If you fancy a bash at extreme macro, then this is the lens for you. Most "proper" macro lenses offer 1:1 reproduction, which means that the image of an object on the sensor is the same size as in real life. You can fill the frame with a postage stamp. But the unique Canon MP-E 65mm starts at 1:1 and goes all the way up to an amazing 5:1. At that magnification, you can fill the frame with an object that's only 4mm across.

Using this lens is deceptively simple. There's no autofocus. You just adjust the lens to the magnification you want, move the camera closer to or further away from the subject until it's in focus, and take the picture. Or you can set the working distance and then use the magnification control as a focusing adjustment and turn it to bring the object into focus.

But using this lens is also deceptively difficult, for several reasons.

• The depth of field at high magnifications is minimal, so getting an accurate focus is very tricky. Using focus stacking software such as CombineZM (open source) is probably going to be helpful too.
• Vibrations in the camera can cause problems at high magnifications, so you need a very stable camera mount. And of course the usual stability-enhancing techniques such as mirror-lock up, remote or timed shutter release, etc.
• Lighting is a challenge. Although the lens says f/2.8, at 5x magnification it's effectively f/16. So you need lots of light, or a slow shutter speed.

If you're tempted, Wayne Schmidt has written a very useful guide. Are you up for the challenge?

Suggested extra: You might find the Manfrotto MN454 micropositioning sliding plate useful when mounting this lens on a tripod.