MZ6 only meters at min aperture in M mode
Posted 12/05/2016 - 20:40
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An M lens set wider than f22, say f8, can only stop down to what it is set to, in that case f8. M lenses do not have electrical contacts so cleaning the mount contacts on the body will make no difference, just set the aperture and the camera will work out the shutter speed (and should show you the shutter speed in the viewfinder, just like using the lenses on an M series camera.) With the DSLRs now you have to press the green button to take a reading, but not so with that.
With the A lens, you can either set the aperture on the lens and it will work like your M lens, or put it on the A setting (just beyond f22) and you can set the aperture from the camera body as you would with a current DSLR (it'll use those contacts to communicate.)
With the A lens, you can either set the aperture on the lens and it will work like your M lens, or put it on the A setting (just beyond f22) and you can set the aperture from the camera body as you would with a current DSLR (it'll use those contacts to communicate.)
John K
Posted 12/05/2016 - 21:28
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Thanks, John. The problem is slightly different though. If I set the aperture ring on my M lens to, say, 2.8, the camera will indicate a shutter speed for correct exposure of 1/4 sec rather than 1/20 and will meter for this regardless of what I set the aperture to. Does that make sense?
On my 50mm 1.7, the indicated aperture is f32 if I take it off A. On my Sigma 24mm it shows as f64! And meters accordingly. Weird.
On my 50mm 1.7, the indicated aperture is f32 if I take it off A. On my Sigma 24mm it shows as f64! And meters accordingly. Weird.
Posted 12/05/2016 - 21:55 - Helpful Comment
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I see. I described what should happen, if it isn't then it sounds like there maybe an issue with the camera body. Has this issue just happened or is it a new to you camera?
What I suspect is wrong is the linkage known as the aperture simulator on the right hand side of the mount (as you're looking into it.) This is the linkage that was removed in later Pentax's, hence the term crippled mount. I wonder if that linkage lever has been removed or simply got bent out of position so the camera isn't able to read the aperture setting on the lens. If you have another Pentax film body perhaps compare those coupling levers. It might even be that the lever is working fine but something is broken where that data gets transferred to the electronics, possibly a dirty potentiometer.
If its a recent purchase consider returning it though you say the electronic metering is OK so you'll just be restricted to using that. I doubt it would be economic to get it repaired.
What I suspect is wrong is the linkage known as the aperture simulator on the right hand side of the mount (as you're looking into it.) This is the linkage that was removed in later Pentax's, hence the term crippled mount. I wonder if that linkage lever has been removed or simply got bent out of position so the camera isn't able to read the aperture setting on the lens. If you have another Pentax film body perhaps compare those coupling levers. It might even be that the lever is working fine but something is broken where that data gets transferred to the electronics, possibly a dirty potentiometer.
If its a recent purchase consider returning it though you say the electronic metering is OK so you'll just be restricted to using that. I doubt it would be economic to get it repaired.
John K
Posted 12/05/2016 - 23:07
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Sounds about right. Doesn't appear anything visually amiss so may well be down to some electronic jiggery pokery as you suggest. Got for much cheapness so definitely not worth the repair. Oh well....
Posted 12/05/2016 - 23:21
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Sounds as if its OK with anything other than purely manual lenses, so at least it's still usable.
John K
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53 posts
15 years
Edinburgh
The camera works fine in auto, AV mode etc but in manual mode it will only meter at the minimum aperture (e.g. F22) regardless of the position of the aperture ring. I've tried this with three different lenses (2 A and one M lens) but run into the same problem. I've tried cleaning the mount contacts.
Am I missing something?
Cheers.