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10-06-2011, 09:19 PM   #1
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M 50 1.7mm

I've been using this on my kx and my question is... It doesn't seem to make a difference whether i shoot with it wide open or any other aperture setting. A limitation of it being manual? The dslr can't "read" what aperture setting it is on? If so...what to do about it?

10-06-2011, 09:21 PM   #2
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Hmm...redundant post? I just saw the sticky, up top...
10-07-2011, 04:48 AM - 1 Like   #3
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depend if you shoot on Av or M, in Av mode it will always shoot wide open, in M mode, pressing the +/- EV gives youthe best speed for the aperture set.
10-07-2011, 05:59 AM   #4
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That is indeed the correct and short answer. A longer explanation would be that by the time the M lenses were in production, the M-series bodies had an additional lever that could detect what aperture the lens was set at. With the introduction of electrical contacts, that lever became redundant, and at one point has been completely removed from the bodies (don't ask me why), rendering the old M lenses unusable in Av mode, just in M (stop-down metering) mode - it's called crippled mount.

10-07-2011, 06:58 AM   #5
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Although my MZ-5N and MZ-6 have non-crippled mounts, when I use M lenses, they still display F--.
10-07-2011, 11:54 AM   #6
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QuoteOriginally posted by kcobain1992 Quote
That is indeed the correct and short answer. A longer explanation would be that by the time the M lenses were in production, the M-series bodies had an additional lever that could detect what aperture the lens was set at. With the introduction of electrical contacts, that lever became redundant, and at one point has been completely removed from the bodies (don't ask me why), rendering the old M lenses unusable in Av mode, just in M (stop-down metering) mode - it's called crippled mount.
actually the lever was introduced in the spotmatic F and ES II bodies, and on the SMC takumar lenses , where they developed open aperture metering. In K mount bodies, the cameras ALWAYS knew how many stops down from maximum aperture

QuoteOriginally posted by violini Quote
Although my MZ-5N and MZ-6 have non-crippled mounts, when I use M lenses, they still display F--.
that is because the camera does not know aperture, only how many stops down from maximum the lens is set to.

The K mount definition is based upon the relitive change in aperture setting between open and where the ring is set.

KA bodies, when in A mode, know the maximum aperture from the lens coding, and the body determines through the movement of the aperture control lever, how far down the lens will close when the shutter is tripped, as a result a KA lens will show true shooting apetrure but K or M lenses show F---
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