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10-07-2009, 07:47 PM   #1
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K10D auto focus problem

I have had this camera since early '2007. I have experienced intermittent problems w/the auto focus. At times, I have to switch to manual focus as the camera will not function in auto focus mode. It makes no difference what lens I am using. I have the Pentax 55-300mm, the Pentax 18-55mm, the Pentax FA 50mm and the Sigma 10-20mm lens. The problem created by this is that at times when in manual mode inadvertently the focus ring moves slightly when doing quick photo captures thus creating a blurry photo. I am sure this has been addressed before (could find nothing in search) but am wondering if there is any fix for this. TIA for your help.

10-07-2009, 08:23 PM   #2
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G'day Dales.
I'm not sure I'm going to be helpful with this, but do let me know if I'm on the wight track...
You're saying that AF intermittently doesn't work - at those times does it engage at all, or there's just no movement in the focus ring? Does this happen over a period of time, or just with one half-press of the shutter button?

You also said that the focus ring moves in manual mode - is that the camera's manual exposure mode, or manual focus mode? MF should mean all autofocus functions are overridden and you should have total control of the focus ring. Is this not so? Manual exposure mode has no bearing on focusing.

Be weary also that only your 18-55 and 55-300 lenses have the quick-shift function, which allows you to manually focus the lens in autofocus mode after the camera has locked focus itself.
10-07-2009, 08:43 PM   #3
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It's normal that the camwera might have trouble ac hieving focus lock in certain situations - lw light, low contrast subject (plain white wall, for instance), closer than minimum focus distance, etc. So if the failure to focus is in these types of conditions, that's normal for any camera. As for the focus ring moving while in MF mode, it shouldn't do that of it's own according - or do you maybe mean you are accidentally brushing it with your finger or something like that?
10-07-2009, 09:09 PM   #4
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Thanks so much for the quick replies. When this non-AF happens the conditions (lighting, etc) have not changed from when the AF was working. I will be shooting a subject in AF than for some reason the AF function stops and I than have to switch the camera to MF. Yes, the out of focus is probably caused by my finger brushing the focus ring thus throwing it out of focus. I shoot a good deal of high school sports and need to make some quick movements thus not to careful at times in possibly moving the focusing ring while it is in manual focus. By far my preference would be to leave it in AF. Hope this clarifies some of the unanswered questions I left open w/the 1st thread. Thanks again for your help.


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