The PN105 I purchased was modified to some weird M52 mount in a crude manner.
The seller was less than helpful, saying he doesn't know and refusing to ask the people that does such destruction... I mean adaption.
The M52 was neither x0.75, nor x1, nor SM2, I couldn't figure out what kind of thread depth it is. Don't care what it is. I want to throw this adapter away.
I measured about 48mm, compared the threads to an M38x0.5 adapter. It seems like M48x0.75?
Does anyone have any information? I appreciate the help!
PN105 had its original threading removed, cover cylinder removed, and converted via that crappy cheapo silver mount.
I think it's M48x0.75
Top: M38x0.5
Bottom: The crummy adapter
The thread pitch does look like x0.75 to me.
The Internal Mount of the PN 105mm f/2.8 "A Version&quo
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If you don't mind pulling a bit of metal off, I'd appreciate a check! It's not destructive, the seller told me the metal has been tossed away, way to destroy a lens, oh it focuses to infinity... hilarious...ray_parkhurst wrote:Only way to be sure is to measure it. Calipers for the thread diameter, and either use a ruler with fine scale for the pitch, or a male threaded adapter of the suspected pitch and see if the threads mate without gaps.
If you need I can check one of mine.
The 48mm-ish number was obtained from a low quality caliper, my Mitutoyo one ran out of battery, waiting for coin cells to arrive.
Pressing two threads to see a fit is great idea, I just gave that a go. Tried a filter x0.75 pitch adapter with a 52mm opening, pressed it against the threads and attempted to gently "pull" the adapter, couldn't do it. The threads do seem to match, so my M48x0.75 speculation might be accurate. I tried an m542x1 helicoid, a gentle pull makes the tube dismount very easily, heard the typical clunky sound of thread teeth grinding against each other.
I'd say it's safe to assume it's a 48mm x0.75 thread. I would probably get one from Raf before ordering a dedicated tube from a machinist.
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