

What happens when you hold down the shutter button in a burst is that the camera continues to take frame after frame as fast as it is designed to. If you continue to hold the shutter button down, the camera's processor will reach a point at which it's buffer fills and it can no longer continue to take pictures.

Even if you are holding the shutter button down, it will not take a picture until the on-board processor has room enough to add more information. It is the point at which you can no longer take a picture that I have often found to be the real decisive moment.

The method I use is to set the shutter on high speed frame rate so that the camera can take more than one photo after another if you choose to hold the shutter button down, but to then use it judiciously, shooting a quick frame or two here and there as the action develops. That way, the buffer does not fill up and you can continue to take many frames over a much longer period of time.

It takes a little more background knowledge of your subject in order to anticipate the action rather than simply using a scatter gun technique hoping to get the best shot.

In the sequence of the osprey defending her nest from an interloper, notice how little difference there is between shots 3, 4 and 5. This was despite trying to shoot sparingly.

If I had simply shot a burst as fast as I could, the buffer would have filled with about twelve frames looking exactly like those three and I would have missed any action that followed in frames six and seven.

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