In a message dated 6/22/2007 2:01:14 PM Central Daylight Time,
ayiomami@... writes:

Because the large circles move from master image to master image, we
can rule out any possible particles on the CCD window which leaves (?)
the filters themselves.

I have looked very carefully at the filters and even tried cleaning
them but the result remains the same. The circles also seem very big
to be dust motes. I am wondering if the problem is at source during
manufacture?

Only way to know is to remove a filter and shoot through the air itself.
Possibly the dust is on the field flattener lens or telecompressor. Yes, the
further away from the film plane, the larger the dark circles will be. However,
once you get to the objective lens itself, you can have all kinds of dust or even
large central obstruction, and nothing at all will appear on the image - but
of course you knew that, yes?

Rolando


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