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09-20-2017, 05:39 PM   #1
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Are metal K lensmounts aluminum or Stainless steel?

Are metal K mount lensmounts on lenses and bodies aluminum or Stainless steel?


Why I want to know is I was testing my new 3rd party KAF lens, and found out catch in focus isnít possible without a workaround.

People use aluminum foil, to short the pin, but I thought thatís a bit rinky dink, and prone to shredding, so I tested out feeler gauges and a 0.04mm one works well.

The thing is aluminum is soft, so if the lens mount is made of it I don't want to erode it using a brass feeler gauge.


09-20-2017, 08:15 PM   #2
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QuoteOriginally posted by pentax360 Quote
Why I want to know is I was testing my new 3rd party KAF lens, and found out catch in focus isn’t possible without a workaround.
CIF does not work with AF lenses except for those that have in-lens focus motors and an on-lens on/off switch. With that switch in the "off" position and the switch on the body in the AF position, CIF may work. Again, CIF generally does not work with AF lenses.


Last edited by stevebrot; 09-20-2017 at 09:10 PM.
09-20-2017, 10:53 PM   #3

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QuoteOriginally posted by dcshooter Quote
Neither. They are chromed brass.
Not all, it depends.
10-01-2017, 12:17 AM   #4
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Thanks, just what I needed to know.

10-01-2017, 12:29 AM   #5
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QuoteOriginally posted by dcshooter Quote
I should clarify. All Pentax-made K mount lenses and bodies have chromed brass mounts.

Third party lenses with black mounts typically use anodized aluminum. Anything silver on a third party lens is nearly always going to be chromed brass as well. Stainless steel is not used as it is harder to machine, more expensive, and causes undue wear to the camera side bayonet. I've seen a couple of lenses with silver toned anodized aluminum bayonets, but that's literally one or two out of thousands.
Yeah, but what would you know?

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