Chinese M42 adapter turns over

gtxSeries · 05-26-2017, 09:36 AM

Thanks!

The pin is perfectly aligned where it should be. So it's a problem with the thread. That and the fact that:

1) I can mount the adapter at least two ways. (as intended and upside down)

2) When screwed on the lens, the red dot should align with the red mark on the lens perfectly. It does however not. (see attachment)

Attached Images

View Picture EXIF

D1N0 · 05-26-2017, 09:43 AM

Are you sure you lined up the adapter with the red dot adjacent to the red dot on the mount? It should just look like on the mx. I had one of those adapters get stuck in the mount of the k10d. after that I removed the spring. It won't lock but with most lenses it is on tight enough not to be a problem.

gtxSeries · 05-26-2017, 09:59 AM

Originally posted by D1N0

Are you sure you lined up the adapter with the red dot adjacent to the red dot on the mount? It should just look like on the mx. I had one of those adapters get stuck in the mount of the k10d. after that I removed the spring. It won't lock but with most lenses it is on tight enough not to be a problem.

As I said, on that photo, I put it in incorrectly on purpose! When I align it with the red dot, like it should be, it goes in fine and looks good. Then I screw in the lens, tighten it then I hear I click and it turns over, but it shouldn't be able to! I end up with a lens upside down! Therefore I put in the adapter incorrectly (see image) and turned it all the way I could, until it clicked in. This way I can almost properly mount the lens. (turned a little bit to the left, still...) Surprisingly, when mounted incorrectly, it doesn't unmount like when it's mounted correctly. This is a crappy adapter I guess.

So one of you said that the DSLRKit version would work and mount correctly? If yes, then I may get my hands on one in time...

D1N0 · 05-26-2017, 10:03 AM

Originally posted by gtxSeries

When screwed on the lens, the red dot should align with the red mark on the lens perfectly. It does however not.

Mine doesn't either but it is on the other side of infinity from yours:
Original Pentax adapter:

Chinese knock off:

---------- Post added 26-05-17 at 19:12 ----------

Originally posted by gtxSeries

This is a crappy adapter I guess.

Yeah they probably got the rotation of the bayonet wrong.

gtxSeries · 05-26-2017, 10:28 AM

Interesting. Is that really a genuine Pentax one?!

D1N0 · 05-26-2017, 10:49 AM

Yup it came with an old K-1000 set I got that had several m42 lenses.
You can tell by the font type:

Older ones say ASAHI PENTAX

timw4mail · 05-26-2017, 11:02 AM

With Soviet lenses like the Helios, being up to 90 degrees off wouldn't surprise me. Generally, though, I would blame the adapter.

---------- Post added 05-26-17 at 02:07 PM ----------

Originally posted by gtxSeries

As I said, on that photo, I put it in incorrectly on purpose! When I align it with the red dot, like it should be, it goes in fine and looks good. Then I screw in the lens, tighten it then I hear I click and it turns over, but it shouldn't be able to! I end up with a lens upside down! Therefore I put in the adapter incorrectly (see image) and turned it all the way I could, until it clicked in. This way I can almost properly mount the lens. (turned a little bit to the left, still...) Surprisingly, when mounted incorrectly, it doesn't unmount like when it's mounted correctly. This is a crappy adapter I guess.

So one of you said that the DSLRKit version would work and mount correctly? If yes, then I may get my hands on one in time...

Yeah, it's been my experience that they align correctly. I would hesitate to use the clip, though, as they are difficult to remove.

stevebrot · 05-26-2017, 11:26 AM

Originally posted by gtxSeries

Thanks for all the answers!

I've meant a flangeless in reality.

I have one that sits in the mount.
Now I've been taking a few photos of the situation and it's really quite funny.
On the MX, the lens focuses to infinity and is usable perfectly, BUT it's center is far off from the camera's, meaning the lens is over rotated.

As you can see on the attached images, the adapter fits perfectly and mounts the lens as well, but incorrectly. (even though it's perfectly useable)

I also made a few shots of the K10D... I'll insert those in another post...

