[Leica] Re: optics for digital

[Jim Brick <jim@brick.org>]

At 02:51 PM 5/7/2003 -0500, George Lottermoser wrote:

>For all techies who have found interest in the optical requirements of 
>digital - Schneider has a white paper on their thoughts:
>
><http://www.schneideroptics.com/info/white_papers/optics_for_digital_photography.pdf>
>
>Fond regards,
>
>G e o r g e   L o t t e r m o s e r,    imagist


I've been pointing folks to that white paper for a couple of years now. And 
I still get poo poo'ed. And I also said that this is why Schneider (and 
others) make a complete set of LF lenses for digital. They are computed to 
produce a lower MTF frequency than film lenses. This way a low pass cut-off 
filter is not needed over the digital sensor. This increases sharpness in 
many ways.

All high-end digital SLR's that use film camera lenses have a low pass 
cut-off filter over the sensor to dumb down the lens to match the sensor 
pixel frequency. This is unnecessary with film because the grain structure 
of film is random and much much tighter than current pixel spacing.

For Kodak digital backs, you can buy this cut-off filter as an accessory, 
specifically to quell aliasing.

Jim

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