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12-24-2009, 06:23 AM   #1
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Location: NSW
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What focal length input

Hi and "Season's Greetings" to you all.

I hope someone can help me with this. I recently got my first DSLR (Pentax K20D) and I still have some prime senses from my film days. When I use these (in manual mode) on my K20 it asks me to put-in the focal length. This will sound stupid, but do I put in the FL (say 50mm as on the lens, or do put in the multiplied (1.5x =75mm) as the sensor will see it?

The manual doesn't explain.

Thanks and cheers for now.

12-24-2009, 06:28 AM   #2
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Join Date: Aug 2009
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Enter the focal length listed on the lens.

BTW, this focal length never changes - the field of view (FOV) may change based on sensor/film size, but the focal length never changes.
12-24-2009, 06:46 AM   #3
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Thanks heaps for that, singlespeed!

Question answered
12-24-2009, 09:15 AM   #4
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In addition to what singlespeed said; if you can't enter the exact focal length, i.e. there is no menu option for your particular lens, enter the closest FL that is less than the actual focal length. I tested this quite a bit, and under compensation of SR seems to give better results than over compensation.


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