I bought this lens to shoot Kodachrome and Ektachrome slides again. Yes, much faster than scanning - just snap your photos! It also works great with old photo albums. This magic is "Flat Field" - no noticeable distortion, a flat object will be sharp and sharp like a razor at the same time. It actually took some effort to figure out how to do all this - if you want to do the same thing you need flat lighting just like you need field plane. I use a studio flash (but a small one will do). and sew a sheet of paper. Use a beam cone or otherwise limit the flash so it doesn't accidentally light the front of the slide or you get reflections (you might even see camera flares in the dark areas of the slide). a small self-made holder and behind it a sheet of paper with a backlight. Set the lighting so you can use f16, that's the magic aperture. Above f22 there are diffraction effects (not that you'd notice, they're somewhat theoretical) and below f16 you just lose valuable depth of field, which is only about a millimeter at close focus. It works well with full-frame cameras (D700, etc.) and APS-C cameras (D200, D300). It has a fairly unique mechanism for changing the spacing between items as you focus closer, instead of just moving the group. This maintains the flatness of the field and aperture, I believe anyway.
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