Retrofocus and DOF

[P3D John Bercovitz <bercov@xxxxxxxxxxx>]

BobH writes:

> To make it stickier all 50mm SLR lenses are "retrofocus" type to  
> clear the mirror which can alter depth of field formulae also.

I hadn't thought about that.  Can you give me some pointers?  I have 
thought about the position of the entrance pupil and its effect upon 
on-film deviation.  Sounds like we have another complicating factor
from retrofocus lenses here.

Thanks,
John B

PS: Sorry about all the confusion due to my posts on format.  I see
two problems: 1) I didn't recall the lens spacing problem early
enough.  2) I'm violating the law of requisite complexity by making
my posts shorter than the minimum required to explain the subject.


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