Archived posting to the Leica Users Group, 2008/03/07

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Subject: [Leica] No M9 in the near future
From: wildlightphoto at earthlink.net (wildlightphoto@earthlink.net)
Date: Fri Mar 7 15:59:27 2008

Mark Rabiner <mark@rabinergroup.com> wrote:

> You've got Canon and Nikon shooters shooting full frame.
> But not Leica?
>
> To me that does not add up.

The difference in angle of incidence between an SLR lens (which needs to
clear the reflex mirror) and the RF lens, particularly a wide RF lens, is
what causes the problems.

The distance from the exit pupil of the M wides is much closer to the
sensor than on the C or N SLR bodies, simply because of the geometry of the
light-tight boxes.  With existing commercially-available sensor technology,
the angle of incidence resulting from the shorter exit pupil-to-sensor
distance causes problems including light fall-off and uneven effectiveness
of sensor cover glass filters (i.e., IR or UV blocking filters).

It's theoretically possible to make a sensor with micro lenses that would
compensate perfectly for the light fall-off for a particular exit pupil
distance, but this would not fix the uneven UV/IR filtering nor would it
work with other exit pupil distances.

It's also possible to make lenses to fit the RF camera that have a much
greater exit pupil distance, but these would be as large and heavy as a
comparable SLR lens, blocking the viewfinder and generally defeating much
of the purpose of using an RF camera.

Leica has figured out a way to make the system work.  It's not ideal but it
allows the use of tiny superb lenses to make super-sharp and colorful
pictures.  Until sensor technology improves it's likely it's either the M8
or a much bigger dSLR.

Doug Herr
Sacramento
http://www.wildlightphoto.com

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