Tilted Super Tak 50mm F1.4 lens on DSLR?

thephototruth · 05-25-2014, 12:03 PM

The adapter I purchased for my camera fit on perfectly except that the numbers for focusing and aperture are not directly at the top meaning the lens is kind of tilted to the right. Would this effect image quality in any way? Thanks!

**monochrome** · 05-25-2014, 01:29 PM

I believe that is quite common with the genuine Pentax adapters, at least the newer ones. It has not affected my IQ in any way.

johnyates · 05-25-2014, 04:31 PM

I like this 'feature' of the 3rd part adapters--you can easily see which aperture you have set as the overhanging 'nose' at the front of the camera is not obscuring your view.

thephototruth · 05-25-2014, 05:41 PM

Originally posted by monochrome

I believe that is quite common with the genuine Pentax adapters, at least the newer ones. It has not affected my IQ in any way.

Thanks! Monochrome. Haven't had too much experience with this lens so not sure if the image quality has been affected.

OregonJim · 05-25-2014, 05:56 PM

Originally posted by thephototruth

The adapter I purchased for my camera fit on perfectly except that the numbers for focusing and aperture are not directly at the top meaning the lens is kind of tilted to the right. Would this effect image quality in any way? Thanks!

It will not affect image quality. However, if you're off by more than half a turn or so, the lens may no longer focus all the way to infinity (as it will be too far from the film/sensor plane). If you're within a half-turn over or under, it should be fine.

**lmd91343** · 05-25-2014, 06:38 PM

That was considered a feature by some! Canon had the focus and f-stop indexes rotated by 30* as late as the late '60s. I have two cameras from '68 with that feature and three from earlier.

Perhaps it is designed that way. I have three non-Pentax and one Pentax brand adapters that work that way. Johnyates might be on to something.

**Lowell Goudge** · 05-25-2014, 10:03 PM

What you have discovered is part of the reason pentax switched to a bayonet mount shortly after introducing open aperture metering on some spotmatic models. Registration of the lens was critical to exposure accuracy

Some of my taks don't line up straight either , don't sweat it

stevebrot · 05-25-2014, 10:11 PM

It is also a "feature" of the lens as much as a feature of the adapter/body. NONE* of my M42 lenses line up on ANY of my M42 bodies and each lens lines up at a different point on a particular body. It is the same story with M39 Leica thread mount too.

Steve

* I take that back. My early, reverse direction, ST 55/1.8 registers properly on the Singlex TLS. Similarly, the Auto-Rikenon 50/1.7 from the Singlex registers properly on the SV. Go figure...

**lmd91343** · 05-25-2014, 10:26 PM

As I recall all of my Taks line-up near perfect on my Spot F. I'll check a few on Monday.

**lmd91343** · 05-26-2014, 08:17 AM

The 28, 50 macro, and 105 SMC Taks lined up within a degree or two of perfect alignment. They may have been perfect, they were too close to measure. My Super-Tak 24, was visibly off by as much as 5*. I did not try any other cameras or lenses. My only non-Pentax M42 is a Vivitar 90-180mm. I will that next time I dig it out and post the results.

It does appear that the offset on the adapter is designed, not accidental.

vonBaloney · 05-26-2014, 08:35 AM

Originally posted by OregonJim

It will not affect image quality. However, if you're off by more than half a turn or so, the lens may no longer focus all the way to infinity (as it will be too far from the film/sensor plane). If you're within a half-turn over or under, it should be fine.

I think they are still completely turned in and the registration distance is unaffected -- just the the threads are not positioned on the adapter so that it lines up straight when it is screwed in.

stevebrot · 05-26-2014, 09:25 AM

Originally posted by vonBaloney

I think they are still completely turned in and the registration distance is unaffected -- just the the threads are not positioned on the adapter so that it lines up straight when it is screwed in.

What he said. The registration distance on M42 lenses is determined by the mount face. It make no difference how the lens aligns to the body as long as the face mates to the mount flange on the body.

