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06-03-2013, 10:45 AM   #1
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Modification of a K24/2,8 to "A"

Hello

During the last day I modified a manual K24 to Auto-Mode



Using a K7 it can be adjusted fom 2,8 to 22 (as it should) and exposure is OK at 2,8 and needs to be adjusted by minus 0,5 step for each step the aperture is closed (means F8 --> - 1,5). Without this correction it causes over-exposures the more you close the aperture. It is caused by a lack of linearity in these old lenses but I think that is something I can use.

BUT- The results on my K01 are surprisingly inconsistant..........

More Details at http://klaus-takes-pictures.blogspot.de/

06-03-2013, 10:59 AM   #2
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Interesting, but in terms of lost resale value on the K24,
the cost of your time working on it,
and the non-linearity you mention,
wouldn't it have been better just to buy an A24?
06-03-2013, 11:03 AM   #3
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I wish some Chinese manufacturer comes up with readymade mounts, would be a lot easier. Thanks for sharing
06-03-2013, 01:37 PM   #4
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QuoteOriginally posted by klaus123 Quote
Hello

During the last day I modified a manual K24 to Auto-Mode



Using a K7 it can be adjusted fom 2,8 to 22 (as it should) and exposure is OK at 2,8 and needs to be adjusted by minus 0,5 step for each step the aperture is closed (means F8 --> - 1,5). Without this correction it causes over-exposures the more you close the aperture. It is caused by a lack of linearity in these old lenses but I think that is something I can use.

BUT- The results on my K01 are surprisingly inconsistant..........

More Details at http://klaus-takes-pictures.blogspot.de/
Right, the levers on K lenses are linear while those on A lenses are logarithmic (or vice-versa), so the conversion isn't quite that trivial, unfortunately.


Adam
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06-03-2013, 01:58 PM   #5
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Just to fix a baseline,
was the K24 exposing properly before the conversion?

These old lenses often have sticky blades.
06-03-2013, 02:38 PM   #6
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Sorry to say, but this modification is a crime, particularly considering the amount of information on this site and many other places on the Web counseling that it will not work.


Steve
06-03-2013, 02:58 PM   #7
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QuoteOriginally posted by klaus123 Quote
Hello

During the last day I modified a manual K24 to Auto-Mode



Using a K7 it can be adjusted fom 2,8 to 22 (as it should) and exposure is OK at 2,8 and needs to be adjusted by minus 0,5 step for each step the aperture is closed (means F8 --> - 1,5). Without this correction it causes over-exposures the more you close the aperture. It is caused by a lack of linearity in these old lenses but I think that is something I can use.

BUT- The results on my K01 are surprisingly inconsistant..........

More Details at http://klaus-takes-pictures.blogspot.de/
You are such a barbarian to have mutilated such a nice lens....
06-03-2013, 04:10 PM   #8
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QuoteOriginally posted by stevebrot Quote
Sorry to say, but this modification is a crime
Which I committed on a much cheaper Five Star 28mm acquired on Ebay It works decently enough on my K-01, but under some lighting condition the camera goes nuts with its non-stop stop down/open up squinting act.

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