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05-27-2011, 09:17 AM   #1
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Pentax-A lens Problem with K-x

I bought a pentax-a 50mm f/2.0 a while ago for my K-x.

As my research goes, pentax-a lens can work just like DA lens except no AF.
But when I use the lens I am not able to use the aperture control on the camera.

When I switch to Av mode, exposure level works fine but stuck with f2.0 wide open; turn the aperture ring on the lens to F4, F8, etc, and still nothing change.
When I switch to M mode, aperture ring works fine just like any other M series lens.

So what is the problem here? Is it my K-x not able to use A lens or is there some hidden option I need to change?


05-27-2011, 09:28 AM   #2
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Is the aperture ring on the lens set to the "A" position?
05-27-2011, 09:29 AM   #3
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When using 'A' lens on my K-X I leave in auto pic mode and sitch to manual focus,works fine.There may be a setting wrong in your menu to keep it from working.
05-27-2011, 09:35 AM   #4
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Original Poster
I never notice the "a" on the very end of the ring.
Now everything's working perfect thanks!

05-27-2011, 09:36 AM   #5
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Custom Settings "Using Aperture Ring" should = Permitted. This will allow you to use the lens' aperture ring to set aperture. If you do not do this the system will meter wide open regardless of your ring setting. If you want the body to control the aperture settings you need to make sure the lens aperture ring is in the "A" position as deadwolfbones pointed out.
05-27-2011, 09:39 AM   #6
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When you use the A lenses, you are supposed to leave the lens on the A setting and the camera will automatically adjust the f-stop when you shoot (setting the aperture in Av and M modes). This is a very nice convenience and except for auto focus and auto recognition of the focal length, the lenses work just like the newer auto focus lenses.

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