Question referrering to Deep Sky Stacker and Flats

[astrobena 7]

Hey everyone,

Over the past few days i've been gathering data on M31 due to the battery not lasting long and andomeda dissapearing behind a tree, therefore the mulitple imaging sessions. So far i've been out and me being me, only took dark, bias and light frames for the first 2 sessions but for the last one i also included flats... (The lights all have very slightly different settings cause i have been experimenting slightly... that being 45sec @ ISO 400, 45sec @ ISO 200 and 50sec @ ISO 100) Now DSS assinged all the correct bias and dark frames to the corresponding light frames but because i only have flats for my last imaging session it applied those to all the different light frames and not just to the last set...(and due to me moving the telescope / taking the camera off, the dust spots have obviously been moving around and that therefor dont work at all for the other light frames...) So my question: Is there any way in DSS to apply flats to only one set of light frames and if not are there any other apps with which i can do this with?

Many Thanks!

[almcl 727]

I think the answer to your question is 'yes'. 

If you place the flat frames in the tab  (I assume you used the different tabs for the  differing exposures?) with just the lights and darks for that exposure, they should only be applied to that set of lights. 

You don't say what camera you are using, but mixing different ISO and exposure lengths in the same stack can be problematic - no harm in experimenting though to see what works best, but you might want to try stacking the various different exposures separately to see the results?

[astrobena 7]

43 minutes ago, almcl said:

I think the answer to your question is 'yes'. 

If you place the flat frames in the tab  (I assume you used the different tabs for the  differing exposures?) with just the lights and darks for that exposure, they should only be applied to that set of lights. 

You don't say what camera you are using, but mixing different ISO and exposure lengths in the same stack can be problematic - no harm in experimenting though to see what works best, but you might want to try stacking the various different exposures separately to see the results?

Ahh ok, ive used the tabs and at first even that didnt work but that was because i put the images from the imaging session with all 4 frames into the Main group not one of the other ones... All sorted now, cheers!!

I use the canon eos 400D and ill probably settle on 50 sec with ISO 200 from now on, that seems to be best (i know thats again different from all the others but the 50 sec ISO 100 was slightly therefor the ISO bumb up)

Thanks again!