Camera and lens disconnect.

[xkaes]

I once had a Vivitar 283 flash that would not work on one particular Minolta SRT camera -- but it worked fine on all my other SRT cameras. But that SRT camera worked fine with several other Vivitar 283 flashes – but not that one flash. I’ve never figured that one out.

Today I have a similar problem. I use Minolta Maxxum and Sony a-mount, full-frame cameras, and lots of a-mount lenses. They all work fine, but I have one lens and one camera that don’t like each other.

It’s an a850 that works fine with all my lenses except one – a Sigma 60-200mm – but the Sigma works fine on all my other cameras – including two other a850 cameras.

The a-mount cameras have a lever in the lens mount that keeps the aperture open all the way until the moment of the exposure – when it moves to stop down the lens. After the exposure, it moves back up the top -- and opens up the lens again.

The corresponding lever on the lens stays DOWN when the lens is not on the camera, but when it is attached to the camera, the lever in the camera keeps the lever in the lens in the OPEN position – until the exposure. After the exposure, the lever in the camera moves and opens up the lens.

When this Sigma lens meets this Sony a850 they work fine for the first exposure. But after the lens stops down for the exposure, the lens does not open back up. When I remove the lens, the aperture closes back down, as it should, but the lever in the camera does not return to the top, as it should.

You might assume that the fault is with the camera, but it does not do this with any other lens. The camera opens up every other lens that I ha correctly. Ad this lens only has this problem with this lens -- it works fine with all my other cameras.

The lens attaches correctly to the camera – not tight or loose -- so I don't see how there is a physical connection problem.

I can solve this problem by not using this lens on this camera, but that's not ideal.

Anyone ever have a similar problem.

 

[F4U]

It just the way it is. I've got a 35mm Nikkor that will not index on my F motor drive body but work on ever other body. Don't think too much of it.

 

[Paul Howell]

I once had a Vivitar 283 flash that would not work on one particular Minolta SRT camera -- but it worked fine on all my other SRT cameras. But that SRT camera worked fine with several other Vivitar 283 flashes – but not that one flash. I’ve never figured that one out.

Today I have a similar problem. I use Minolta Maxxum and Sony a-mount, full-frame cameras, and lots of a-mount lenses. They all work fine, but I have one lens and one camera that don’t like each other.

It’s an a850 that works fine with all my lenses except one – a Sigma 60-200mm – but the Sigma works fine on all my other cameras – including two other a850 cameras.

The a-mount cameras have a lever in the lens mount that keeps the aperture open all the way until the moment of the exposure – when it moves to stop down the lens. After the exposure, it moves back up the top -- and opens up the lens again.

The corresponding lever on the lens stays DOWN when the lens is not on the camera, but when it is attached to the camera, the lever in the camera keeps the lever in the lens in the OPEN position – until the exposure. After the exposure, the lever in the camera moves and opens up the lens.

When this Sigma lens meets this Sony a850 they work fine for the first exposure. But after the lens stops down for the exposure, the lens does not open back up. When I remove the lens, the aperture closes back down, as it should, but the lever in the camera does not return to the top, as it should.

You might assume that the fault is with the camera, but it does not do this with any other lens. The camera opens up every other lens that I ha correctly. Ad this lens only has this problem with this lens -- it works fine with all my other cameras.

The lens attaches correctly to the camera – not tight or loose -- so I don't see how there is a physical connection problem.

I can solve this problem by not using this lens on this camera, but that's not ideal.

Anyone ever have a similar problem.

I don't have as many A mount Sony bodies, but other than an early Sigma 400 5.6 that will only AF on a A9000 or 7000 film body all my Sigma and Tamron lens work on my A700, 900, and A77II without issues. Very odd.

 

[xkaes]

I'm aware of some a-mount lenses not totally working on some a-mount cameras, but the problem is usually dead auto-focusing, or not setting the aperture on certain camera models. This lens doesn't have those problems. Plus, it works fine on two of three a850 cameras, but not a third. The only glitch is that it doesn't reset to full aperture after the exposure.

 

[Paul Howell]

No idea, your question is spot on, why only 850 body, and all other lens work on that body.

 

[MattKing]

In some cases, you might be running into apparently minor differences relating to where/when each camera body and lens fits into the production timeline for the product.

 

[Rockaway Studios]

Gerfunkulator cam misaligned with the borkferdining pin, sounds like. Same thing happened to the fuel injection nozzles on my 1987 Volvo after a car wash in Cedar Rapids. Did you take either the lens or body through any car washes?

seriously, though, Matt King might sort of have it…the phenomenon of “stacking tolerances”. Both pieces may be manufactured to the outer edge of one of the tolerances for the mount.. You other stuff is all closer to the target dimension. When those two particular pieces come together, the combined (“stacked”” tolerances are too great somewhere in the mount, out of the spec, and therefore cannot work together. With any other combination, the tolerance stack is still in spec.

 

[loccdor]

In the realm of junky Soviet Union equipment, I've come across lenses/cameras/teleconverters that had varying lengths in the aperture pin mechanisms from model to model. Some combinations could operate the auto-aperture correctly, other combinations could not. I would expect the dimensions of your equipment to be up to a higher standard, but maybe not quite enough in this case?

 

[xkaes]

If had never run across a similar, inexplicable hardware incompatibility before, I would probably try to figure out the problem -- even if it could not be solved. But I have bigger fish to fry. I will somehow try to remember not to use that particular lens with that particular camera.