Re: Viewing angle

[T3D john bercovitz <bercov@xxxxxxxxxxx>]

BobH writes:

> Canon has stated in their "Lens Book" that 100mm is the lens that
> equals human vision....

How do you view statements like that, Bob?  Seems mushy to me.  Maybe 
Jim Crowell can comment.  Seems to me that one has a central area of 
sharp vision and that if falls off from there pretty steadily out to 
90 degrees off axis.

I look at it as a problem in perspective, a problem in what distance 
people typically view photos from.  I think people view 4x5 and 4x6 
prints from about 16" and 8x10s from about 24" when they're holding 
the print.  So in the 4x5 format you would use a 16" lens for contact 
prints and a 12" lens for 2X enlargements.  Similarly in 35 mm format, 
you would use 100 mm for a 4x6 print and 70 or so for 8x10s.

John B


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