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10-16-2013, 02:41 PM   #1
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Pentax 645 lens on apsc format

HI PENTAXIAN,

Just wondering if you all can help me to get more clear understanding about this.

if i put 645 lens let say 120mm f4 macro to my k10D, do i get about 120mm x 1.7 (full frame crop factor) x 1.5 (full frame to crop sensor ) = 306mm focal length equivalent?

how about the f stop, close focus range and magnification, do they also multiply by 2.55?

thanks for all your help.

10-16-2013, 02:52 PM   #2
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QuoteOriginally posted by wmf2012 Quote
HI PENTAXIAN,

Just wondering if you all can help me to get more clear understanding about this.

if i put 645 lens let say 120mm f4 macro to my k10D, do i get about 120mm x 1.7 (full frame crop factor) x 1.5 (full frame to crop sensor ) = 306mm focal length equivalent?

how about the f stop, close focus range and magnification, do they also multiply by 2.55?

thanks for all your help.
Forget crop factor. A 120mm 645 lens on your K10D will offer the same field of view and aperture as a 120mm k-mount lens.

It would be equivalent in terms of field of view to a 300mm lens on the 645.

Adam
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