Thanks Ed.
I hope stacking proves helpful to you. It does take a bit of experimentation to work out an appropriate step size (movement between each frame). It's important not to allow too large a step else you'll end up with out-of-focus bands at various depths through the image.
Adam,
You're dead right there Adam
. However fortunately quite a few do and sooner or later even one of the most skittish species will hold still long enough for you to take the 2 to 6 shots necessary to get your stack. I'm repeating myself here, but that's why I always start with the nearest (most interesting) part of the subject, as even if you only get the first shot off before the subject moves or disappears it's often worth keeping - and the odds of getting a keeper improve with each focus step.
I frequently plan for 4 shots but only get 2 or 3 before my subject moves. More often than not even 2 frames are worth stacking and you get more dof than with the single shot. I reckon it takes me about 5 secs to recompose for each frame so with 4 frames that's 15 secs that the subject needs to stay still from the moment I fire the first shot.
Another advantage of stacking is that you can afford to use a slightly wider aperture. While this means shallower dof per frame it generally means better IQ as there is less softness due to the diffraction limitation effect. With my D300 + Nikon 105mm Macro lens I usually shoot single images (no plans to stack) at an effective aperture of f/16 - f/18 whereas when I shoot stacking frames I set the aperture between f/11 - f/14.
Bruce
