iraf.net

NUMBER:	147
MODULE:	ccdred.mkskycor ccdred.mkillumcor
SYSTEM:	V2.9
DATE:	Tue Apr 16 16:42:36 MST 1991
FROM:	valdes

BUG:	The CCDMEAN parameter computed by the task MKSKYCOR and MKILLUMCOR
	is computed incorrectly in the sense that it is smaller than the
	correct value by a small amount.  The last few lines of the image
	were not accumulated before dividing by the number of pixels in
	the output image.

STATUS:	This bug has been fixed for V2.10.  One workaround is to use
	yboxmin of 0.  The other workaround is to use IMSTATISTICS and
	HEDIT to compute and replace the correct value.  Failing to do so
	and then correcting images with CCDPROC will slightly change the
	data level which may be acceptable.