[Ross G]

Hello,

I have just started using a QHY8L ccd camera, having upgraded from a Canon 1000d.

Consequently, I have also started taking flat and bias frames.

The camera's first real test was 3 nights of imaging at Coonabarabran in March. It worked well and I have been processing and experimenting with the images as I learn.
I have noticed that applying flats and bias frames gives my images an unsatisfactory colour shift as compared to not using flats and bias frames. For example, my shots of the Horse Head Nebula have a magenta cast whereas without the flats and bias' the reds are red and look more natural.
When I looked at the histogram of the flat frames, they have 3 distinct humps.
Is this normal?
I used a light box to produce the flats.

Thank you.


Ross.