Blue -- NEX-5 & Schneider-Kreuznach 75mm f4 Enlarging Lens. Click for larger.
Removed this enlarging lens from its Yashica 50mm f1.9 lens barrel, and made it part of the focus helicoid system I made. Schneider enlarging lenses are some of the sharpest lenses I have used. They are still very cheap right now and they do work perfectly with the NEX system, even with 50mm focal length, they can focus to infinity with a thin focusing helicoid.
The 49mm, 52mm and 55mm reversing ring for NEX have arrived. These are made of aluminum but fit the NEX E-mount perfectly with no play at all. I am planing to replace the c-mount adapter I used for my helicoid with one of these reversing rings. The reason is that the opening of the c-mount adapter is very small and thus for some long lenses, you can actually see vignetting. Of cause, you can use these rings to mount lenses in reverse to give you macro capabilities with very high magnifications.