PK-R

**Buddha Jones** · 02-26-2008, 10:41 PM

Refresh my memory, is that the mount to avoid because of the sticking on the camera problem?

*Canada_Rockies* · 02-26-2008, 10:53 PM

Yes. You need to disable the pin that hits into a hole in the Pentax mount.

drabina · 02-27-2008, 05:12 AM

I have Sigma lens that's marked K-PR (do not know it that's the same as PK-R) and I can mount that lens on my Pentax DSLR with no problems.

Bakkasan · 02-27-2008, 07:03 AM

Heh first 24 hour nightmare with my sears Ricoh getting stuck on my100d. The stomach drop... ALL previous lenses blah blah... When you see that and you have a lens that works fine on your old pentax body, one does assume right?? A metal tape measure saved the day.

Lowell Goudge · 02-27-2008, 07:17 AM

Originally Posted by Buddha Jones

Refresh my memory, is that the mount to avoid because of the sticking on the camera problem?

I think you should read the attached link

The info you want is near the bottom
Pentax Lens/Camera Compatibility - Mark Roberts Photography

drabina · 02-27-2008, 08:43 AM

Now you guys got me scared. Could somebody clarify that my Sigma K-PR lens is compatible with my istDL DSLR? I have mounted it on the camera few times with no problems. If somebody could post picture of the PK-R mount with the visible pin that causes the problem, that would be great.

Thanks.

roscot · 02-27-2008, 09:22 AM

PK-R or K-PR or or any other version of the K mount refers to a Pentax/Ricoh derivative of the Pentax K mount. It a it has an extra pin at about the 4:30 position looking at the lens mount, right where the Pentax AF drive is. That pin sometimes gets stuck in the AF drive. The pin does nothing with the Pentax DSLR bodies, so it is safe and advisable to disable it before mounting it on your body.

drabina · 02-27-2008, 11:53 AM

Originally Posted by roscot

PK-R or K-PR or or any other version of the K mount refers to a Pentax/Ricoh derivative of the Pentax K mount. It a it has an extra pin at about the 4:30 position looking at the lens mount, right where the Pentax AF drive is. That pin sometimes gets stuck in the AF drive. The pin does nothing with the Pentax DSLR bodies, so it is safe and advisable to disable it before mounting it on your body.

Thanks roscot. I will check my lens to make sure the pin is not there before I mount the lens on the body again.

bigben91682 · 02-27-2008, 07:05 PM

I had this happen to me when I first changed over to Pentax. After reading up on various removal techniques I went out and bought a feeler gauge but couldn't for the life of me get under the pin enough to remove the lens. I got so frustrated that I just started sawing the pin, while the lens was still mounted to the camera, with the feeler gauge. Luckily the pin was a very soft metal and I was able to cut through it in about 45 seconds of sawing...there were some little metal shavings stuck to the lens mount ring, but I was able to avoid getting anything on the sensor. The camera itself was unscathed, and I later removed the pin on the lens.

It was a miserable couple of hours trying to resolve that little doozy....but the "curcumcised" lens now works great, happy ending! WEEE

drabina · 02-27-2008, 07:24 PM

I have checked my KPR lens and I do see a pin at about 4:30. The pin is very small though. Plus there is another pin at about 6:00 position that is bigger than the 4:30 pin. I can remove the 4:30 pin but I want to make sure I am not removing an actual contact. This lens has the A setting so I assume that some of the contacts are for the aperture information being sent to the camera.

Attached is the picture with pins circled.
picture

Thanks.

Lowell Goudge · 02-27-2008, 07:46 PM

Originally Posted by drabina

I have checked my KPR lens and I do see a pin at about 4:30. The pin is very small though. Plus there is another pin at about 6:00 position that is bigger than the 4:30 pin. I can remove the 4:30 pin but I want to make sure I am not removing an actual contact. This lens has the A setting so I assume that some of the contacts are for the aperture information being sent to the camera.

Attached is the picture with pins circled.
picture

Thanks.

the pin you show at 4:30 is actually the A settingpin. there are 6 pins and contact spots, starting clockwise about 1/4 inch from the lens locking slot. these are the apature information and A mode selection, the pin at 6:00 is the one you want/

You can remove it by unscrewqing the lens mount carefully (so the other pins don't get lost) or possibly cut it off. I don't own any K-PR lenses so I have never ddone this, but I have converted a K mount to KA mount, so I know th e pentax pin / contact locations. If you want to be sure. look at your camera body mount, and the orientation fo contacts away from the lens locking pin

drabina · 02-27-2008, 08:51 PM

Lowell Goudge, I think you are right. When I have compared my FA lens the 4:30 pin is same on both lenses so it cannot cause the locking problem. Now the 6:00 pin goes right thru the AF drive pin.

Now in my lens, the 6:00 pin is less than 0.5mm (1/32"?) above the mount. Do you think it could still cause the problem and the lens could lock on the camera? I have mounted the lens on my istDL few times and it came off with no problems. That was before I knew about the locking pin. Now I simply got scared because I do not want to use hacksaw to get the lens off next time it does not come off.

Lowell Goudge · 02-28-2008, 06:07 AM

Originally Posted by drabina

Lowell Goudge, I think you are right. When I have compared my FA lens the 4:30 pin is same on both lenses so it cannot cause the locking problem. Now the 6:00 pin goes right thru the AF drive pin.

Now in my lens, the 6:00 pin is less than 0.5mm (1/32"?) above the mount. Do you think it could still cause the problem and the lens could lock on the camera? I have mounted the lens on my istDL few times and it came off with no problems. That was before I knew about the locking pin. Now I simply got scared because I do not want to use hacksaw to get the lens off next time it does not come off.

I can't honestly say what the risk is.

Some people have in the past reported that if you put the body in AF and let the focusing screw turn, sometimes the pin is pushed back. But as I stated earlier, I have never owned one of these lenses so I just DON'T KNOW.

If it was my lens and having taken lens mounts off in the past and done lens conversions, I would not be afraid to take th emount off and remove the pin properly (so that I could restore the lens if someone wanted it). But again, that is me, I don't know if you have the confidence or the desire to take the lens partially apart.

I do know I would do something if I want to mount the lens, because the perceived risk is too high of getting it stuck.

drabina · 02-28-2008, 02:20 PM

I have found guide with pictures on how to remove the pin. Will attempt the procedure tonight. Hopefully I will not mess up the lens.

drabina · 02-28-2008, 07:29 PM

Well, I followed the instructions and removed the pin. I had an extra piece of plastic so the pin was sandwitched between this plastic and metal mount. Anyway, I got the pin out, reassembled the lens and now when I mount it on the camera (istDL) the aperture on LCD display just shows two dashes (--). I guess the pin was doing something else then just sitting there waiting to be jammed in the AF drive.

Any suggestions?