M42 part 2

[bomberbaz]

Ok so not added a load of data to the first M42 from the other day which can be seen first with the second one below.

I have tripled the data from 7 minutes to 21 minutes but as with adding more data you add more noise. This comes from an already immensely light polluted back garden.

All I have done is stretch and gradient removal, no star reduction carried out.

The biggest issue is gradient, it really is quite horrendous and this can be seen in the third image to show what I am dealing with. I have a hotel car part 50 yards to the right side of my house with a squillion watts of lighting illuminating it.

I remove part of the gradient in Siril and the rest in Gimp, however I lose image quality in doing so but I am improving, slowly. 

7 minutes

 21 minutes

 Gradient

 

[MartinB]

Yes that's quite a gradient.  The 7 minute image is looking good.  Have you tried GraXpert.  It is a free gradient removal tool which is supposed to be very good.

[AstroMuni]

On 14/02/2023 at 22:06, bomberbaz said:

I have tripled the data from 7 minutes to 21 minutes but as with adding more data you add more noise. This comes from an already immensely light polluted back garden.

Its looking good...you are correct about adding more noise, but the SNR should improve too. Unfortunately in this imaging game, I think we need to add lots more data to see significant differences in the quality of the image. 😞

@MartinB a version of Graxpert has been coded into Siril and it does a pretty good job of removing gradients IMO.