Mamiya 135 2.8 M42 Mounting Question (NON-SX)

godwinaustin · 03-13-2013, 09:56 PM

Hi,

Bought my first M42 Lens and it is a Mamiya Sekor 135 2.8. It has the A/M switch to switch to manual and is NOT the SX version.

I am confused as to whether this lens can get stuck on newer bodies such as my K30 or if it is just the SX version of this lens that has mounting issues on pentax bodies.

Thanks!

stevebrot · 03-13-2013, 11:19 PM

Originally posted by godwinaustin

Hi,

Bought my first M42 Lens and it is a Mamiya Sekor 135 2.8. It has the A/M switch to switch to manual and is NOT the SX version.

I am confused as to whether this lens can get stuck on newer bodies such as my K30 or if it is just the SX version of this lens that has mounting issues on pentax bodies.

Thanks!

Should work fine. Put the adapter on the lens first. That should give you a clue as to whether there are any issues. The mounting problem with the SX lenses is not so much that they get stuck as that they may not mount cleanly due to a "wrap-around" aperture ring that snugs up prematurely to the body flange on a K-mount camera. The result is a non-functional aperture ring and loss of infinity focus. There is a similar issue with some Helios 44-3 58/2 variants.

For the record, there are very few M42 lenses that have mounting issues on K-mount cameras. The most common problems are:

No A/M switch
Wrap around focus or aperture rings. (Some vintage M42 bodies features a very petite body flange paired with matching lenses that neatly hid the mount.)
Large lens bodies that interfere with built-in flash housings (think fat mirror lenses)
M42 bellows suffering from the same problem
Proprietary mount features that physically interfere with a clean mount to the adapter
Deep rear elements that interfere with mirror movement when adapted to Canon FF

Steve

vonBaloney · 03-13-2013, 11:24 PM

Some M/S's have a hard pin on the mount that needs to be removed -- that will cause it to get stuck or possible damage the camera side. And it isn't just those that say SX that have the overhanging aperture ring -- there are variants of the 135/2.8 that as far as I can tell are identical to the SX version except they don't say SX on them -- I've had both. (It could be the SX version has that hard pin and the non-SX doesn't. I sold my SX, but I seem to recall pulling a pin out of it? (I definitely pulled a pin out of my 28/28 SX as well as filed down the ring.) But I have a non-SX 135/2.8 sitting right in front of me now and it does have an overhanging aperture ring but no pin -- haven't gotten around to filing it down yet.

Oh, and you also have to glue or otherwise hold down the aperture pin as (many of them) don't have A/M switches, but yours does I guess. So several variants out there.

godwinaustin · 03-14-2013, 10:08 PM

Originally posted by vonBaloney

Some M/S's have a hard pin on the mount that needs to be removed -- that will cause it to get stuck or possible damage the camera side. And it isn't just those that say SX that have the overhanging aperture ring -- there are variants of the 135/2.8 that as far as I can tell are identical to the SX version except they don't say SX on them -- I've had both. (It could be the SX version has that hard pin and the non-SX doesn't. I sold my SX, but I seem to recall pulling a pin out of it? (I definitely pulled a pin out of my 28/28 SX as well as filed down the ring.) But I have a non-SX 135/2.8 sitting right in front of me now and it does have an overhanging aperture ring but no pin -- haven't gotten around to filing it down yet.

Oh, and you also have to glue or otherwise hold down the aperture pin as (many of them) don't have A/M switches, but yours does I guess. So several variants out there.

thank you for the replies.

von, when you say a "hard pin" what do you mean?

there is a pin on the lens but it pushes in with pressure and back out when released. no aperture ring on this model.

vonBaloney · 03-14-2013, 10:19 PM

Originally posted by godwinaustin

thank you for the replies.

von, when you say a "hard pin" what do you mean?

there is a pin on the lens but it pushes in with pressure and back out when released. no aperture ring on this model.

Yeah, that's the aperture pin and is found on most m42s. This other pin, if it were there, would be on the base of the mount -- the part the ends up snug against the mount on the body. So if there were a hard pin sticking out of that, it would scrape across your electrical contacts and possibly make the lens get stuck when it hit the slot of the lens release button. You'd see it if it were there.

