How to tell if I can image something I can 'see' -nina

[Ratlet]

I've been playing around getting Nina configured and I think I've got everything working as intended.

I'm very impressed with the sky atlas and the framing guide.  There seems to be a huge number of potential objects to image, most of which I've never heard of!  The ability to filter by size is very useful to decide what would look good for a given focal length

My question is, is there away to figure out what would be a reasonable object to capture with a given scope based on its brightness?  Is it simply a case of the fainter it is the more data you will need?  Are there guidelines for what works well?  I'm only using a 200mm telephoto with a 50mm aperture so there isn't going to be a huge amount of aperture to play with. 

There are lots of objects up there that look really nice, but I'm not sure if trying to capture them would b e worthwhile as they might be too faint, especially for a noob.

[Astro Noodles]

1 hour ago, Ratlet said:

I've been playing around getting Nina configured and I think I've got everything working as intended.

I'm very impressed with the sky atlas and the framing guide.  There seems to be a huge number of potential objects to image, most of which I've never heard of!  The ability to filter by size is very useful to decide what would look good for a given focal length

My question is, is there away to figure out what would be a reasonable object to capture with a given scope based on its brightness?  Is it simply a case of the fainter it is the more data you will need?  Are there guidelines for what works well?  I'm only using a 200mm telephoto with a 50mm aperture so there isn't going to be a huge amount of aperture to play with. 

There are lots of objects up there that look really nice, but I'm not sure if trying to capture them would b e worthwhile as they might be too faint, especially for a noob.

But that's part of the fun of it.😄 You need to try it out and see what you get. There are certain things - Orion nebula, Andromeda, Cygnus loop etc which would frame up well in a 200mm lens. Most things need a lot of integration time, several hours. Tiny objects like the Crab nebula, most galaxies etc are not really worth taking with 200mm as you won't have enough resolution to blow them up.

[Astro Noodles]

As an example, using my equipment, this is how the Crab nebula would look at 200mm

Whereas Andromeda galaxy would frame up like this.

Although Andromeda is very faint away from the central core and will need many hours of integration time.

[Ratlet]

9 minutes ago, Astro Noodles said:

As an example, using my equipment, this is how the Crab nebula would look at 200mm

Whereas Andromeda galaxy would frame up like this.

Although Andromeda is very faint away from the central core and will need many hours of integration time.

It's the faintness that worries me lol.  Nina has a tool for framing which is great for eliminating the too small (I was surprised by how large a lot of these things are though!).

So fainter simply means longer total integration?  That makes absolute sense lol.  I guess for me I was thinking 'it can't be that easy, I must be missing something lol'.

Now to wait for some proper darkness.  Good timing to get into astrophotography lol.  There is always the moon at least!

[Astro Noodles]

I find that capturing fainter objects depends how good your signal to noise ratio is. With a good signal to noise ratio you can stretch out the faint details in processing.

 

[sterec]

See how easy a Magnitude 8-10 object, say,  is to capture with your proposed setup.  Stellarium would give you an idea then of what is available.

[ONIKKINEN]

Brightness of the target is a decent metric, but only if taken into consideration with its size - for example M101 is brighter than M51 at mag 7.9 compared to mag 8.4 when considering their total brightness over the entire object, but M101 is much bigger in angular diameter so that light is spread across more pixels = its actually fainter! (by a huge margin).

Cant remember off the top of my head if NINA has surface brightness in magnitudes per square arc-second in its sky atlas, but the PC downloadable version of stellarium does.

What surface brightness you can image with a reasonable integration will depend on your gear and i wont guess where the limit is but once you image a target with a suface brightness of X you know you can image all the other targets with similar or better surface brightnesses.

And framing obviously is important. I dont think the crab would turn out that well with 200mm fl and 50mm aperture.