Archived posting to the Leica Users Group, 2001/07/21

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Subject: RE: [Leica] digital M
From: "Austin Franklin" <darkroom@ix.netcom.com>
Date: Sat, 21 Jul 2001 15:22:08 -0400

> > The only thing that worries me is that Leica may have to re-design their
> > optics (at least wide M lenses) to make the best of the 24*36 mm (>6 MP)
> > CCDs. Those new lenses should be bigger and heavier, because CCDs prefer
> > perpendicular light rays. Some CCD experts can clarify this issue.

> Not sure i believe in "digital glass." I think you just make the
> best lens possible.
> I think most of that stuff just has to do with a specific coverage.

I do believe this can be a real issue with wide lenses.  The CCD sensor
elements are going to be recessed (tough ever so slightly) and "bounded"
between sensor elements and given that the light rays from wide angle lenses
are more off axis than longer lenses...the amount of light getting to the
off-axis sensors could decrease as the distance from center increases.

It don't know at what angle this would have an effect (the sensor specs
should give some information on this I would expect), or if this can be
corrected by a re-design of the optics...but if sensors are designed with
this possible issue in mind (or it ends up being a non-issue...but is
certainly something a designer should at least think about), I think we
should all be fine ;-)

I'll take a look at some of the sensor specs I have and see what they give
for off-axis sensitivity or what ever they may call it.

Replies: Reply from "Mxsmanic" <mxsmanic@hotmail.com> (Re: [Leica] digital M)