M42 to Pentax Adaptors and Infinity Focusing
Hello!
I just want to ask if anyone has any suggestions or experience with adapting M42 lenses to Pentax cameras and how to get around the inability to focus to infinity. I recently acquired an M42 mount 135mm lens some time ago and a Helios 44-2 just today. With the 135mm I noticed that I couldn't focus beyond about 5 or so meters from me but was able to achieve focus with a teleconverter thrown on interestingly. However with my Helios I can't focus beyond about a meter.
For the Helios I've seen two suggestions to fix infinity focusing, the main one of which requires using a lathe to remove material and reduce flange distance and while I know my way around a lathe I'm not sure how comfortable I'd be working on a lens. The other non-permanent modification which involves inserting a spacer ring to the rear element, though I've heard this mod may reduce optical quality. Another option I've seen are a specific type of M42 to Pentax adaptor which sits flush inside the camera without the protruding flange but reviews on their quality range from not sitting securely to getting near permanently stuck inside the camera.
I never really considered this before as I have no problems focusing to infinity with my 600mm mirror which is also an M42 mount lens. I suppose with the Helios it's not the end of the world since I probably won't need to focus to infinity too often but I'd like for it to have a bit more reach so to speak.
Has anyone else had experience with adapting and getting around this issue?
What does you adapter look like? Mine is a generic one that sits flush on the mount with nothing protruding. I wasn’t aware there was any other kind. This allowed for infinity focus, or at least very close to it. I’m not sure I ever shot infinity with my Helios 44-2, but I sure got farther than 5m and never had any problem with focus with any of my other lenses.
Quote from Snappy on June 17, 2021, 2:38 pmWhat does you adapter look like? Mine is a generic one that sits flush on the mount with nothing protruding. I wasn’t aware there was any other kind. This allowed for infinity focus, or at least very close to it. I’m not sure I ever shot infinity with my Helios 44-2, but I sure got farther than 5m and never had any problem with focus with any of my other lenses.
This is the kind that I currently have, it adds maybe 1mm to the flange, though today I've ordered the type that sits flush with the body and hoping for better results. Hopefully I don't get the issues of it getting stuck in the camera body like some reviews have mentioned.
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Quote from Herd on June 17, 2021, 3:05 pmQuote from Snappy on June 17, 2021, 2:38 pmWhat does you adapter look like? Mine is a generic one that sits flush on the mount with nothing protruding. I wasn’t aware there was any other kind. This allowed for infinity focus, or at least very close to it. I’m not sure I ever shot infinity with my Helios 44-2, but I sure got farther than 5m and never had any problem with focus with any of my other lenses.
This is the kind that I currently have, it adds maybe 1mm to the flange, though today I've ordered the type that sits flush with the body and hoping for better results. Hopefully I don't get the issues of it getting stuck in the camera body like some reviews have mentioned.
Okay, hopefully that's all it is. You wouldn't think 1mm would do that much, but having designed and 3d printed adapters of various sorts, it makes sense.
I've had times where it was harder to get out of the camera than others, but always been able to remove it. Some people remove the little spring tab that locks it in place , but I still have mine there and just had to work it a few times so that it doesn't spring out of place (what makes it get stuck I think). Now it works like a charm every time. I had a genuine adapter but sold it so I could help fund a lens. The cheap one worked well enough for me 🙂
Quote from Snappy on June 19, 2021, 12:44 amQuote from Herd on June 17, 2021, 3:05 pmQuote from Snappy on June 17, 2021, 2:38 pmWhat does you adapter look like? Mine is a generic one that sits flush on the mount with nothing protruding. I wasn’t aware there was any other kind. This allowed for infinity focus, or at least very close to it. I’m not sure I ever shot infinity with my Helios 44-2, but I sure got farther than 5m and never had any problem with focus with any of my other lenses.
This is the kind that I currently have, it adds maybe 1mm to the flange, though today I've ordered the type that sits flush with the body and hoping for better results. Hopefully I don't get the issues of it getting stuck in the camera body like some reviews have mentioned.
Okay, hopefully that's all it is. You wouldn't think 1mm would do that much, but having designed and 3d printed adapters of various sorts, it makes sense.
I've had times where it was harder to get out of the camera than others, but always been able to remove it. Some people remove the little spring tab that locks it in place , but I still have mine there and just had to work it a few times so that it doesn't spring out of place (what makes it get stuck I think). Now it works like a charm every time. I had a genuine adapter but sold it so I could help fund a lens. The cheap one worked well enough for me
Yeah the cheap one without flange arrived yesterday and is a huge improvement thankfully with the only trade-off of being tedious to remove if I want to switch away from my M42 lenses, but this is no big deal. Still doesn't quite reach infinity but honestly the 44-2 isn't a lens I think I'd use that for anyway haha but it is much nicer to have a bit more reach finally.
Quote from Herd on June 19, 2021, 1:25 pmQuote from Snappy on June 19, 2021, 12:44 amQuote from Herd on June 17, 2021, 3:05 pmQuote from Snappy on June 17, 2021, 2:38 pmWhat does you adapter look like? Mine is a generic one that sits flush on the mount with nothing protruding. I wasn’t aware there was any other kind. This allowed for infinity focus, or at least very close to it. I’m not sure I ever shot infinity with my Helios 44-2, but I sure got farther than 5m and never had any problem with focus with any of my other lenses.
This is the kind that I currently have, it adds maybe 1mm to the flange, though today I've ordered the type that sits flush with the body and hoping for better results. Hopefully I don't get the issues of it getting stuck in the camera body like some reviews have mentioned.
