about the exposure time of dark in ccdproc of ccdred

Poon Helen wrote on Feb 20, 2009

I combined 10 dark images of 30 seconds. If the ccd images of my target have exposure times of 50 seconds or 80 seconds or whatever, when I subtract the dark from these images, iraf will subtract the dark of the original 30 seconds from them or iraf will create a dark of the same exposure time as the ccd images and then subtract it from them?

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Mike Fitzpatrick wrote on Feb 20, 2009

See the CCDPROC help pages, dark exposures and other calibration data are scaled so they have the same exposure time.

-Mike

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Poon Helen wrote on Feb 20, 2009

sorry, I couldn't locate the ccdproc help pages. Is it in iraf or in this website?

I tried http://iraf.net/faqman/index.php?op=cat&c=3 but couldn't find it.

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Mike Fitzpatrick wrote on Feb 20, 2009

To read the help page, type the task name into the banner bar above and hit <cr>, In this particular case, see http://iraf.net/faqman/index.php?op=cat&c=3

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Last post on Feb 20, 2009