Preprocessing Issue

[Oscar71]

I have 10 luminance images (600 sec) and 5 of each of RGB (500sec) all binned 1x1. When I preprocess the whole image set the Luminance appears to work well but all the colours are very dark and granular. When I process the colours individually I get the error message 'No correlation between the master channel dark and target frames (channel 0)'. The colour data is a little under sampled but another image captured a month prior with the same exposure intervals did not cause any problems. Each unprocessed colour image looks OK when viewed as an individual frame.

[jkmorse]

what masters are you using for pre-processing.  If you are using both a bias and a dark, try just using the dark and see if that solves the problem.

[Oscar71]

Thanks for your feedback. I tried without bias and without a flat. Same error message.
I went on to try to integrate the image set even though I had this error message. The Luminance and red sets integrated satisfactorily but the blue and the green would not integrate. Both blue and green had very high rejection percentages irrespective of what rejection method I used. I also got the error message 'No convergence in MRS noise evaluation routine - using K-sigma noise estimate'.
If you have under sampled data can you get to the stage where the integration process will fail?

[jkmorse]

Any chance you can post a link to the data for people to look at?  That is the best way to analyze the problem you are having.  One issue you may be having, however, is one I have addressed elsewhere in the pre-processing system and that has to do with FITS incompatibilities that you can fix with input hints.  Take a look at this post to see if any of the suggestions help:

http://pixinsight.com/forum/index.php?topic=8021.msg52728#msg52728

Note though I talk about imports from MaximDL, it has happened to others with different software.

Hope that helps,

Jim