FAQ: “No images to combine” (COMBINE, FLATCOMBINE, ZEROCOMBINE, etc.)

Frank Valdes wrote on Mar 17, 1998

Q:  I would like to know the nature of the following problem,
I'm trying to combine bias, skyflats, etc, and I get the error messages
ERROR on line 46: No images to combine

when I execute zerocombine or flatcombine, but the images are there!!!
I did everything but with no success.
Could you tell me what I'm doing wrong?


A: This message always means that image types of the input images do not
match the "ccdtype" parameter; i.e. zerocombine will by default only
look for zero images and flatcombine will only look for flat images.
If your data does not have the information to identify the type of
image then you should set 'ccdtype=""'; i.e. no value.  Then these
tasks will use whatever images you give them.  To determine what
image types the CCDRED package things you have you can use CCDLIST.
For more on this type "phelp ccdtypes".

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Chris Dolan wrote on Mar 18, 1998

>Q:  I would like to know the nature of the following problem,
>I'm trying to combine bias, skyflats, etc, and I get the error messages
>ERROR on line 46: No images to combine
>
>when I execute zerocombine or flatcombine, but the images are there!!!
>I did everything but with no success.
>Could you tell me what I'm doing wrong?

When I've seen this error it has always been because I haven't run
"setinstrument" properly.  If this isn't set for, e.g., "kpnoheaders"
then the various CCDRED routines can't interpret the CCDTYPE
parameter, even though it is clearly in the image header.

Chris Dolan

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Last post on Mar 18, 1998