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m42 lenses

redbusa99
Posted 15/08/2010 - 09:21 Link
i see a lot of people use m42. how do you adapt so the apeture ring can be used? i tried one but the pin is on the base of the thread and there is nothing for it to come into contact with on the adapter. k7 camera. any help much appreciated as reading through forums some of these are very good lenses at a reasonable price.
odd lens or 2

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hefty1
Posted 15/08/2010 - 11:31 Link
M42 lenses come in three basic flavours:

1) Manual only (usually a pre-set aperture like the Jupiter-9 etc)

2) Manual and Auto (set by a switch on the lens barrel)

3) Auto only (actually quite rare but applies to later versions of the Helios-44)

If you have a lens that falls into (1) or (2) then it's quite simple to set the aperture, I'd say 90%+ of all M42 lenses fall in these groups.

If you have a lens that falls into (3) then you need to find a way of keeping the pin permenantly depressed - some use glue (which then permanently alters the lens) others may take the back off and use a spacer (reversible if the need ever arises).
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redbusa99
Posted 16/08/2010 - 01:03 Link
thanks hefty1 only have a tokina rms 100-300 at the moment and that falls in group3. so out with the araldite.
odd lens or 2

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