Care to be a bit more explicit? The word "crop" does not appear in his
article so I don't know what you're referring to. When working with a
"cropped" sensor I just apply the "crop factor" (2 for four thirds) as a
divisor to the CoC that I would normally use for full frame. The CoC
gets smaller since the final image is going to be magnified more.
Chuck Norcutt
Ken Norton wrote:
>> Normally said as "all wet" rather than "completely wet". At least I
>> think that's what he meant. See definition #2 here:
>> <http://en.wiktionary.org/wiki/all_wet>
>>
>
>
> I think his conclusion is correct, but the path to get there is wrong. The
> math does not match his assumptions--especially in the discussion about
> cropped image vs longer focal-length. This is when his theories break down
> because as Chuck has clearly stated, in order to calculate DoF you must work
> from a known output size (magnification). Ctein is using "non-test tests to
> figure this out and is being fooled by how different optical designs can
> alter other imaging characteristics which can be misinterpreted as an
> increase/decrease in DoF.
>
> AG
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