03-13-2013, 09:56 PM	#1
godwinaustin Forum Member Join Date: Dec 2012 Location: Jackson, Wyoming Posts: 89	Mamiya 135 2.8 M42 Mounting Question (NON-SX) Hi, Bought my first M42 Lens and it is a Mamiya Sekor 135 2.8. It has the A/M switch to switch to manual and is NOT the SX version. I am confused as to whether this lens can get stuck on newer bodies such as my K30 or if it is just the SX version of this lens that has mounting issues on pentax bodies. Thanks!

03-13-2013, 11:19 PM	#2
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by godwinaustin Hi, Bought my first M42 Lens and it is a Mamiya Sekor 135 2.8. It has the A/M switch to switch to manual and is NOT the SX version. I am confused as to whether this lens can get stuck on newer bodies such as my K30 or if it is just the SX version of this lens that has mounting issues on pentax bodies. Thanks! Should work fine. Put the adapter on the lens first. That should give you a clue as to whether there are any issues. The mounting problem with the SX lenses is not so much that they get stuck as that they may not mount cleanly due to a "wrap-around" aperture ring that snugs up prematurely to the body flange on a K-mount camera. The result is a non-functional aperture ring and loss of infinity focus. There is a similar issue with some Helios 44-3 58/2 variants. For the record, there are very few M42 lenses that have mounting issues on K-mount cameras. The most common problems are: No A/M switch Wrap around focus or aperture rings. (Some vintage M42 bodies features a very petite body flange paired with matching lenses that neatly hid the mount.) Large lens bodies that interfere with built-in flash housings (think fat mirror lenses) M42 bellows suffering from the same problem Proprietary mount features that physically interfere with a clean mount to the adapter Deep rear elements that interfere with mirror movement when adapted to Canon FF Steve

03-13-2013, 11:24 PM	#3
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Some M/S's have a hard pin on the mount that needs to be removed -- that will cause it to get stuck or possible damage the camera side. And it isn't just those that say SX that have the overhanging aperture ring -- there are variants of the 135/2.8 that as far as I can tell are identical to the SX version except they don't say SX on them -- I've had both. (It could be the SX version has that hard pin and the non-SX doesn't. I sold my SX, but I seem to recall pulling a pin out of it? (I definitely pulled a pin out of my 28/28 SX as well as filed down the ring.) But I have a non-SX 135/2.8 sitting right in front of me now and it does have an overhanging aperture ring but no pin -- haven't gotten around to filing it down yet. Oh, and you also have to glue or otherwise hold down the aperture pin as (many of them) don't have A/M switches, but yours does I guess. So several variants out there. Last edited by vonBaloney; 03-14-2013 at 10:21 AM.

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03-14-2013, 10:08 PM	#4
godwinaustin Forum Member Join Date: Dec 2012 Location: Jackson, Wyoming Posts: 89 Original Poster	Originally posted by vonBaloney Some M/S's have a hard pin on the mount that needs to be removed -- that will cause it to get stuck or possible damage the camera side. And it isn't just those that say SX that have the overhanging aperture ring -- there are variants of the 135/2.8 that as far as I can tell are identical to the SX version except they don't say SX on them -- I've had both. (It could be the SX version has that hard pin and the non-SX doesn't. I sold my SX, but I seem to recall pulling a pin out of it? (I definitely pulled a pin out of my 28/28 SX as well as filed down the ring.) But I have a non-SX 135/2.8 sitting right in front of me now and it does have an overhanging aperture ring but no pin -- haven't gotten around to filing it down yet. Oh, and you also have to glue or otherwise hold down the aperture pin as (many of them) don't have A/M switches, but yours does I guess. So several variants out there. thank you for the replies. von, when you say a "hard pin" what do you mean? there is a pin on the lens but it pushes in with pressure and back out when released. no aperture ring on this model.

03-14-2013, 10:19 PM	#5
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by godwinaustin thank you for the replies. von, when you say a "hard pin" what do you mean? there is a pin on the lens but it pushes in with pressure and back out when released. no aperture ring on this model. Yeah, that's the aperture pin and is found on most m42s. This other pin, if it were there, would be on the base of the mount -- the part the ends up snug against the mount on the body. So if there were a hard pin sticking out of that, it would scrape across your electrical contacts and possibly make the lens get stuck when it hit the slot of the lens release button. You'd see it if it were there.