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- From: jacobson@cello.hpl.hp.com (David Jacobson)
- Subject: Re: Resolution of Lens ???
- Message-ID: <1992Nov18.164258.8766@cello.hpl.hp.com>
- Date: Wed, 18 Nov 1992 16:42:58 GMT
- References: <Uf2JFiO00iV1M5dkha@andrew.cmu.edu> <Bxw69K.309@world.std.com>
- Organization: Hewlett-Packard Laboratories
- Lines: 27
-
- In article <Bxw69K.309@world.std.com> dp@world.std.com (Jeff DelPapa) writes:
- >When I have had lenses tested, they were used in projection - an
- >etched resolution test reticle was placed at the film plane, with a
- >collimated light source behind it (the reticle was a peice of
- >aluminized glass - it looked a whole lot like a mask from an IC shop).
- >That was projected onto a screen, with the distance varied to get it
- >all to fit. The person then examined the projected image to see what
- >the smallest clearly projected portion of the chart was. He could make
- >judgement about field flatness, chromatic aberration, flare, and
- >lens alignment in addition to resolution. No math or measurment was
- >required to come up with the resolution number - you just read off the
- >number next to the last clearly resolved pattern.
- >
- ><dp>
-
-
- I've got a question of the optics experts on the net. When you use a
- projection reticle like this the light going through one piece of the
- reticle and a neighboring piece will be coherent. (Well, coherent
- might not be the right word.) So there will be interference effects.
- But light from different points of a subject coming the other way will
- not have any iterference effects. How does this affect the results?
-
- -- David Jacobson
-
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-