Another word in relation to the orientation of the lens to body and why they don't consistently match up...consider, if you would, how threads are cut and the nature of the M42 mount. First, the mount is not standardized. It is defined by convention. Second, it is amazing that the lenses line up as well as they do considering that it is not easy to define the point of entry for the thread even with the best dies and taps. Probably the best alignment would happen if the mounting holes are drilled after the threads are cut with the hole position determined by the cut of the thread.

As an aside, the best orientation match on my shelf is with my Vivitar 135/2.8 and one (not both) of my genuine Pentax M42 adapters. With that combination the alignment is good enough for the aperture display per the Judas windows on my K-mount film cameras. Cool, eh?

Steve

vonBaloney · 05-26-2014, 10:07 AM

I bought a batch of third-party adapters at a good price once (once I decide an m42 is going to be part of the my permanent stable I screw on third-party adapter on it [with the spring removed] so I can mount it bayonet-style easily). I was excited about the deal until they arrived and all the lenses ended up completely upside-down when screwed-in. Sent them back...

**pacerr** · 05-26-2014, 11:39 AM

Originally posted by vonBaloney

I was excited about the deal until they arrived and all the lenses ended up completely upside-down when screwed-in. Sent them back...

It's no problem to "shim" the adapter until the lens indexes where ever you want it to. I often use a thin rubber band between the adapter and lens base to achieve that 30-degree offset effect. So long as the lens base and camera mount mate normally registration distance is maintained.

tim60 · 05-27-2014, 03:48 AM

I have about 15 Taks. Some line up and a few do not. I do not believe it makes any difference to IQ.

I could not believe how they could make thread align so well over such a huge amount of production.

If the lens mount seats properly on the adapter the registration distance will be right.

05-25-2014, 12:03 PM	#1
thephototruth Inactive Account Join Date: May 2014 Posts: 3	Tilted Super Tak 50mm F1.4 lens on DSLR? The adapter I purchased for my camera fit on perfectly except that the numbers for focusing and aperture are not directly at the top meaning the lens is kind of tilted to the right. Would this effect image quality in any way? Thanks!

05-26-2014, 09:25 AM	#12
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by vonBaloney I think they are still completely turned in and the registration distance is unaffected -- just the the threads are not positioned on the adapter so that it lines up straight when it is screwed in. What he said. The registration distance on M42 lenses is determined by the mount face. It make no difference how the lens aligns to the body as long as the face mates to the mount flange on the body. Another word in relation to the orientation of the lens to body and why they don't consistently match up...consider, if you would, how threads are cut and the nature of the M42 mount. First, the mount is not standardized. It is defined by convention. Second, it is amazing that the lenses line up as well as they do considering that it is not easy to define the point of entry for the thread even with the best dies and taps. Probably the best alignment would happen if the mounting holes are drilled after the threads are cut with the hole position determined by the cut of the thread. As an aside, the best orientation match on my shelf is with my Vivitar 135/2.8 and one (not both) of my genuine Pentax M42 adapters. With that combination the alignment is good enough for the aperture display per the Judas windows on my K-mount film cameras. Cool, eh? Steve Last edited by stevebrot; 05-26-2014 at 09:32 AM.

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05-25-2014, 01:29 PM	#2
monochrome Loyal Site Supporter Join Date: Mar 2008 Location: Working From Home Photos: Gallery \| Albums Posts: 26,276	I believe that is quite common with the genuine Pentax adapters, at least the newer ones. It has not affected my IQ in any way.

05-25-2014, 04:31 PM	#3
johnyates Pentaxian Join Date: Aug 2011 Location: Saskatoon, SK Photos: Albums Posts: 1,345	I like this 'feature' of the 3rd part adapters--you can easily see which aperture you have set as the overhanging 'nose' at the front of the camera is not obscuring your view.

05-25-2014, 05:41 PM	#4
thephototruth Inactive Account Join Date: May 2014 Posts: 3 Original Poster	Originally posted by monochrome I believe that is quite common with the genuine Pentax adapters, at least the newer ones. It has not affected my IQ in any way. Thanks! Monochrome. Haven't had too much experience with this lens so not sure if the image quality has been affected.

