Quick question I should know the answer to

[Newforestgimp]

Hi All

I seem to be confusing myself lately & I should know this…

are calibration frames telescope specific ?

thank you

[fifeskies]

Yes , they compensate for telescope optics such as vignetting and dust on the lenses.

You should not move focus etc before taking the calibration frames as this would change the position of dust motes  relative to the sensor.

[teoria_del_big_bang]

For Flats it is as @fifeskies says they should be taken shortly after a session, and ideally for each session, with all the optics as they were for imaging, so no rotation of the camera, same focus position and separate flat for each filter used during the session.

But, darks can be done anytime and on any scope, in fact often the best wat to take darks is with the camera removed and covered in aluminium foil in a dark room to ensure no stray light hits the camera.
Darks only need to be taken pretty infrequently, most keep a darks library for 6 to 12 months before retaking them. So best to do a darks session and take all darks for every exposure lengths you think you are likely to use then no need for up to a year to do them again, make a good master dark for each exposure time you are likely to use and use them for the foreseeable future.

Steve

[Newforestgimp]

Thanks both,

that was what I thought but got in a muddle 😂 

thanks again

Andy