Flat Field Frames Questions

[cjs998]

I'm imaging using an Atik 383L+ mono CCD camera with LRGB filters. And have questions:

1) I'm assuming the flat frames are shot at the same temperature as the light frame temperature, -20degC in my case. Correct?
2) Do I need to shoot flat frames with each of the filters?
3) Assuming I do, what is the post-processing work flow for those?

I'm following Vicent Peris's "Master Calibration Frames: Acquisition and Processing" tutorial but it does go into this detail.

Chris

[Zocky]

You have 3 types of calibration frames.
Dark - it must be taken with the same temperature and same exposure time.
Bias - it is taken with shortest exposure time, regardless of temperature.
Flat - it is taken using light panel or evenly illuminated surface, regardless of temperature.

If your filters are absolutely clean, than you don`t have to take flat for each filter.

When you acquire all of the calibration frames, you have to make master frames by using ImageIntegration. When you make master frames, then you use them in ImageCalibration to calibrate your Light frames.

[oldwexi]

Using a QHY8 and a ST11K my experience gives the following answers to your questions:
1) Yes, thats very important especially with the SBIG ST11K - the flat do not fit if the temperature is different to the lights and
    I am sure therefore its ímportant fore other CCDs too.
2) Yes, because the CCDs have different sensitivity for different Colors, Flat
    for each filter is important!
3) Postprocessing for Masterflat is very simple.
    Calibrate each single flat with the MasterBias.
    Integrate the calibrated flats to a MasterFlat.

Gerald