Where did the stars go??

[hornedreaper33]

Hey all,

I took some really rough images of M42 the other night, alignment and focus was by eye, heavily light polluted, no calibration frames and I have a dusty corrector plate. However, this was the first time I have shot a deep sky object and for how rough it was I was pleased, see attached.

I watched a lot of DSS tutorial videos last night and I decided to stack the 16 images I have just to see what I get. Now, I am under no delusions as to the expected quality of the final image however, stacking made all the stars vanish and the overall quality of the image was less that that of a single frame. Any suggestions? I do not have an example image saved, sorry.

Thank you.

[vlaiv]

You should save result of stack and import into software for processing and do some curves / levels on it.

"Raw" stacked image has large dynamic range and it will appear almost black with very few stars - that is because signal hides in "shadows" - it is very faint compared to stars and you need to adjust curves of your image (or exposure) to bring it to visible range.

Mind you, it can be what I've written above, but it can also be some problem with stacking - we can't know until you either try above yourself or post stack for inspection

[happy-kat]

GIMP is a free editing software if you don't have any already.

[hornedreaper33]

Thanks for the quick replies! I was opening the stacked image in Registax to play with the exposure and the wavelets etc. Still working on understanding what it is I'm actually changing. I will have another go and post something up.