Over-rotation of the non-flanged knock-off adapters is a common flaw and is often accompanied by difficulty removing the adapter. The position of the adapter in the mount on your K10D is indeed about 50° past where it should have stopped. The position on your MX is proper. The spring catch that is supposed to engage the stop on the body is apparently improperly sized/placed for consistent fit. Whether this is "perfectly usable" is debatable.

Steve

gtxSeries · 05-26-2017, 11:32 AM

It works, at least. With the removal tool, it's not hard to remove either.
But I think I'll try another type in time. Until then, I'll manage with this. If I don't mount it improperly, it is pure hell, unusable. It makes the lens turn, with the bayonet or the screw, instead of the focusing ring. Therefore I'll mostly use this on the MX and if I need digital, I'll jusr mount the Helios upside down.

stevebrot · 05-26-2017, 11:54 AM

Originally posted by gtxSeries

1) I can mount the adapter at least two ways. (as intended and upside down)

Eeek!!! While mounting upside down is possible and usually difficult, removal is usually extremely difficult. I don't have the link, but there is a thread within the last year regarding extraction of such. If yours easily mounts and unmounts inverted, the tangs must be far from standard.

Originally posted by gtxSeries

2) When screwed on the lens, the red dot should align with the red mark on the lens perfectly. It does however not. (see attachment)

I have used M42 lenses since 1971 and currently own about 20 lenses in that mount. Only a few screw on with the index mark opposite the red dot when used with the genuine adapter. Strangely, none of those are Pentax.* My Helios 44M is about 10° shy of lining up and is fairly typical in that regard. The three lenses that do line up are all early 70s vintage Vivitar. Since registration is determined by the body flange, the nonalignment should not cause infinity focus issues.

Steve

* My Takumars line up fairly well to 12 o'clock on my Pentax M42 bodies, but disturbingly, how well they align varies by body/lens combination. There are some things that are best left unexplored.

stevebrot · 05-26-2017, 12:24 PM

Originally posted by timw4mail

fit snugly in the k-mount

A snug fit is the opposite of good fit. The genuine adapter is a loose fit by design. The intent is that the adapter will "snug" into the spring-loaded tangs on the body as the lens flange engages the body flange. This feature ensures proper registration distance for all lenses.

Originally posted by timw4mail

There should probably be a list of decent knockoff adapters...

That would be nice, but even well-known brand names such as "Bower" are often sourced from multiple manufacturers and suffer from variable quality. I had a Bower stuck on one of my film cameras. It took several hours of effort before it could be removed, even using the provided tool.

Originally posted by Supakatti

And the adapters, as far they are identical with original Pentax labelled, are safe to use.

I have yet to find one that is identical, though some are close. Most differ in tang size, tang ramp (fit way too tight), retension spring design, and/or machining of the tang ends. The last two characteristics have been implicated in the "stuck adapter syndrome", with the use of chamfered ends on all tang ends being the most likely culprit.

gtxSeries · 05-26-2017, 12:29 PM

Thanks Steve!

Mine unmounts fairly easily, even in the wrong position and it's not that hard to mount it either. If it would, I wouldn't dare screw around with it. (assuming I use the given removal tool)

timw4mail · 05-26-2017, 12:56 PM

Originally posted by stevebrot

A snug fit is the opposite of good fit. The genuine adapter is a loose fit by design. The intent is that the adapter will "snug" into the spring-loaded tangs on the body as the lens flange engages the body flange. This feature ensures proper registration distance for all lenses.

Could you explain this a bit more?

By snug, I meant that the adapter fits into the K-mount in a way similar to a native k-mount lens when rotated onto the body. Not that the adapter seems to be a tight fit on the k-mount.

stevebrot · 05-26-2017, 02:52 PM

Originally posted by timw4mail

Could you explain this a bit more?

By snug, I meant that the adapter fits into the K-mount in a way similar to a native k-mount lens when rotated onto the body. Not that the adapter seems to be a tight fit on the k-mount.

