Tulip Nebula

[Paul Holdsworth]

Hi just thought I'd post my start on the tulip nebula. This is just 2.5 hours of 5 min subs from the other night so it's a bit soft until I get more data. There does appear to be a fair amount of signal for such a short integration so guessing it must be a fairly bright target. Not sure why but for some reason I had massive star halos around quite a few stars but this was first time out since the middle of March so maybe I need to go around everything and give it a good old tighten! However  I do think the L extreme filter does seem to suffer more from halos than my L enhance. Anyway it was just nice to be out imaging again and it seemed ages since I posted anything so here's a work in progress of the tulip nebula

Cheers

Paul

[Adreneline]

Hi Paul,

This is a target I keep meaning to have a go at - great framing and colours, and no evidence of halos but there is something a little tricky going on with the stars.

You don't make any mention of the processing processes so not sure what might have introduced these sort of artefacts.

I have seen Topaz DeNoise do strange things like this but not sure if that applies here.

HTH

Adrian

[Paul Holdsworth]

Thanks Adrian, I processed this pretty much entirely in pixinsight. I did the usual crop, automatic background extraction, colour calibration, noise exterminator, soft stretch, star exterminator , star reduction, split the channels, pixel math for a fake sulphur channel,  re combined as LRGB, Colour masks for stretching individual colours, unsharpmask for sharpening then over into light room for a bit of finishing. 

Out of the processes that has introduced the artefacts I would guess it's the new noise exterminator script that I've not used correctly though I have to say I'm impressed with its noise reduction capabilities.......of course it could be star reduction that's caused it. Thanks for your help Adrian and will definitely play around with some settings when I put together a final image for this one.

Many thanks

Paul    

[Sterrenland]

Love the detail and colour...great image.

[The Lazy Astronomer]

Very nice for just a couple of hours - lovely crisp detail on the dark nebula in the tulip. One thing missing though, is the bowshock from Cygnus X-1, which should appear just to the right of the tulip itself; that region looks almost like it's been clone stamped away?

[Paul Holdsworth]

Thanks guys. Yes busted with the clone stamp !! It was just one of those images where I seemed to have halos everywhere so tried to rescue the image with the clone stamp.......obviously got a bit carried away ! I definitely think there's an issue with the L xtreme filter paired with my 294 mc pro regarding halos which doesn't even contain itself to just the brightest stars. I guess it's possible I didn't get a good copy of the filter. 

thanks for taking the time to comment. 

Cheers Paul 

[Adreneline]

1 hour ago, Paul Holdsworth said:

I would guess it's the new noise exterminator script that I've not used correctly though I have to say I'm impressed with its noise reduction capabilities.......of course it could be star reduction that's caused it.

Hello Paul.

I think it unlikely that the new NoiseX has done this - I only used it through the trial period but didn't notice anything odd going on.

For what it is worth I tend to perform whatever initial noise reduction is required (my preference is nearly always MLT with an L mask - four layers) and then make a clone of the noise reduced image. I strip the stars from the original and process that to the extent I think is right for the target. With the clone I use EZ Soft Stretch on the image followed by MMT to reduce the stars a tad and then strip the stars out using Starnet2 to combine back with the (now starless but fully processed) original. When combining back I usually just do a straight addition in PixelMath although I was recently given this formula ~(~starless*~stars) which produces slightly 'dimmer' stars compared with a straight addition; modifying to this ~(~starless*~(1.2*stars)) will up the star brightness a tad.

I have found putting stars back is a real challenge - it is loads more difficult that just whipping them out with StarXterminator or Starnet2 that is for sure!

I hope this helps/is of interest.

Adrian

 

[Paul Holdsworth]

Thanks Adrian will definitely give this a try for sure.

Cheers

Paul