If you have been trying to make your own lens with enlarging lenses, medium format lenses, and other oddball lenses, no doubt you have encounter the problem of getting it to focus, because these lenses do not have their own focusing helicoids. For some reason, focusing helicoids are ridiculously expensive, ranging from $120 to $300 or more, and those are just generic helicoids with M42 mounts. There are some M43 native mount helicoids, but are still very expensive. As of this writing, I found not NEX dedicated helicoids on the market, so I have decided to make my own.

What you need:

1. NEX to C-Mount adapter
2. Vivitar Macro Focusing Teleconverter.
3. Drill with 1/32" drill bit.
4. Philips Screw driver

I chose the NEX to C-Mount adapter as the mount to attach to the helicoid, because it's the thinnest mount for NEX. Too thick the mount will make some lenses unable to focus to infinity. The C-Mount also is the simplest mount, making it easy to drill holes.