adding more data to existing

[Ewan]

I have searched google but nothing found thats precise, i was wondering how i add data to subs already collected ?

Do i stack what i have ie 30 of M81 last night then stack what i get tonight (if any) then combine these 2 images or is it best to stack all the subs in one go.

Thanks for any help you can give

[ollypenrice]

Probably best to do a restack from scratch provided you have the same flats in operation. In my way of working that would nearly always be the case unless I were adding new data to an image from a long time ago.

If you don't have the same flats then you could make a new set of uncombined but calibrated lights (using the right flats as appropriate) and then stack those.

Since I often work in collaboration with other imagers or add data to much older pictures I end up stacking the stacks and this does seem to work well also.

Olly

[Ewan]

Excellent Olly thank you, didnt really think too much about it until last night, mount was tracking great after a reset & i managed 30 mins M82 & 45 mins M81, not much i know but its something & stars looked pretty round, got my guiding parts coming this week so another thing to learn.

[Freddie]

Ewan, in DSS, put the images from different nights into different groups (tabs at the bottom left of the main screen) You can also add the matching calibration frames this way.

[Ewan]

Thanks Freddie, i was pretty made up getting 90 sec subs with pretty good stars last night, then i saw m81 & m82 appear on my screen im sure neighbours heard me shout wow! :-).

Think i got setup balanced just right & resetting the mount may or may not have improved things bug i am so looking forward to trying guiding now, HutecAstro usb was dropped off today jyst waiting on finder guider adaptef.

Thanks guys for your help.