Auto Mamiya/Sekor 50mm F/2 Depth of Field indicator misaligned?

I don't have much experience with classic film cameras, but I found a Mayima 500 DTL at a thrift shop a while ago, and thought it might be fun to shoot some film.

 

I was getting it ready for an upcoming trip when I noticed something odd. In the attached picture, I've turned the aperture ring as far as I could, but the "16" marker doesn't reach the "2" in the DOF indictaor. If I turn it the other direction, it the aperture ring goes past the point where I would expect it to stop.

 

In the second picture, you can see the two screw holes (one in the aperture ring) that are not aligned. In every other picture I've seen of this lens, those screws are aligned.

 

I'm thinking that the DOF indicator has been rotated in some way. Has anyone seen an issue like this?

 

Am I inviting disaster by attempting to disassemble and re-align these sections of the lens?

 

Thanks!

 

 

Hi, I see that infinity on the focusing ring is well past the index mark, where it should stop. Does it appear to focus past infinity on the camera?

 

I once had a Mamiya/Sekor SX 55/1.8 standard lens that did this, and initially I thought it was a problem with the lens, but it turned out to be that the focusing ring had slipped. On that lens, the ring was held in place by 3 screws inside (a pretty common arrangement). By removing the front of the lens housing, I was able to loosen the three screws, re-adjust infinity focus on camera, reset the ring at the infinity mark and then re-tighten the screws.

 

Not sure if that is all the problem with your lens, but it might be part of it.

Edited June 21, 2018 by m42dave

Hi, I see that infinity on the focusing ring is well past the index mark, where it should stop. Does it appear to focus past infinity on the camera?

 

It does not appear to focus past infinity. That's the thing...infinity on the focusing ring and the stopping point of the aperture ring seem to line up. In that first picture, I've turned both the focusing ring and the aperture ring as far as they would go (in opposite directions).

 

That's why I was wondering about the DOF indicator itself.

 

Oh, one other data point: when the lens is on the camera, the index mark on the lens is NOT at 12 o'clock. Rather it seems like it's turned about 15 degrees clockwise (when looking from the back of the camera).

 

Thanks for the suggestions, though. When I get home tonight, I'll double-check that it's not focusing past infinity.

As long as the lens doesn't focus past infinity it should work fine. The Mamiya 500 DTL was (and still is) a fine entry into the M42 lens world. If you can't get the scale to line up it's not expensive to find another lens.

As long as the lens doesn't focus past infinity it should work fine. The Mamiya 500 DTL was (and still is) a fine entry into the M42 lens world. If you can't get the scale to line up it's not expensive to find another lens.

 

Thanks, Mike.