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09-16-2011, 05:18 PM   #1
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K200 wont auto focus??

I have been slack, and not used my camera for over 1 yr

I pulled it out to start using it again, and all was fine for that day

I have 2 lenses - one is the sigma 18-50mm 1:3.5-5.6 that can with it, and one is a SMC Pentax-FA 1:4.5-5.6 80-320mm zoom from my old pentax 35mm

Next time I used it, the small lense would auto focus, but the zoom wont

If I put the small lense on, the display says auto focus - put zoom on and it says manual focus no matter what setting I have it on - any ideas??

Could it be a setting or is my zoom lense broken?

09-16-2011, 06:03 PM   #2
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I trust that you have verified that the big zoom is mounted correctly - turned all the way into the bayonet and that the lens contacts are clean and that you have tried to flip the AF/MF switch back and forth a couple of times. If so it would appear that there is something wrong with the lens since your small lens does autofocus correctly.
09-16-2011, 06:17 PM   #3
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Hello heavyduty, and welcome to the forums.

If you can use AF with the Sigma and not the Pentax, it's likely an issue with the Pentax lens.

Can you change the aperture value for the zoom lens successfully (in camera)? If not, the contact furthest from the red alignment mark may have some dirt or oxidation on it.
09-16-2011, 06:40 PM   #4
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In the past it has worked faultlessly - Im hoping it isnt broken

I have tried lightly cleaning connections - all looks good there. It seems like it isnt telling the camera to use auto focus

Might have to get someone to look at it for me

Another thing I noticed is that when I put the zoom on and turn the camera on it asks me to input the focal lenght - it never used to do that!

09-16-2011, 06:47 PM   #5
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The pin I mentioned above is the one that communicates with the camera about AF and a host of other information. Among those things also communicated is the aperture setting (for lenses with on lens aperture dials set to "A"). If it consistently reports as MF and you cannot change the aperture, and the contacts on both sides are clean, the chip in your lens may have kicked the bucket.

If you can change the aperture but still cant focus, I have no idea!
09-17-2011, 05:57 PM   #6
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Thank you for the help feilb - I have tried to cleanall contacts, so the next thing is to get someone to check the lens on another camera for me

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