The genuine adapter fits loose in the mount such that the face (no lens attached) settles about 0.3mm below the body's mount flange and is not tensioned against the mount in any way. The adapter rotates into position with almost no resistance*. When latched in place, it may be lifted slightly with a fingertip, again with no resistance. When the lens is screwed into the mount, the lens flange contacts the body flange about 45° before the lens fully tightens against the spring-loaded tangs on the body side to secure both lens and adapter into the mount.

Until the lens snugs up, the genuine adapter is free to "rock" in the mount. This characteristic is problematic with some German and FSU lenses having a narrow mount flange. Those lenses may not engage the K-mount body flange with the result that the lens rocks side-to-side and may focus past infinity.

Steve

* On a "non-crippled" K-mount there is slight resistance as the aperture simulator tab is rotated as the adapter is put in place.

**WPRESTO** · 05-27-2017, 05:30 AM

Originally posted by gtxSeries

Shots of the lens on my K10D.

I put on the adapter the wrong way now, on purpose. Why? Because this way it clicks into place and I can only remove the adapter with the given tool. Therefore it doesn't over rotate. If I put it in aligned with the red dot, it turns over, because of the lack of aperture lever. Also funny is the fact that no matter which way I put the adapter on, the lens doesn't align in the center, but rather in either on the left or right... Quite funny, if you ask me.

So long as the rear surface of the lens fits tightly against the lens flange of the camera body, the lens should be correctly mounted for infinity focus. As shown by you, the lens with the aperture index off to the side rather than directly at the 12 o'clock position, is a consequence of where the threading begins = the M42 thread of the adapter is not correctly registered with the bayonet mount of the adapter. This may be cosmetically annoying, but it will not interfere with proper focusing of the lens.

05-26-2017, 11:26 AM	#23
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by gtxSeries Thanks for all the answers! I've meant a flangeless in reality. I have one that sits in the mount. Now I've been taking a few photos of the situation and it's really quite funny. On the MX, the lens focuses to infinity and is usable perfectly, BUT it's center is far off from the camera's, meaning the lens is over rotated. As you can see on the attached images, the adapter fits perfectly and mounts the lens as well, but incorrectly. (even though it's perfectly useable) I also made a few shots of the K10D... I'll insert those in another post... Over-rotation of the non-flanged knock-off adapters is a common flaw and is often accompanied by difficulty removing the adapter. The position of the adapter in the mount on your K10D is indeed about 50° past where it should have stopped. The position on your MX is proper. The spring catch that is supposed to engage the stop on the body is apparently improperly sized/placed for consistent fit. Whether this is "perfectly usable" is debatable. Steve Last edited by stevebrot; 05-26-2017 at 11:35 AM. Reason: Edited for accuracy and completeness

05-26-2017, 11:54 AM	#25
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by gtxSeries 1) I can mount the adapter at least two ways. (as intended and upside down) Eeek!!! While mounting upside down is possible and usually difficult, removal is usually extremely difficult. I don't have the link, but there is a thread within the last year regarding extraction of such. If yours easily mounts and unmounts inverted, the tangs must be far from standard. Originally posted by gtxSeries 2) When screwed on the lens, the red dot should align with the red mark on the lens perfectly. It does however not. (see attachment) I have used M42 lenses since 1971 and currently own about 20 lenses in that mount. Only a few screw on with the index mark opposite the red dot when used with the genuine adapter. Strangely, none of those are Pentax.* My Helios 44M is about 10° shy of lining up and is fairly typical in that regard. The three lenses that do line up are all early 70s vintage Vivitar. Since registration is determined by the body flange, the nonalignment should not cause infinity focus issues. Steve * My Takumars line up fairly well to 12 o'clock on my Pentax M42 bodies, but disturbingly, how well they align varies by body/lens combination. There are some things that are best left unexplored. Last edited by stevebrot; 05-26-2017 at 12:03 PM.

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05-26-2017, 09:43 AM	#17
D1N0 Pentaxian Join Date: May 2012 Location: --- Photos: Gallery Posts: 6,802	Are you sure you lined up the adapter with the red dot adjacent to the red dot on the mount? It should just look like on the mx. I had one of those adapters get stuck in the mount of the k10d. after that I removed the spring. It won't lock but with most lenses it is on tight enough not to be a problem.

