Archived posting to the Leica Users Group, 2003/03/18

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Subject: [Leica] Re: Leica DSLR
From: Jim Brick <jim@brick.org>
Date: Tue, 18 Mar 2003 07:27:53 -0800
References: <NABBLIJOIFAICKBIEPJJEELAEOAB.darkroom@ix.netcom.com> <5.2.0.9.0.20030317171347.02923e48@192.168.100.11> <5.2.0.9.0.20030317184136.02919258@192.168.100.11>

At 09:36 PM 3/17/2003 -0800, Mark Rabiner wrote:

>When i finally get a digital camera or
>back I'll enjoy not one piece of dust.

One of the biggest problems with digital cameras with removable 
(interchangeable) lenses is dust. The sensor (CCD or CMOS) after having all 
of those electrons running through it to capture an image, builds up a huge 
amount of static electricity. Take the lens off and it's like a giant dust 
vacuum cleaner magnet. Ask any pro digital shooter or pro digital rental 
department. Same goes with a digital back. Keeping the sensor dust free is 
a G=I=A=N=T JOB. This is one reason that consumer digital cameras aren't 
offered with removable lenses.

>But also the ultra high specs of Leica lenses are wasted on aiming it's
>light on a digital sensor grid (I forgot what these commonly known
>things are called).


It's called the Nyquist limit. The MTF frequency of a lens should be around 
four times less than the frequency of the sensor. All sensors used in pro 
cameras have a low pass filter over the sensor to dumb down the lens. 
Digital is the great lens equalizer. It matters little whether you use 
Canon, Nikon, Oly, Leica, or whatever lenses. They're all dumbed down to 
the same MTF frequency.

Jim

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In reply to: Message from "Austin Franklin" <darkroom@ix.netcom.com> (RE: [Leica] Leica DSLR)
Message from "Richard F. Man" <richard@imagecraft.com> ([Leica] Leica DSLR)
Message from "Richard F. Man" <richard@imagecraft.com> (RE: [Leica] Leica DSLR)