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07-14-2013, 06:10 AM   #1
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No focus lock

I have a new K-30, and I bought a used 18-135 from KEH that looks to be in like-new condition. The problem is it won't lock focus on distant objects between 18 and 70mm. At 18 and beyond 70 everything's fine, but between those focal lengths I can only focus on near objects. This doesn't happen with other lenses I've tried.

Any quick adjustments I can try before I send it back?

07-14-2013, 09:40 AM   #2
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If you can achieve proper focus by focusing manually, try applying a positive AF correction value (i.e. +5). If that still doesn't help, I'd just return the lens or get a new one.

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07-14-2013, 06:00 PM   #3
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You're not alone: Pentax 18-135mm does not focus to infinity below 33mm

Apparently, the lens can't focus to infinity at the focal lengths you specified. If you go into Live View and try manually focusing at a distant object, and there is no point in the focusing range where the subject is clearly in focus (you hit the infinity stop on the focusing ring and the subject is still soft), the lens requires repair. You should exchange the lens; a technician would have to adjust the focusing helicoids inside the lens to correct this defect.

07-14-2013, 07:14 PM   #4
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Thanks. Back it goes.


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