Oddball Lens Mounts

[br1078lum]

Got my latest goodies package from eBay today.  There were 48 items all total, and some of them were a bit odd to say the least. 

Of the many lens mount adapters, there were two that were M42-to-(and here is where the strange part comes in) CS and MA.  I looked up different mounts, and found a wonderful listing on Wikipedia (much better than the one on Camerapedia), and it was repeated on Lens Reviews in a clearer fashion.  According to the listing, a CS mount is basically the same as the cine C mount, only with a 5mm shorter flange-to-film distance, and is used in industrial and scientific instruments.  Only problem is, that is a 32mm mount, and this is 42mm, although the thread pitch is different than M42.

The MA wasn't listed at all, and it is a 44mm thread size, with about the same pitch as the M42-to-CS mount.

Has anybody ever encountered these mounts?  Neither of the adapters had manufacture names on them, but they matched the style of the one that was in a plain blue box, and was M42-to-NIF, with 'Made In Japan' on all three of them.

PF

[Glenn Thoreson]

44mm is Miranda, if my brain still works. What are these things? they sound like T-mount adapters. ? :confused:

[LarryD]

Mamaya also had 2 different lens mounts and both had adapters to fit Screw and K mount.

 But I think Glen is right in the MA.

 As for the other ones they are T- mounts.

[r-brian]

The Mamiya NC1000 slr lenses were identified as a Mamiya CS bayonet mount.  It was an unique mount for the NC1000, NC1000S and Sears equivalent.

[br1078lum]

After looking at all the replies, and studying the matter a bit further, I realized these are T2 adapters, which if I am correct, has a different flange-to-film distance than an M42 to accomodate the adapter.  Where I got mixed up is the M42 and T2 threads are identical (saves on tooling costs), and when you mount an M42 lens it will affect the infinity focus due to the 3mm increase in flange distance.

I was thinking like Glenn as far as the MA standing for Miranda.  And the Mamiya CS makes all the sense in the world too, r-brian, except that these are screw mounts.  I thought maybe it would stand for Canon S, but that was a 39mm screw.  So, I'll have to keep researching what the CS mount is.  The thread pitch does allow it to screw into the T2 end of the mount, so that is probably not different from M42, so maybe the CS stands for 'Common Size'.  I'll have to try it out on one of my Ricohs.

Thanks for all the help, and I'll post here if I get it figured out.

PF

[br1078lum]

Okay, after further review...

What I have learned is that the M42 and T2 threads are the same size, but not the same pitch.  M42 has a 1mm pitch, while the T2 is .75mm, thus they are uninterchangable, and will damage the lens/camera when so doing.  Good thing I didn't give it a good twist.

The CS mount stands for 'Contax S', which Zeiss started, and is the originator of all M42's.  When Pentax cameras became popular in the US, it started being called 'Pentax Screw', though they had nothing to do with developing it.  Later, when it was adapted by many more companies, it became known as 'Universal Screw', with further modifications to include automatic operation of the diaphram.

So my adapters are T-mounts for Miranda and M42, and I also wound up with two more for Nikon and Pentax K.  And I don't even own a T-mount lens.  Guess I need to start looking.  Those big old 400mm to 1200mm presets are looking pretty good right now.

Once again, thanks for all the help, sometimes that is all that is needed to get one going in the right direction.

PF