05-26-2017, 09:59 AM	#18
gtxSeries Junior Member Join Date: Jun 2015 Location: Százhalombatta, Hungary Photos: Gallery \| Albums Posts: 37 Original Poster	Originally posted by D1N0 Are you sure you lined up the adapter with the red dot adjacent to the red dot on the mount? It should just look like on the mx. I had one of those adapters get stuck in the mount of the k10d. after that I removed the spring. It won't lock but with most lenses it is on tight enough not to be a problem. As I said, on that photo, I put it in incorrectly on purpose! When I align it with the red dot, like it should be, it goes in fine and looks good. Then I screw in the lens, tighten it then I hear I click and it turns over, but it shouldn't be able to! I end up with a lens upside down! Therefore I put in the adapter incorrectly (see image) and turned it all the way I could, until it clicked in. This way I can almost properly mount the lens. (turned a little bit to the left, still...) Surprisingly, when mounted incorrectly, it doesn't unmount like when it's mounted correctly. This is a crappy adapter I guess. So one of you said that the DSLRKit version would work and mount correctly? If yes, then I may get my hands on one in time...

05-26-2017, 10:03 AM	#19
D1N0 Pentaxian Join Date: May 2012 Location: --- Photos: Gallery Posts: 6,802	Originally posted by gtxSeries When screwed on the lens, the red dot should align with the red mark on the lens perfectly. It does however not. Mine doesn't either but it is on the other side of infinity from yours: Original Pentax adapter: Chinese knock off: ---------- Post added 26-05-17 at 19:12 ---------- Originally posted by gtxSeries This is a crappy adapter I guess. Yeah they probably got the rotation of the bayonet wrong.

05-26-2017, 10:28 AM	#20
gtxSeries Junior Member Join Date: Jun 2015 Location: Százhalombatta, Hungary Photos: Gallery \| Albums Posts: 37 Original Poster	Interesting. Is that really a genuine Pentax one?!

05-26-2017, 10:49 AM	#21
D1N0 Pentaxian Join Date: May 2012 Location: --- Photos: Gallery Posts: 6,802	Yup it came with an old K-1000 set I got that had several m42 lenses. You can tell by the font type: Older ones say ASAHI PENTAX

05-26-2017, 11:02 AM	#22
timw4mail Pentaxian Join Date: Apr 2017 Location: Driving a Mirage Photos: Gallery \| Albums Posts: 1,670	With Soviet lenses like the Helios, being up to 90 degrees off wouldn't surprise me. Generally, though, I would blame the adapter. ---------- Post added 05-26-17 at 02:07 PM ---------- Originally posted by gtxSeries As I said, on that photo, I put it in incorrectly on purpose! When I align it with the red dot, like it should be, it goes in fine and looks good. Then I screw in the lens, tighten it then I hear I click and it turns over, but it shouldn't be able to! I end up with a lens upside down! Therefore I put in the adapter incorrectly (see image) and turned it all the way I could, until it clicked in. This way I can almost properly mount the lens. (turned a little bit to the left, still...) Surprisingly, when mounted incorrectly, it doesn't unmount like when it's mounted correctly. This is a crappy adapter I guess. So one of you said that the DSLRKit version would work and mount correctly? If yes, then I may get my hands on one in time... Yeah, it's been my experience that they align correctly. I would hesitate to use the clip, though, as they are difficult to remove.

05-26-2017, 11:32 AM	#24
gtxSeries Junior Member Join Date: Jun 2015 Location: Százhalombatta, Hungary Photos: Gallery \| Albums Posts: 37 Original Poster	It works, at least. With the removal tool, it's not hard to remove either. But I think I'll try another type in time. Until then, I'll manage with this. If I don't mount it improperly, it is pure hell, unusable. It makes the lens turn, with the bayonet or the screw, instead of the focusing ring. Therefore I'll mostly use this on the MX and if I need digital, I'll jusr mount the Helios upside down.

