Orions Sword - and where has the noise gone?

[Stub Mandrel]

I'm increasingly convinced that noise in my images is closely related to transparency. When my background is bright, my subs are noisier.

This particular image came out almost noise free, only the gentlest touch of noise reduction.

Very happy with the Skywatcher ED 66 element, no star bloat or haloes at all.

 

 

[saac]

Neil that is a lovely image; I think the colour balance and framing are excellent, really pleasing.    

Jim 

[Hallingskies]

Haze = noise, no doubt.  I even posted a “show us your subs” thread because of a run of really noisy subs, which then magically cleared in our recent run of clear skies.  I thought I had a dodgy camera, but it just turned out to be dodgy skies.

[Scooot]

Very nice Neil. Smashing image.  

[ollypenrice]

Haze does indeed equal noise but your black point is very tight as presented so I think you must have clipped both noise and signal here. If you let in more noise I think you'd let a lot more faint signal in with it.

Olly

[Stub Mandrel]

10 hours ago, ollypenrice said:

Haze does indeed equal noise but your black point is very tight as presented so I think you must have clipped both noise and signal here. If you let in more noise I think you'd let a lot more faint signal in with it.

Olly

The problem I had wasn't noise, it was some dust blobs that moved before I took my flats (they actually moved during the session so I'm not sure what was happening...)

In part I  used your 'hockey stick curve' technique to help get rid of them which smooths the background a lot but I was careful not to lose the edges of the nebulosity. I may have overdone it a bit.

But compare extracts from stacks taken with the same rig two nights apart, both  after a first stretch in FITS liberator