StarTools

Hello all

when stacking frames in DSS, i am not sure how to select good frames or discart bad ones.
Say for instance that during the image session some clouds crossed the area I am imaging...
what parameters I should check in DSS to select the frames? As sometimes I end up with
images with a lot of gradient, even though some individual frames are OK.
Since when I load the files in DSS they all look quite plain... how do I discart bad ones?

Thank you! ^^

Carles R.

By no means an expert in DSS but here are some of the things I've found helpful.

Adjust the image slider at top right to best show the details (you probably already do this):
It may also be helpful to move the end stops to increase contrast (neither of these affect the final image but they may make judging individual subs easier):
Then use the columns. Clicking in the column title will order the files either highest first or lowest first. I usually start with the score, and have a look at deleting or removing from the list any that are much lower than the others. Also have a look at FWHM, no of stars and Sky background. A rising sky background coupled with falling numbers of stars may indicate cloud (or dew) whereas big FWHM might show a guiding problem. Again organising the sub by score and having a look at the worst ones with a view to removing them can help improve the final stack.

Almcl thank you!

That was very helpful indeed

I did use the sliders, but didn't see any difference in images, and the "Score tab" too but even selecting the best ones it comes out "wrong" sometimes
I didn't know how to interpret the FWM and sky background values, thanks a lot for the tip! I will try it right away! ^^

Regards

Carles.

also set your best or preferred frame as the reference frame

happy-kat wrote: ↑Wed Sep 30, 2020 6:41 pm also set your best or preferred frame as the reference frame

Thank you Happy-kat!
As in the highest score one? Does this get better results than without reference frame?

Carles

If you high light the highest score and right click , set as reference frame also you will see a settings box before stacking you can set best percentage use this to suit say best 80% or whatever suits you .

Regards Dave

Carles wrote: ↑Wed Sep 30, 2020 6:50 pm As in the highest score one? Does this get better results than without reference frame?

particularly useful if building a mosaic as you control the frame the other frames are stacked to in that mosaic portion.