05-26-2017, 12:24 PM	#26
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by timw4mail fit snugly in the k-mount A snug fit is the opposite of good fit. The genuine adapter is a loose fit by design. The intent is that the adapter will "snug" into the spring-loaded tangs on the body as the lens flange engages the body flange. This feature ensures proper registration distance for all lenses. Originally posted by timw4mail There should probably be a list of decent knockoff adapters... That would be nice, but even well-known brand names such as "Bower" are often sourced from multiple manufacturers and suffer from variable quality. I had a Bower stuck on one of my film cameras. It took several hours of effort before it could be removed, even using the provided tool. Originally posted by Supakatti And the adapters, as far they are identical with original Pentax labelled, are safe to use. I have yet to find one that is identical, though some are close. Most differ in tang size, tang ramp (fit way too tight), retension spring design, and/or machining of the tang ends. The last two characteristics have been implicated in the "stuck adapter syndrome", with the use of chamfered ends on all tang ends being the most likely culprit.

05-26-2017, 12:29 PM	#27
gtxSeries Junior Member Join Date: Jun 2015 Location: Százhalombatta, Hungary Photos: Gallery \| Albums Posts: 37 Original Poster	Thanks Steve! Mine unmounts fairly easily, even in the wrong position and it's not that hard to mount it either. If it would, I wouldn't dare screw around with it. (assuming I use the given removal tool)

05-26-2017, 12:56 PM	#28
timw4mail Pentaxian Join Date: Apr 2017 Location: Driving a Mirage Photos: Gallery \| Albums Posts: 1,670	Originally posted by stevebrot A snug fit is the opposite of good fit. The genuine adapter is a loose fit by design. The intent is that the adapter will "snug" into the spring-loaded tangs on the body as the lens flange engages the body flange. This feature ensures proper registration distance for all lenses. Could you explain this a bit more? By snug, I meant that the adapter fits into the K-mount in a way similar to a native k-mount lens when rotated onto the body. Not that the adapter seems to be a tight fit on the k-mount.

05-26-2017, 02:52 PM	#29
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by timw4mail Could you explain this a bit more? By snug, I meant that the adapter fits into the K-mount in a way similar to a native k-mount lens when rotated onto the body. Not that the adapter seems to be a tight fit on the k-mount. The genuine adapter fits loose in the mount such that the face (no lens attached) settles about 0.3mm below the body's mount flange and is not tensioned against the mount in any way. The adapter rotates into position with almost no resistance. When latched in place, it may be lifted slightly with a fingertip, again with no resistance. When the lens is screwed into the mount, the lens flange contacts the body flange about 45° before the lens fully tightens against the spring-loaded tangs on the body side to secure both lens and adapter into the mount. Until the lens snugs up, the genuine adapter is free to "rock" in the mount. This characteristic is problematic with some German and FSU lenses having a narrow mount flange. Those lenses may not engage the K-mount body flange with the result that the lens rocks side-to-side and may focus past infinity. Steve On a "non-crippled" K-mount there is slight resistance as the aperture simulator tab is rotated as the adapter is put in place.

05-27-2017, 05:30 AM	#30
WPRESTO Loyal Site Supporter Join Date: Aug 2010 Location: Massachusetts Photos: Gallery \| Albums Posts: 59,142	Originally posted by gtxSeries Shots of the lens on my K10D. I put on the adapter the wrong way now, on purpose. Why? Because this way it clicks into place and I can only remove the adapter with the given tool. Therefore it doesn't over rotate. If I put it in aligned with the red dot, it turns over, because of the lack of aperture lever. Also funny is the fact that no matter which way I put the adapter on, the lens doesn't align in the center, but rather in either on the left or right... Quite funny, if you ask me. So long as the rear surface of the lens fits tightly against the lens flange of the camera body, the lens should be correctly mounted for infinity focus. As shown by you, the lens with the aperture index off to the side rather than directly at the 12 o'clock position, is a consequence of where the threading begins = the M42 thread of the adapter is not correctly registered with the bayonet mount of the adapter. This may be cosmetically annoying, but it will not interfere with proper focusing of the lens.