Re: Effects of lens length

[P3D Dr. George A. Themelis <DrT-3d@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

>> question -
>> if you crop an image taken with a 50 mm lens to the same part as
>> an image taken with a 80 mm lens, and make them the same size - would
>> you have the same thing as two pictures both taken with 80 mm lenses?
>> 
>No. The length of a lens impacts the relationship of foreground and 
>background objects.

Sorry Marvin, but I think the answer is "yes".  The FL will only affect
the magnification. If you are standing at the same spot then you can
magnify or reduce pictures taken with different FLs for perfect match.
BUT, if you move to match the field of view of the two lenses, then
you have altered the perspective or, as you say, the relationship of
foreground and background objects.

It's a simple concept and yet not many people get it right.

George Themelis


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