NGC 2237 The Rosette Nebula (Hα/OIII/SII)

[Euan]

I've been tinkering with full narrowband on and off for ages, but never managed to get anything resembling an image. I don't know if it's just now that I've moved to a 100mm scope, but things seem to be falling into place now.

So here is my first ever full narrowband image, to say I'm chuffed with this would be an understatement. There's still a lot of bits to figure out mind you, like purple haloing and the purple sky background.

I might add another hour each to OIII and SII to see if I can get it a bit smoother and be able to use HDR on it.

Camera: Atik 383L+ Mono with Baader 1.25" Hα / OIII / SII

Scope: Borg 101EDII with 0.85x Reducer @ F5.3

Mount: EQ6 with EQMOD

Guiding: Orion ST80 with QHY5

Capture Software: CCD Commander, Maxim DL

Processing Software: Deep Sky Stacker, PixInsight

Exposures: 9 x 10 mins (Hα), 6 x 10 mins (OIII), 9 x 10 mins (SII)

Calibration: 25 x Bias, Flats, Darks

[alpal]

I don't mind the green colour - it looks great.

It's also nice & sharp.

[Zul]

Green color looks awesome!

[Gina]

WOW!!! I think that looks really great! Wonderful If I can get images like that when I get going with NB I shall be chuffed indeed!

[Tim]

Ah that's lovely Euan!

I know there is a trend towards blue/gold with no green, but the Hubble team certainly don't process that way, and I have noticed that you lose some definition and detail between various parts of the nebula when swapping the green out too much.

As for the purple stars, try using the Selective Colour tool and click on the Magenta tab, you'll be able to tame them in seconds

Tim

[Euan]

Thanks everyone, I should have said what the colours are:

Ha = Green

OIII = Blue

SII = Red

I know there is a trend towards blue/gold with no green

I don't have clue how to process NB to be honest. How do you get more of a yellow / gold effect? I had to drastically stretch the OIII and SII to get it to look right but the Ha hasn't really been altered that much, which is maybe why it's so green.

EDIT: Just found a guide which is what I could try next Creating Hubble Palette Color Mapped Images

As for the purple stars, try using the Selective Colour tool and click on the Magenta tab, you'll be able to tame them in seconds

I don't have Photoshop unfortunately, but the wife is thinking about getting into digital art and I can get the student version so I considering it for thing like this

[Euan]

I've downloaded CS5, it seems PS really comes into it's own with narrowband processing, I just couldn't find a way to do it in PI

This has brought out a bit more noise, but hopefully another hour on each of the OIII and SII will sort that

EDIT: pulled it just now while I try PI, thanks for the tip John

[johnrt]

Give the SNCR tool a try in PI - set to green & preserve lum tab checked.

Fantastic image by the way.

I've downloaded CS5, it seems PS really comes into it's own with narrowband processing, I just couldn't find a way to do it in PI

This has brought out a bit more noise, but hopefully another hour on each of the OIII and SII will sort that

[Euan]

Even using SCNR I couldn't get a decent result in PI, went back to PS for a re-process

[martin_h]

Thats looking very smooth indeed. I get a purple background to mine as well, will have to look into that for the future... http://stargazerslounge.com/imaging-deep-sky/171260-rosette-nebula-narrowband.html

[vdb]

Purple background is because not all colors start from the same blackpoint ...

Should be easily fixed in PS