Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
10-14-2011, 08:47 AM   #1
New Member

Join Date: Oct 2011
Location: Wisconsin
Posts: 12
Screw Mount lens to k1000 camera

I have a Rexagon f2.8 28mm fish-eye screw mount (m42) lens that I'd like to use on my K1000 camera.

What type of adapter do I need to make this work?

Some research I've done mentions how the aperture pin gets stuck on some brands of adapters. However this is
the only m42 screw mount lens that I have so leaving the adapter on it is an ok option for my use.

Please advise...

10-14-2011, 10:59 AM   #2
Veteran Member

Join Date: Mar 2011
Location: Eastern Kentucky
Posts: 416
Pentax makes an adapter that works.Some after market adapters loose some focus capabilities
10-14-2011, 11:41 AM   #3
Veteran Member
sterretje's Avatar

Join Date: Dec 2008
Location: Roodepoort, South Africa
Photos: Gallery | Albums
Posts: 3,534
the original pentax one
10-14-2011, 12:57 PM   #4

Join Date: Sep 2007
Location: Bay Village, Ohio USA
Posts: 1,047
What you're referring to is the "dreaded Ricoh pin". AFAIK, this only appears on some Ricoh-compatible bayonet-mount lenses. So, you don't have to worry about that with an M42 lens.

As others have pointed out, some M42-kmount adapters have a large flange that gets between the lens and camera and prevents the lens from focusing to infinity. That's okay, if you only want to shoot close-ups, but no good if you want landscapes. The proper adapter sits entirely inside the lens mount opening of the camera.

Some insist on only the genuine Pentax adapter, but these can be a little hard to find. I have a third-party adapter and I have never had any trouble with it. I have removed the spring that locks it into the mount from mine. I leave it on my Super-Takumar 50mm, f/1.4 lens, effectively turning it into a k-mount lens.

One issue with many third-party m42 lenses is that they lack an auto/manual switch for the aperture. Since the K1000 has no mechanism to push the aperture pin, you must be able to stop the lens down manually. As far as I know, all genuine Pentax lenses have such a switch. Many third-party lenses do not, which means you can only shoot with them wide-open. If your lens lacks the switch, you may be able to modify it or somehow jam the pin so that the aperture pin stays depressed.

In use, you must use stop-down metering, even though the K1000 is capable of open-aperture metering. This means you focus and compose your shot, stop the lens down to the working aperture and select the shutter speed that centers the needle of the meter, and then take the shot.

10-14-2011, 07:33 PM   #5
New Member

Join Date: Oct 2011
Location: Wisconsin
Posts: 12
Original Poster
THANK YOU! I was able to find an original Pentax k Mount adapter (ebay picture shows the Pentax name and Japan stamped into the metal ring) for $33.00
The seller said he has 2 of these brand new - well 1 now.
Thanks again for the help...

  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
adapter, camera, k1000, lens, m42, pentax help, photography, screw, screw mount lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: 4 K mount lenses and 1 M42 screw mount lens (US/CAN) alanjoke Sold Items 8 07-20-2011 06:05 AM
I have takamar screw mount lens and need advice shootreadyaim Pentax SLR Lens Discussion 2 01-24-2011 02:13 PM
Screw Mount lens on K100DSuper cyfly Pentax DSLR Discussion 5 08-30-2010 07:29 AM
[Afraid] Can't get my M42 screw mount lens off my K-x! tiny Pentax DSLR Discussion 11 10-28-2009 10:25 PM
What Screw-Mount Pentax Camera To Purchase?? baltochef920 Pentax Film SLR Discussion 10 07-20-2007 12:00 PM

All times are GMT -7. The time now is 08:12 PM. | See also:, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]