Originally posted by xandos Can anyone tell me how to use newer lenses in reverse? I recently got a 21mm LTD which I'd like to use with my 200mm instead of my pentax-M 28mm/3.5 (that combination works great btw), but the lack of apperture ring doesnt help. Does anyone know any tricks to get the 21mm to keep a certain aperture when used in reverse?
I picked up one of these recently:
Pentax K AF Mount (PKAF) DSLR Lens to Nikon F Mount SLR Camera Body Adapter ? Fotodiox, Inc. USA
Its original purpose was to enable the mounting of PK mount lenses on Nikon F mount bodies. It has aperture adjustment capability for lenses without aperture rings, like your 21 LTD. I removed the optical elements designed to allow infinity focus in its intended use and mounted it on the forward facing lens mount of my reverse mounted 18-55 kit zoom. It works great for aperture control, much better than my previous solution of jamming something to keep the aperture tab open! It's a de-clicked ring that allows varying degrees of opening or closure. What aperture you've got is a matter of guesswork, but it does work to keep the aperture open at a fixed position.
Things are just starting to thaw out here, so I'll be using it soon for closeups of bugs and buds.
I'd be very curious to see your 21 LTD's results. I get quite pleasing results from a reversed kit lens, so the LTD would be better, I imagine.
Here are some shots I got using my Sigma 10-20 reversed, at 10mm. Please excuse the dirty sensor! Field of view here is about 4mm, so this is almost 6x. Your 21 reversed should give you nearly 3x.