Stacking images from different nights

[Chefgage]

I know the question of stacking images from different nights has been asked many times before. I know how to set up DSS to do this. But my question is a bit more spefic and I couldn't see an answer to it.

I have a set of images of the eastern veil nebula taken under 95% moon lit sky. The images are narrowband (l-enhance filter). I would like to take more images over different nights to build up the total image time as we are a bit limited at the moment regards how long it is 'dark' for (UK).

Is it worth using data from moon lit nights along with data from say when the moon is not out. 

A quick process of just 40 minutes under a 95% moon did show a fair bit of detail.

[Freddie]

When you have the new images without the moon just do a quick test. A stack with the originals and a stack without. You can then decide for yourself. It's not as if you will waste any time as you already have the shots that will potentially be discarded.

[The Lazy Astronomer]

@Freddie beat me to it!

You'll likely get varying opinions on this, mine is as above - 'suck it and see' as my old boss used to say.

[Chefgage]

15 minutes ago, Freddie said:

When you have the new images without the moon just do a quick test. A stack with the originals and a stack without. You can then decide for yourself. It's not as if you will waste any time as you already have the shots that will potentially be discarded.

That sounds like sound advice. I will do just that. 

[Chefgage]

11 minutes ago, The Lazy Astronomer said:

@Freddie beat me to it!

You'll likely get varying opinions on this, mine is as above - 'suck it and see' as my old boss used to say.

In my mind I was sort of thinking that data from a poor seeing (moon lit) night added to a good seeing night (no moon) would still improve the image (increase the SNR). So poor data is better than no extra data.  But that could of course be that I am sleepy after a big fish and chip tea!

[The Lazy Astronomer]

3 minutes ago, Chefgage said:

So poor data is better than no extra data.

And this is precisely where the difference of opinion will be. One school of thought will champion high quality of data, the other, sheer quantity of data. 

I've seen real world tests which conclude quantity wins out, but equally I've seen other tests which conclude the opposite. l don't think it's necessarily a question with a simple answer. 

[david_taurus83]

In the UK we simply haven't got the luxury of cherry picking data like this. Unless your imaging close to the moon I'd say stack them and see. 

[Freddie]

2 hours ago, Chefgage said:

In my mind I was sort of thinking that data from a poor seeing (moon lit) night added to a good seeing night (no moon) would still improve the image (increase the SNR). So poor data is better than no extra data.  But that could of course be that I am sleepy after a big fish and chip tea!

Moon light does not affect seeing, turbulence in the atmosphere is what affects seeing. I think you have your terminology a bit mixed up.

[Chefgage]

Thanks everyone for the replies.

[Chefgage]

11 hours ago, david_taurus83 said:

In the UK we simply haven't got the luxury of cherry picking data like this. Unless your imaging close to the moon I'd say stack them and see. 

That is what I was thinking. To get a new moon and clear skies to line up is very rare.