JCO,
In this case of 2mm between the rear element and the sensor, I'd suggest
you think of the rear element (or group) of the R-1 as a meniscus with a
curved surface toward the other elements, acting as a focus plane for the
rest of the lens + a flat surface toward the sensor, for conveying the image
perpendicular on the sensor. Just my idea.
Dario
----- Original Message -----
From: "J. C. O'Connell" <[EMAIL PROTECTED]>
To: <pentax-discuss@pdml.net>
Sent: Friday, September 09, 2005 7:35 PM
Subject: RE: First non DSLR digicam with 10MP APS sensor- contradiction
wrong, the closer the rear element. the more that forces
greater NON perpendicular incidence angles
to the corners of the sensor. It order to
approximate true perpendicular incidence, the
rear element has to move away infinitly from
the sensor. Total opposite of what you just posted.
jco
-----Original Message-----
From: Adam Maas [mailto:[EMAIL PROTECTED]
Sent: Friday, September 09, 2005 1:13 PM
To: pentax-discuss@pdml.net
Subject: Re: First non DSLR digicam with 10MP APS sensor- contradiction
Putting the rear element closer to the sensor allows you to have a
perpendicular light path to the sensor without going to an extreme
retrofocus design for wide angles. This allows a simplified lens design
for equivalent length and zoom range. The Light path only needs to be
perpendicular from the last element to the sensor, which is
understandably difficult with an SLR and it's relatively long register
necessitated by the mirror box. That is one reason that C*n*n developed
their EF-S mount, which allows the lens to protrude further into the
mirror box, making the 10-22 easier to design.
-Adam
J. C. O'Connell wrote:
Isnt is a contradiction that the lens is CLOSER
to the sensor and its an improvement because that
means the light it hitting the corners of the sensor
at a GREATER angle away from perpendicular which
is BAD (perpendicular being ideal)?
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J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com
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