Hi,
I'm having a spot of bother with the task noao.digiphot.daophot.nstar, and I hope somebody will be able to help me. The basic probmlem is that in the course of performing photometry, having run the daofind, phot, pstselect, and psf tasks i get to the nstar task. I pass it all the relevant arguments and it returns the error:

ERROR: Image header parameter not found (FUNCTION)

I assume, and i could most certainly be wrong, that this means there is a keyword and value missing from the image header file called FUNCTION.
The background, in case it's necessary, to this problem is that the images I'm working on are ACS images from the HST which have already had wfits, imshift, imcombine, imcopy (to do some cropping), performed on them. I've tried looking on the internet for a meaning for the keyword function in the hope that I could furnish the header file myself but as you can imagine the word function crops up quite a bit, even when I limit it down by including nstar in the search parameters.
Has anybody had similar problems? It's seems like there should be a simple solution but it has me confounded. Please let me know if anyone has any advice.

Yours hopefuly,

Brian Field
University College Cork,
Ireland

Try some of the suggestions given in http://iraf.net/phpBB2/viewtopic.php?t=82746. Post back if you're still having problems.

Cheers,
-Mike

Thanks very much, that's all sorted.

Brian.