Calibration Query

[groberts]

In the absence of clear skies for some months, I have obtained subs and calibration frames from another party for processing but wanted to check a couple of points:

1. There a darks at 25C and 15C - can these be processed together to produce a dark master or should the temperatures be processed separately?
2. There are Flat_Darks, are these the same as Dark_Flats?  I understand dark flats and have taken them myself at the corresponding time for the respective filter flats, but these are a all at 5sec, much longer exposures than I'd expect.     

The camera is a QSI683-WSG8.

Graham

 

Edited February 2, 2021 by groberts

[vlaiv]

1) separate darks for separate temperature lights - create two masters and use according to temperature of lights

2) same

Flat exposure can sometimes be rather long - if flat panel is not very strong or sky flats are taken or some other method employed that does not produce strong light. Narrow band filters usually have significantly longer flat exposure due to fact that they only let in fraction of the spectrum and in the end - cameras with mechanical shutter benefit from much longer flats to avoid gradient from moving shutter.

[groberts]

Thanks Vlaiv, as I thought but just checking.

Graham