I've bought some old lenses a while back (all M42 lens mounted lenses). I've decided to try and convert them to work on a Nikon Dslr, infinity focus and all. I succeeded on my first lens (first pictures), by replacing te mounting mechanism with a 3D printed one, it works flawless. It's awesome!

New mounting plate

However, I also have another lens, which I have high hopes for because it focusses beyond infinity when held up to my D3200. The problem is though, that I can't find a way for unmounting the mounting plate for replacement. I did try screwing off the side screws, it revealed a few philips head screws around the aperture ring, but I don't know if that's for the mounting plate or not... Anyone who has experience with the ones? Or is able to tell me if those screws are actually for the mounting plate?

Top view Side view 1 Side view 2

Thanks in advance!


  • What lens is that (manufacturer and specs)? Some lenses are serviced completely from the front. I find them to be a pain to work on and wouldn't bother if it's just to change the mount. I'd try to find an adapter, as Sowsun has suggested. – xiota Mar 25 '20 at 7:11
  • The lens is a Panagor PMC 135mm f2.8-22. If it's as you say and I need to do it all from the front I'll just sell it I guess. I've tried these adapters, but they are always too thick so infinity focus is nowhere to be found after adding it. – Wobbelaar Mar 25 '20 at 7:29
  • The lenses I've seen that are accessed from the front are all Asahi Pentax/Takumar. In one of the photos, I see some screws in front of the aperture ring that might give you access to the mount. But it would be a pain to work on, unless you especially like the image quality of that lens... – xiota Mar 25 '20 at 7:42
  • What software, printer, etc did you use to make the 3D print? How much does it cost to print a mount? – xiota Mar 25 '20 at 7:42
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    I'll keep you posted on my progress, I'll go buy a few screwdrivers this afternoon – Wobbelaar Mar 25 '20 at 8:21

I can't help you with disassembling that lens but since that lens will focus beyond infinity, I would either buy, or print yourself, a thin M42 to Nikon F adapter.

You can buy one like this for under $5.00

enter image description here

  • Thanks for the idea! 😁 However I've tried these adapters, but they are always too thick so infinity focus is nowhere to be found after adding it. So that's why I wanted to replace the mount. – Wobbelaar Mar 25 '20 at 7:30
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    The one in my photo is VERY thin. Have you tried one like that? – Mike Sowsun Mar 25 '20 at 11:07

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