Archived posting to the Leica Users Group, 2012/03/04

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Subject: [Leica] S2 vs. 645D
From: benedenia at gmail.com (Marty Deveney)
Date: Mon, 5 Mar 2012 12:39:07 +1030
References: <CAF8hL-FNBLyfDsOVVujKmCgyj32zxApU=spJ2JpncxQ-uJMTCA@mail.gmail.com> <CB79599C.F3CC%chris@chriscrawfordphoto.com> <CAF8hL-G7zvEzVJY768BCHnH0-5rhtVZ+=zN454r3Givbvo43hQ@mail.gmail.com> <CA+=0raAd=VAEmUpqyx9jTXF92TzuDqD8_yE1jb+uGEsJzXT76A@mail.gmail.com>

On Mon, Mar 5, 2012 at 11:09 AM, mehrdad <msadat at gmail.com> wrote:
> notably lenses, there is not much around that can resolve 40 meg

I have no idea where these persistent ideas that we are approaching
the resolution of currently available lenses come from.  Maybe it's
because the finest set of lines on an MTF chart correpond to 40lp/mm,
but that's misinterpretation of MTF data.

The sensor of the S2 has a 45x30mm sesor, 7512 x 4992 pixels and has a
6?m pixel pitch.  The Pentax 645D has a 44x33mm sensor, 7264 x
5440pixels and also has a 6 micron pixel pitch.  These sensors resolve
about 60 lp/mm.

This is well within the capacity of good (but not exceptional) medium
format lenses.  Really good medium format lenses will already exceed
that wide open across the whole field.

It's also important that improving sensor resolution will produce an
observable improvement in image resolution until the lens resolution
drops to half that of the sensor.

The improvement is useful.  The lenses are good.

Marty


In reply to: Message from richard at richardmanphoto.com (Richard Man) ([Leica] S2 vs. 645D)
Message from chris at chriscrawfordphoto.com (Chris Crawford) ([Leica] S2 vs. 645D)
Message from richard at richardmanphoto.com (Richard Man) ([Leica] S2 vs. 645D)
Message from msadat at gmail.com (mehrdad) ([Leica] S2 vs. 645D)