Bessaflex TM: Super-Takumar 50/1.4 touches the mirror

jochen said:

Hello,
there are different 1:1,4/50 mm Super-Takumar types. The first had 8 lenses, all later type had 7. Even though all have M 42 thread mount, not all of them can be used with any camera with M42 thread mount. Especially the 8-lenses Type could make problems. The reasons are 1) the protruding rear lens and 2) with some very old M 42 cameras (maybe your Bessaflex) the pin for activating the automatic diaphragm of the lens. Even with the 7 lens Super-Takumars and Super-Multi-Coated Takumars there were dfferences. In the manuals for the Spotmatic and until the ES II and for the lenses there are warnings which lenses cannot be used with specific camera bodies.
All 50 mm lenses for 35 mm SLRs are retrofocus designs and in these early days the designers had problems to calculate high-speed lenses with an adequate distance from the film plane for a given register distance. In fact most had a little more than 50 mm focal length and some had 55 or even 58 mm (Noct Nikkor, Rokkor). By far more difficult was the design of wide angle lenses for SLRs with an automatic flipping mirror.

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John Koehrer said:

What he said^^^But at the same time I'm surprised that the rear element protrudes that far enough to hit the mirror.
I'll assume that the lens is not going past infinity.

Try it on another body if you can. If the lens was worked on in the past and the helix was assembled wrong that could happen. Actually if the lens was apart and the helical was started one thread off it would be possible to never reach infinity.

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jochen said:

All 50 mm lenses for 35 mm SLRs are retrofocus designs and in these early days the designers had problems to calculate high-speed lenses with an adequate distance from the film plane for a given register distance. In fact most had a little more than 50 mm focal length and some had 55 or even 58 mm (Noct Nikkor, Rokkor). By far more difficult was the design of wide angle lenses for SLRs with an automatic flipping mirror.

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Fixcinater said:

The M42 Biotar 58/2.0 also protrudes into the mirror box enough to stop the mirror on some cameras.

Probably nothing wrong with your camera. It is a fairly well known problem on M42 bodies with certain lenses.

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aoresteen said:

The Super Takumar 50mm f/1.4 has always been a problematic lens since it was introduced in 1964 due to the rear element protruding into the camera body. From the Pentax Spotmatic manual:

"Do not use the new Super-Takumar 50mm f 1.4 lens with any other camera or any other Honeywell Pentax model except with models H3v and H1a, having orange-colored "R" marking on the film rewind knob, or you will damage the rear element of the lens"

http://www.butkus.org/chinon/pentax/pentax_spotmatic/pentax_spotmatic-2.htm

The problem only affects the early version of the Super Takumar 50/1.4 with early Pentax cameras, while its late version and the Super Multicoated 50mm f/1.4 are safe with Pentax early cameras. All versions of the Spotmatic (SP, SL, SPII, 1000, 500, F, ES, ESII) are safe with any Takumar 50/1.4 (either ST or SMCT). The problem only affects the older Super Takumar 50/1.4 and the Pentax S1a/H1a and the Pentax SV/H3v.

That is for PENTAX brand cameras.

For non-Pentax m42 cameras, any Super or Super Multi Coated Takumar 50mm f/1.4 can cause damage! Back in the 70's most camera stores that sold Pentax had lists of other M42 cameras the Pentax 50mm F/1.4 was safe with. You can put tape on the back of the lens to prevent the lens from protruding too deeply into the Bessaflex so it doesn't hit the mirror but infinity focus will be off. You'll have to stop down to get infinity elements sharp.

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John Koehrer said:

What he said^^^But at the same time I'm surprised that the rear element protrudes that far enough to hit the mirror.
I'll assume that the lens is not going past infinity.

Try it on another body if you can. If the lens was worked on in the past and the helix was assembled wrong that could happen. Actually if the lens was apart and the helical was started one thread off it would be possible to never reach infinity.

Click to expand...