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11-26-2010, 03:14 AM - 1 Like   #1
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Trap focus using non-central AF points

Hello all I have just joined this forum and this is my fist message!
Reading previous threads it appears that with a K20D and using a DA* lens such as the DA*60-250 or DA*50-135 it is possible to use trap focus (also known as snap focus or catch focus) without being limited to use the central focus point. In other words by setting these lenses to MF (using the button on the lens) it should be possible to SELECT the AF point (one of the 11), or else use AUTO and let the camera choose the AF point to trap focus with. Has anyone had experience with this method, does it definitely work? Important for me as I am contemplating buying a DA*60-250mm lens for this reason. I am a nature photographer. Thanks!

11-26-2010, 04:52 PM   #2
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As far as I know it's limited to center focus only. I've used it on manual and AF lenses. Including the 50-135 and 16-50.

11-26-2010, 11:04 PM   #3
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Hi Dipper,

You are correct in your assumption that it works with all 11 focus points -- I just tried it with my K-7 and DA* 50-135. I already had it set to "Catch-in Focus" "on", set the AF to AF-S, and switched the DA*50-135 to "MF". Using SEL mode, I set the focus point to the farthest to the right, held a subject at that point, then rotated the focus ring while holding the shutter full down. When the subject came into focus, it fired, indicating the full right line sensor location.

Nice thinking!

11-30-2010, 03:56 AM   #4
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Original Poster
Thanks a lot Scott for verifying that this actually works! I will go ahead now with my purchase, I'm assuming that if it works with the K-7 it will also work on the K20D, (I know it will NOT work using the K10D). Also you tested using the DA* 50-135 lens while I am interested in the DA*60-250mm lens, but I'm sure this won't be a problem as they are both in the same "family" of lens. Thanks again! Paul


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