T3D Re: DOF equal and ?

[john bercovitz <bercov@xxxxxxxxxxx>]

> you maybe are not paying attention to how severe EQUAL IMAGE 
> size is

I think I am.  Kingslake says if they are blown up to the same
size and viewed from the same center of perspective, they will 
have the same DOF provided the same linear aperture was used.  
I doubt I can think of any more ways to say it and I doubt you 
can think of many more ways to say what you're saying.  That's 
why I recommend your reading Kingslake's book and telling me if 
what you're saying agrees or disagrees with what he is saying.  
Alternatively, maybe you could cite a reference that supports 
your point of view and I can look in it and see if I think it 
agrees with Kingslake.  Even simpler might be for you to pull 
down Kingslake's DOF analysis from one of the web sites and let 
me know if you agree with it.  If you do, we don't have a 
difference of opinion, only a different way of saying it.  

In order to view from the same center of perspective when the 
images from the two formats are the same size, the lens focal 
lengths have to be proportional to format size.  Not sure if 
you are including this change in focal length in your proposition.  
If the lens focal lengths aren't proportional to format size, 
coverage is not equal.  Here I'm applying Kingslake's analysis to
stereo.

John B


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