Originally posted by ftpaddict Although doesn't the longer focal length undermine every attempt at hand-held macro photography? Longer focal length = longer minimum shutter speed to avoid camera shake.
When you get into macro photography, particularly at the scales where you're looking for a longer lens to get enough working distance, hand-held shots become problematic no matter what lens you use. There are several reasons for this:
1) In macro photography the lens focal length is less of a factor because you are typically repositioning the camera so that the subject fills the frame. So you move closer to the subject if you are using a lens with a shorter focal length, and vice versa. This is why depth of field in macro photos doesn't depend on focal length - only on aperture and reproduction ratio.
2) You're so close to the subject that small camera movements are very obvious. If you look through the viewfinder at a subject 10 feet away and rock back-and-forth in a sideways direction a centimetre or two, you'll hardly be able to see the effect. But at a distance of only a few cm it means that the subject may move completely out of the frame. Thus, the effect of any camera motion is magnified.
3) SR becomes pretty much useless at macro distances because it can only compensate for rotational movements of the camera. At normal distances this works great, since translational movements (as in (2) above) don't cause much motion of the image. But at macro distances translational movements dominate and SR is powerless to counteract them.
4) Depth of field is so shallow at macro distances that fore-and-aft movements that are normally harmless can also ruin the picture. As mentioned in (1), for macro work the focal length really isn't a factor in depth of field.