"Roland Roberts" wrote in message
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"rl" == Robin Leadbeater writes:

[...]
rl These Ex view Had chips are not renowned for their low noise a
rl ambient temperatures.

Hmmm, while a webcam based imager is unlikely to be anywhere close to
optimal, I would have sworn that I heard Ron Wodaski say that the Ex
View HAD chips where designed to almost not need dark frames during
Saturdays' NEAF conference on CCD imaging. I'm wondering if while
scribbling notes I missed some context....

roland
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Hi Roland,

I think the temperature is the key. AFAIK, except for the DSI, all ExView
chipped long exposure cameras are cooled, even the low end 8bit models like
the video camera based SAC8. Even the uncooled integrating video cameras
like the Ex View based Mintron etc start to struggle against noise beyond a
few seconds exposures.

There are some CCDs which give reasonable performance at ambient eg the
ICX424AL (HAD based but not ExView) as used in the webcam based 8 bit ATIK
2HS, but not in an hour exposure.

BTW I do not know offhand of any webcam based cameras using Ex View
technology. I think all the ExView chips currently manufactured are designed
for Video rather than webcam applications.

Robin