as you say, the plot indeed thickens, but I think I have now worked out what was going on....
2 bugs
1) The code to convert the flat frame to mono has not worked for RAW mode cameras for erm... cough cough... an embarrasingly long time. From the source code history it looks like I was changing to make the mono conversion work in a slightly nicer way and ended up commenting out the line that actually did the conversion (perhaps trying to track down an issue) and forgot to put it back
![Embarrassed :oops:](./images/smilies/icon_redface.gif)
2) The problem that I found and fixed previously with the dark subtraction in RAW mode was still happening when subtracting dark/bias frames for flats - this was because the RAW flat frame gets saved as FITS, then reloaded. The reload doesn't pick up on the fact that the frame was RAW and loads it as a mono frame. This wouldn't matter at all except for the dark subtraction hot pixel code which wrongly thinks it can steal values from neighbouring pixels rather than the one two to the left.
I think I have now fixed both of those - please have a play with this version and see if you agree : https://d.sharpcap.co.uk/download.html? ... p;arch=x64
If I had a 'SharpCap Chief Bug Finder' hat, I would be posting it to you right now
![Wink ;)](./images/smilies/icon_e_wink.gif)
cheers,
Robin