[Cailean]

So I bought this closeup filter set (+1, +2, +3) cheap on eBay, but I have no idea how to get the best use out of the lenses... everytime I try, I can't seem to get the damn thing to focus OR it doesn't look any different than without the lenses... any help?

[shuttertalk]

I haven't used one before, but aren't they supposed to magnify the image? The bigger the number, the greater the magnification... that's the theory anyway!

Funny how you can't focus with them... how close are you to the subject? Maybe try standing a bit further back?

[slejhamer]

First, make sure you are stacking them correctly: strongest should be closest to the lens.

Sometimes you don't need more than +1 or +2, so make sure you're not overdoing it. Your DOF will be greatly reduced, and you may find that auto-focus does not work very well.

Think about it this way: When the camera is set to focus at infinity, the +1 diopter moves the focal plane to 1000mm (1 meter) from the lens (or maybe it's from the film/sensor plane; I always get that part confused.) A +2 diopter moves it to 500mm, +4 to 250mm, etc. Each + diopter is a halving of the focal range. (Canon smartly names their close-up lenses according to this focal length: their 500D is equivalent to a +2 diopter, 250D is equivalent to +4.) So these close-up lenses are not really magnifying the image, but they are allowing you to focus closer and closer to the subject making it appear larger on the sensor or film.

As your focal plane moves closer and closer, your DOF gets razor thin, so you'll want to use a very small aperture setting. A tripod will help, as will a focusing rail which allows you to move the camera in small increments (keep the lens fixed with manual focus, and move the camera back and forth.)

[gd]

wow.. that's cool... I have never used one or anything, but that description sounded pretty detailed for 2 paragraphs... well done slej!