M42 - 2023 edition - made a start WIP

[Bob Dobber]

A bit of an afterthought, slewing to this old favourite at the end of a Heart Nebula run, but this is 3h46m of 30s LRGB subs on Messier 42.

 

 

 

[+Bino-viewer]

Really nice, and i like the wide angle view of it, with 'the running man' which i think better presents all the nebulosity and stuff.

 

Are 30s subs better here, and a good way to prevent over-exposing the core ?

[Bob Dobber]

49 minutes ago, Bino-viewer said:

Really nice, and i like the wide angle view of it, with 'the running man' which i think better presents all the nebulosity and stuff.

 

Are 30s subs better here, and a good way to prevent over-exposing the core ?

 

Thanks. Although that huge blue halo/thing on the bottom right wasn't very obvious on my processing screen. But on my phone, whew!!

 

And yes, 30s subs to try and calm down the core. Still a little blown even at that exposure length.

[+Bino-viewer]

Am i correct in assuming that 113 seperate subs for each channel ?

 

That seems a lot. Forgiving my lack of knowledge here (i'm only a novice where imaging is concerned) I was always under the impression

that once you'd taken 30 or so 30 second subs it was a bit of a case of diminishing returns adding lots more ?

[Bob Dobber]

12 minutes ago, Bino-viewer said:

Am i correct in assuming that 113 seperate subs for each channel ?

 

That seems a lot. Forgiving my lack of knowledge here (i'm only a novice where imaging is concerned) I was always under the impression

that once you'd taken 30 or so 30 second subs it was a bit of a case of diminishing returns adding lots more ?

 

It's 453 individual subs. I'm sure at some point there will be diminishing returns, but at only 3h46m of data, I doubt I'm anywhere near it yet!

[+Glafnazur]

2 hours ago, Bob Dobber said:

 

Thanks. Although that huge blue halo/thing on the bottom right wasn't very obvious on my processing screen. But on my phone, whew!!

 

And yes, 30s subs to try and calm down the core. Still a little blown even at that exposure length.

Nice image Rob. Could you take some shorter exposures of the core and merge them?

[Bob Dobber]

1 hour ago, Glafnazur said:

Nice image Rob. Could you take some shorter exposures of the core and merge them?

 

I probably _could_ - whether I can be bothered is another matter 😄 

[Clive]

4 hours ago, Bob Dobber said:

 

It's 453 individual subs. I'm sure at some point there will be diminishing returns, but at only 3h46m of data, I doubt I'm anywhere near it yet!

What's the background noise of your image?  Once the background noise of the image becomes insignificant then there is no point of adding any more images.  The point of stacking is just to increase the SNR, once the RMS backgound noise is just a few ADU then little visible gain will be obtained by stacking more images, especially if the final image is saved as a JPEG.

[Bob Dobber]

37 minutes ago, Clive said:

What's the background noise of your image?  Once the background noise of the image becomes insignificant then there is no point of adding any more images.  The point of stacking is just to increase the SNR, once the RMS backgound noise is just a few ADU then little visible gain will be obtained by stacking more images, especially if the final image is saved as a JPEG.

 

Indeed, however with such short subs, said signal, particularly of the dust around the periphery of the image, is likely to be very weak. At present that detail is mainly presenting as noise I think, so if I were to want to really nail this image (and I'm actually not that bothered) I would need to keep going until I see improvement there. I remember my Iris Nebula image from about a year ago, I kept going collecting data and could see the dark dusty areas coming out more and more vividly.