T3D Re: T3D Re: Iris placement

[P.J.Homer@xxxxxxxxxxxxx (Peter Homer)]

William Carter wrote

>The duliable John B. writes:
>> If you don't want vignetting when you stop down,
>>you put the iris where the chief ray crosses the optic axis.

I dont recal seeing this originaly and dont have any record of it to refer
to further.

>When photographing through the eyepiece of an existing optical system, for
>instance a microscope, would one be creating an aperture stop where the exit
>pupil of the ocular coincides with the entrance pupil of the camera lens???

Perhaps William Carter has been wondering as I have about the possibilities
of using stereo cameras without removeable lenses on stereo and biocular
microscopes . Perhaps even trying to use the iris to stop down and improve
depth of field with some loss of resolution. The only  thing I have actualy
taken like this was in 2D of a fibre using an Olympus OM2 with 3.5 macro
lens attatched through a Watson system 70 microscope. I canot recal if I
used  the full f 3.5 but it probably was ,using aperture selective auto.
There was a slight vignetting of the corners.   P.J.Homer



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End of TECH-3D Digest 234
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