Archived posting to the Leica Users Group, 2009/07/22

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Subject: [Leica] Software lens correction
From: hopsternew at gmail.com (Geoff Hopkinson)
Date: Thu, 23 Jul 2009 09:13:34 +1000
References: <cda.4d0dee69.3798edab@aol.com>

Larry, Geoff did not write the quoted part ;-) Actually I was linking to the
new DNG standard which has implications for lens and camera designs (for
cameras using DNG). What stands out for me about that is it may become
possible to adjust the corrections now made in firmware (for vignetting for
example) in your converter. At least Adobe's converters.
I wasn't making a case for or against software correction of optical
deficiencies though. I just commented that Leica's approach is to make the
optics as good as possible since that is their strength. That costs a lot of
money as we all know. Lots of folks think it is worth it, of course. If you
start with the best possible optical information then it gives more
possibilities for later adjustment, not less. The penalty of course is in
the design and costs of those lenses, which is why the industry giants in
Japan elect to not use that approach. Clearly a valid choice for them.

Interesting analysis fom you on the human lenses and firmware! How do you
get doublet in there??? Haven't we got flexible single elements that can
dynamically adjust their shape for focus (and provide stereoscopic functions
as well)? The active 'pixels' set changes in low light too (rods and cones).
But we're drifting rather far off topic! By all means follow that up, maybe
with a new thread title?

2009/7/23 <LRZeitlin at aol.com>

> Geoff writes:
>
> "Mark - I think this design approach is going to lead to a whole new
> generation of light, small and highly capable lenses. The day may come when
> the highly corrected optics we so prize today will become anachronistic,
> like a mechanical watch. Will the fine Leica lens go the way of a Rolex?"
>
> Why not? This is nature's way. The human eye has a primitive optical
> system, basically an F3.5, 20mm FL non-achromat doublet. The sharp image
> circle is
> only about 3 mm in the center of the fovea. All those lovely, crisp, wide
> angle images you see in your brain are constructed by software processing.
> Here is what goes on in that complex computer in back of the eyeball. The
> projected image is encoded, focus is corrected, edges of objects are
> enhanced,
> colors are assigned to various portions of the image depending on which
> cells
> in the retina are activated, small image portions are stitched together as
> a function of eyeball position to form a whole percept, and an illusion of
> depth is created by the disparity of images from each eyeball. A pseudo
> image
> is created for blank spots (blind spot) in the retina. Further, geometric
> shapes are corrected so that they accord with experience. Objects viewed at
> a
> distance are made to appear larger. Colors constancy is maintained despite
> changes in the viewing light. And so on.
>
> Computer technology has reached the point where lens defects can be
> corrected in software better than in glass. Nature doesn't depend on
> perfect optics
> to provide a perfect image. Why should Leica?
>
> Mechanical Rolexii have a cult following. Just like Leicas.
>
> Larry Z
>
>
> **************
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>
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>



-- 
Cheers
Geoff
Alles was eine gute Kamera braucht / Everything a good camera needs:

http://gallery.leica-users.org/v/gh/
http://www.pbase.com/hoppyman


In reply to: Message from LRZeitlin at aol.com (LRZeitlin at aol.com) ([Leica] Software lens correction)