05-25-2014, 05:56 PM	#5
OregonJim Veteran Member Join Date: Mar 2009 Location: Willamette Valley, Oregon Posts: 1,327	Originally posted by thephototruth The adapter I purchased for my camera fit on perfectly except that the numbers for focusing and aperture are not directly at the top meaning the lens is kind of tilted to the right. Would this effect image quality in any way? Thanks! It will not affect image quality. However, if you're off by more than half a turn or so, the lens may no longer focus all the way to infinity (as it will be too far from the film/sensor plane). If you're within a half-turn over or under, it should be fine.

05-25-2014, 06:38 PM	#6
lmd91343 Site Supporter Join Date: Jul 2009 Location: Los Angeles, CA USA Photos: Gallery \| Albums Posts: 1,027	That was considered a feature by some! Canon had the focus and f-stop indexes rotated by 30* as late as the late '60s. I have two cameras from '68 with that feature and three from earlier. Perhaps it is designed that way. I have three non-Pentax and one Pentax brand adapters that work that way. Johnyates might be on to something.

05-25-2014, 10:03 PM	#7
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,886	What you have discovered is part of the reason pentax switched to a bayonet mount shortly after introducing open aperture metering on some spotmatic models. Registration of the lens was critical to exposure accuracy Some of my taks don't line up straight either , don't sweat it

05-25-2014, 10:11 PM	#8
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	It is also a "feature" of the lens as much as a feature of the adapter/body. NONE* of my M42 lenses line up on ANY of my M42 bodies and each lens lines up at a different point on a particular body. It is the same story with M39 Leica thread mount too. Steve * I take that back. My early, reverse direction, ST 55/1.8 registers properly on the Singlex TLS. Similarly, the Auto-Rikenon 50/1.7 from the Singlex registers properly on the SV. Go figure...

05-25-2014, 10:26 PM	#9
lmd91343 Site Supporter Join Date: Jul 2009 Location: Los Angeles, CA USA Photos: Gallery \| Albums Posts: 1,027	As I recall all of my Taks line-up near perfect on my Spot F. I'll check a few on Monday.

05-26-2014, 08:17 AM	#10
lmd91343 Site Supporter Join Date: Jul 2009 Location: Los Angeles, CA USA Photos: Gallery \| Albums Posts: 1,027	The 28, 50 macro, and 105 SMC Taks lined up within a degree or two of perfect alignment. They may have been perfect, they were too close to measure. My Super-Tak 24, was visibly off by as much as 5*. I did not try any other cameras or lenses. My only non-Pentax M42 is a Vivitar 90-180mm. I will that next time I dig it out and post the results. It does appear that the offset on the adapter is designed, not accidental.

05-26-2014, 08:35 AM	#11
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by OregonJim It will not affect image quality. However, if you're off by more than half a turn or so, the lens may no longer focus all the way to infinity (as it will be too far from the film/sensor plane). If you're within a half-turn over or under, it should be fine. I think they are still completely turned in and the registration distance is unaffected -- just the the threads are not positioned on the adapter so that it lines up straight when it is screwed in.

05-26-2014, 10:07 AM	#13
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	I bought a batch of third-party adapters at a good price once (once I decide an m42 is going to be part of the my permanent stable I screw on third-party adapter on it [with the spring removed] so I can mount it bayonet-style easily). I was excited about the deal until they arrived and all the lenses ended up completely upside-down when screwed-in. Sent them back...

05-26-2014, 11:39 AM	#14
pacerr Loyal Site Supporter Join Date: Jan 2008 Location: Paris, TN Photos: Gallery \| Albums Posts: 3,349	Originally posted by vonBaloney I was excited about the deal until they arrived and all the lenses ended up completely upside-down when screwed-in. Sent them back... It's no problem to "shim" the adapter until the lens indexes where ever you want it to. I often use a thin rubber band between the adapter and lens base to achieve that 30-degree offset effect. So long as the lens base and camera mount mate normally registration distance is maintained.

05-27-2014, 03:48 AM	#15
tim60 Pentaxian Join Date: Apr 2011 Photos: Albums Posts: 8,743	I have about 15 Taks. Some line up and a few do not. I do not believe it makes any difference to IQ. I could not believe how they could make thread align so well over such a huge amount of production. If the lens mount seats properly on the adapter the registration distance will be right.