Okay, hopefully that's all it is. You wouldn't think 1mm would do that much, but having designed and 3d printed adapters of various sorts, it makes sense.
I've had times where it was harder to get out of the camera than others, but always been able to remove it. Some people remove the little spring tab that locks it in place , but I still have mine there and just had to work it a few times so that it doesn't spring out of place (what makes it get stuck I think). Now it works like a charm every time. I had a genuine adapter but sold it so I could help fund a lens. The cheap one worked well enough for me
Yeah the cheap one without flange arrived yesterday and is a huge improvement thankfully with the only trade-off of being tedious to remove if I want to switch away from my M42 lenses, but this is no big deal. Still doesn't quite reach infinity but honestly the 44-2 isn't a lens I think I'd use that for anyway haha but it is much nicer to have a bit more reach finally.
Nice. If I still had my Helios I would see if mine ever reached infinity either. It is possible I never shot it at infinity, so there you go. You're probably right. Lends itself to other types of photos 🙂
I've made an interesting discovery today.
Taken by pure curiosity I decided to open up my Helios to have a look inside of it and interestingly enough I found an object inside of it which from what I've been able to find is not part of the original lens. Where the optical element would usually separate from the focusing body of the lens there is normaly a spacer ring, and when I opened up my own lens I found not only the usual spacer ring but a second one made of brass which I've not been able to find mention of in any videos or discussions on the disassembly of the 44-2.
The brass ring itself is pretty rough so my guess is that someone who owned this lens before me fasioned it out and stuck it in as their own modification to the lens either I suppose to allow infinity focus on some other system or so they could get closer to their subjects. With this brass ring removed I'm now able to focus to infinity with the flangeless M42 to Pentax adaptor!
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Quote from Herd on July 3, 2021, 5:16 pmI've made an interesting discovery today.
Taken by pure curiosity I decided to open up my Helios to have a look inside of it and interestingly enough I found an object inside of it which from what I've been able to find is not part of the original lens. Where the optical element would usually separate from the focusing body of the lens there is normaly a spacer ring, and when I opened up my own lens I found not only the usual spacer ring but a second one made of brass which I've not been able to find mention of in any videos or discussions on the disassembly of the 44-2.
The brass ring itself is pretty rough so my guess is that someone who owned this lens before me fasioned it out and stuck it in as their own modification to the lens either I suppose to allow infinity focus on some other system or so they could get closer to their subjects. With this brass ring removed I'm now able to focus to infinity with the flangeless M42 to Pentax adaptor!
Fascinating! I wouldn't have thought to open it up to check. What would the possible use case of that be? To help it focus on something with a larger flange distance?
Quote from Snappy on July 3, 2021, 6:43 pmQuote from Herd on July 3, 2021, 5:16 pmI've made an interesting discovery today.
Taken by pure curiosity I decided to open up my Helios to have a look inside of it and interestingly enough I found an object inside of it which from what I've been able to find is not part of the original lens. Where the optical element would usually separate from the focusing body of the lens there is normaly a spacer ring, and when I opened up my own lens I found not only the usual spacer ring but a second one made of brass which I've not been able to find mention of in any videos or discussions on the disassembly of the 44-2.
The brass ring itself is pretty rough so my guess is that someone who owned this lens before me fasioned it out and stuck it in as their own modification to the lens either I suppose to allow infinity focus on some other system or so they could get closer to their subjects. With this brass ring removed I'm now able to focus to infinity with the flangeless M42 to Pentax adaptor!
Fascinating! I wouldn't have thought to open it up to check. What would the possible use case of that be? To help it focus on something with a larger flange distance?
I'm thinking that may be the case, otherwise it might have been added as a sort of spacer ring for macro shots if no extention tubes are on hand would be my next guess, it's an incredibly easy modification to make as the optical block and housing are just two pieces which screw together and there is a generous about of thread to allow for it.
Quote from Herd on July 3, 2021, 10:48 pmQuote from Snappy on July 3, 2021, 6:43 pmQuote from Herd on July 3, 2021, 5:16 pmI've made an interesting discovery today.
Taken by pure curiosity I decided to open up my Helios to have a look inside of it and interestingly enough I found an object inside of it which from what I've been able to find is not part of the original lens. Where the optical element would usually separate from the focusing body of the lens there is normaly a spacer ring, and when I opened up my own lens I found not only the usual spacer ring but a second one made of brass which I've not been able to find mention of in any videos or discussions on the disassembly of the 44-2.
The brass ring itself is pretty rough so my guess is that someone who owned this lens before me fasioned it out and stuck it in as their own modification to the lens either I suppose to allow infinity focus on some other system or so they could get closer to their subjects. With this brass ring removed I'm now able to focus to infinity with the flangeless M42 to Pentax adaptor!
Fascinating! I wouldn't have thought to open it up to check. What would the possible use case of that be? To help it focus on something with a larger flange distance?
I'm thinking that may be the case, otherwise it might have been added as a sort of spacer ring for macro shots if no extention tubes are on hand would be my next guess, it's an incredibly easy modification to make as the optical block and housing are just two pieces which screw together and there is a generous about of thread to allow for it.
Super neat. I know that some soviet lenses came from the factory calibrated to the camera bodies they were sold on, especially rangefinders like the Zorkis and FEDs. Perhaps this was the case with this lens, although I'm not sure if it would have been the case with an m42 SLR lens.
