1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

T2 Adapter, M42 Adapter, Whats the Difference?

Discussion in 'General Equipment Chat & Advice' started by Iloca, Feb 22, 2006.

  1. Iloca

    Iloca Well-Known Member


    can anyone tell me what the difference is between a T2 adapter and an M42 adapter.

    Thanks, Richard
  2. frank1

    frank1 Well-Known Member

    I think its a different thread size I'm sure I've got a t2 around somewhere and when I tried to put it on a m42 lens, it screwed on so far then stopped. I'd be interested to know what the t2 adapter is for
  3. Iloca

    Iloca Well-Known Member

    Hi Frank,

    funny you should say that, I tried a Praktica lens on an OM/T2, it screws on but not fully, would that be the only difference, a Praktica screw lens is M42 isn't it?

    The reason I ask is that I was looking at a set of bellows that I wanted to fit to a Nikon D70 using the Praktica lens, just wondered if I needed a Nikon/T2 or Nikon/M42 or if either would do.

    Thanks, Richard
  4. Benchista

    Benchista Which Tyler

    What exactly do you mean by "Praktica" lens? No lenses were ever actually made with that branding, although there were a few M42 lenses with the "Prakticar" brand (and an awful lot more Praktica Bayonet ones.

    Anyway, the pitch of the thread is different between T2 and M42, and they should not be confused or inter-mounted.

    As an aside on lenses for Pentacon-thread Prakticas, the Electric versions won't mount on all cameras, as the electrical contacts can foul the screw holes in the mount. Less of an issue with mount convertors, though, and no problem with any Praktica.
  5. El_Sid

    El_Sid Well-Known Member

    You'd need a set of bellows with a Nikon mount at the body end and an M42 thread on the lens end. I have no idea whether such an animal exists but apparently SRB Film Services can modify bellows to suit (see page 4 of the adapter price list).

    As Nick says M42/T2 use different thread pitches so are not compatible.
  6. El_Sid

    El_Sid Well-Known Member

    The T2 mount is commonly found in astrophotography where it is used to mount the camera to the telescope in place of the eyepiece. It also used to be quite popular in the days of manual focus when there were a lot of cheap, usually preset, long lenses around which used the T2 mount and adapter. I presume it gave a cost effective way of offering the lenses in various OEM mounts without actually having to make the lenses in the specified mount.
  7. Iloca

    Iloca Well-Known Member

    Nick and Nigel,

    the lens is a Pentacon screw fit, thats an M42 isn't it? you say that theres a pitch difference, that would explain why the T2 screws on a bit. I sort of wondered if they were the same but named differently but obviously not.

    The bellows are Paragon so I'll need to check what fitting they are, do you have any idea? I'm guessing that they'll be M42. In any case am I right in saying that I'll need a body (Nikon)to screw M42/T2) adapter to fit the camera to the bellows and then the Pentacon lens should fit directly to the bellows, assuming they (bellows) are M42.

    Thinking out loud, I need to establish the fitting of the bellows first, e.g. M42 then all I need are adapters, say Nikon Body/M42 and say M42/ Nikon F to use a Nikon body and Lens or OM/M42 and M42/OM to use an Olympus Body and Lens. (Or whatever combination)

    Sorry if that sounds a bit confused, I know what I'm trying to say but can't quite put it in words :D :D

    Thanks Again, Richard
  8. El_Sid

    El_Sid Well-Known Member

    Yes, the lens is an M42. To the best of my knowledge all Pentacon screw lenses are M42.

    If the the bellows are threaded then I imagine they are M42, I don't recall ever coming across bellow with T2 mounts.

    If the bellows are M42 then the lens will fit directly to the bellows but you will still need the relevant lens to body adapter (eg M42 to Nikon) to mount the bellows or lens to the camera. SRB's adapter list (page 4) lists M42 adapters for both body types. Both these adapters contain lenses to maintain infinity focus when the lens is mounted directly to the camera. This is because either the camera mount throat is to small to allow the adapter to fit flush and/or the mount to film distance is more or less identical for the Nikon, Olympus and M42 systems.

    Hope this clarifies things a bit.....
  9. Iloca

    Iloca Well-Known Member

    Thanks Nigel,

    that all makes sense and confirms more or less what I was thinking. If I understand correctly, an adapter to fit M42 lenses to a Nikon needs an element to achive Infinity focus due to the differences in Flange to film plane, now if I was to use the adapter only to mount the camera to bellows, I'm thinking that I don't need to achive inf' focus so a plain mount would work, such as this.


    What do you think? Richard
  10. El_Sid

    El_Sid Well-Known Member

    For use only with bellows or extension tubes then yes a plain mount such as that is fine as the bellows or tubes have already eliminated distance focussing anyway.

  11. Iloca

    Iloca Well-Known Member

    Hi Folks,

    Well I got the bellows, turns out that it's a slide copier/bellows combined set by Paragon. The mounts on each end of the bellows are unthreaded but an adapter threaded for T2 fits in . It's a strange set-up due to the whole thing being modular. It came with a T2 adapter to suit the Nikon body, and the Pentacon (Praktica) lens screws on to the T2 thread at the other end enough to be secure, (part of the duplicator tube unscrews to use as a Macro lens)All in all it seems useable enough for the £20 odd it cost.

    Thanks to all for the help/advice,

    Cheers, Richard
  12. whs2001

    whs2001 New Member

    Funny, but with all of the posts here, nobody actually answered the actual question, which requires the actual specifications. A T2 or T-mount or T-thread has a width of 42mm with a thread pitch of 0.75mm. An M42 is also 42mm, but with a 1mm thread pitch. DON'T try to intermix the two or you will likely strip the threads on one, the other or both of the things you are trying to force together.
    -- Willy with a whY?™ (aka: The Prophet Willy™)
  13. Benchista

    Benchista Which Tyler

    Well it might have added very slightly to the info had you posted it at the time, but eight years later it's not a lot of help, especially as the OP hasn't been back here in over five years...
  14. frank1

    frank1 Well-Known Member

    It also makes me feel old.
  15. rboerdijk

    rboerdijk New Member

    I respectfully disagree, the information given by whs2001 is really useful. Google for "T2 vs M42" and this is the #1 hit.
    so even if the OP didn't react, many people will still find this info and can learn from it.
  16. Benchista

    Benchista Which Tyler

    And you think that's worth adding two years later still? ;)
  17. rboerdijk

    rboerdijk New Member

    I most certainly do, considering I took the effort of registering because of that :D
  18. RogerMac

    RogerMac Well-Known Member

    Well it's nice to see Iloca's byline appearing on the list of OPs again - even if he now does inhabit other forums.

Share This Page