Posted by
Joachim Wesner on
Jul 18, 2006; 4:47pm
URL: http://imagej.273.s1.nabble.com/Optical-artefact-removal-tp3702076p3702083.html
Hi all,
>It is right that this is a specific coolpix artefact, it is present
>for models after CP-995 (4500, 5000) It is due to the photosites size
>(usually for digital cameras the improvements for general
>photography are bad things for microscope microphotography).
Hmm, are you referring to some kind of moire effect? However, I could not
understand
how this should show up on a presumed homogeneous (resp. non-periodic)
background!?
As I understand they are using non-infinity objectives in some kind of
infinity position,
I would assume (the order of this effect depends greatly on the focal
length of the objctive used)
that they need to defocus so much that a normally unnoticed (becaused
totally out of focus) internal
reflex becomes near focus and noticeable, maybe this is even a bad
coincidence with the reflection
from the "cover glass" (or whatever, I don´t know the layout of coolpix
cameras) in front of the chip,
so it might disappear with other cameras, because they have that glass in
another position!
Joachim
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