[Leica] Fungus now filters

[dorysrus at mindspring.com (Don Dory)]

All,
The Kodak Pro14 or whatever their full frame 14MP camera is rumored to
not use an anti-aliasing filter.  Likewise the internet rumor is that
the D70 does not use one.

At least with the D70 I believe software is used to take the artifacts
away as my friends give really mixed reviews to the output of this
camera.  Like all software, it does what it was written for so if the
subject matter looks like moir? then it will be removed.

My own tests with the D70 would seem to confirm this theory.  Shots of
static objects with edges look really good.  Shots of complicated
leaves, petals, and other really fine detail look like Summar images
wide open(exaggerating here to keep some Leica content).

I wish Austin was still on the list as I believe that some chip design
of some large number of pixels at some pixel pitch could show few
artifacts of detail that the human eye could see.  Really, an
engineering problem using acuity tests for the human eye and physics to
design a sensor that minimizes artifacts in that frequency range.

Don
dorysrus@mindspring.com

-----Original Message-----
From: lug-bounces+dorysrus=mindspring.com@leica-users.org
[mailto:lug-bounces+dorysrus=mindspring.com@leica-users.org] On Behalf
Of Adam Bridge
Sent: Friday, July 02, 2004 1:37 AM
To: Leica Users Group
Subject: Re: [Leica] Fungus in camera

It seems very odd to me that Leica is trying to eliminate the
anit-aliasing filter. I distinctly remember my digital signal
processing courses that state that before you sample an analog signal
you have to limit the bandwidth with a filter to at least half the
sampling frequence (and that would be if you had a perfect low-pass
filter, you have to go lower for real-world filters.) Moire patterns
would be the result because artifacts would be generated by digital
sampling. I had a real-world example of this where we were measuring
ion-acoustic waves in very low-density argon plasmas and got results
that were really exciting - until the experimentalist realized he
hadn't built-in the low-pass filter. When the filter was installed the
"exciting" results vanished and things approached theory. Oh darn. But
that wasn't with optical systems and maybe someone who's won the
galactic institude prize for extreme cleverness has figured out how to
avoid the artifacts.

I sorta hope so....but I'm wary of free lunches.

Adam

On Thu, 01 Jul 2004 08:49:02 -0400, Dan C <bladman99@yahoo.ca> wrote:
> The other article concerns the digital back for the R8/R9.  They are
aiming
> for a December launch, but they seem to be having problems getting the
> internal image processing software ready.  Leica isn't happy with it.
An
> "anti-aliasing" filter isn't be used, and they appear to be having
problems
> solving the resultand moir? patterns visible is some images.   But
they are
> also confident these problems will be solved.   No sample images yet.
> 
> -dan c.

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