How to Focus Macro Pictures

Focusing at macro distances and why AF isn't for macro

So why can't I use AF? ‘Cause you're trying to focus on the eye of a bug, maybe even part of an eye of a bug. We're talking about a target that's less than a millimeter across, and holding that point during focus, and then maintaining that point after focus is achieved. Try it if you must, but you'll discover what thousands of others have said: macro and AF are not happy together, and that's just the way it is, at least with today's technology.

To quote from CaseyJ on the DPReview board:
"...it is very important to use manual focus. Acquire focus on the subject, then very slowly and gently rock back and forth, do not change focus. You will see the focal point move as you rock. Time the shutter release to coincide with the focal point passing over the subject. Ignore camera shake as the flash and faster shutter speed will freeze the subject. All you need to worry about is getting the very shallow DOF to fall on your subject and that is where manual focus and timing your movement comes in. No one can hold the focal point perfectly in place without a tripod or other support so you have to learn to make your movement work for you instead of against you."

Focusing Rails

After you’ve spent 3 minutes moving a tripod back and forth a quarter inch at a time, you’ll invent the focusing rail in your head. Of course, it’s already been invented, but you’ll immediately discover why such a tool exists. If you’re unclear of its function, here’s the deal:
For most macro work, you set your focus before you start shooting, and then move your rig back and forth to achieve focus. At 1:1, your DOF is just a millimeter or two. Making that sort of adjustment is very hard, so the focusing rail allows fine control along the lens axis.

Next: Bonus Macro Tips