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kosborn
10-07-2019, 10:43 PM
Hi all,

There have been a couple of great examples of the Dark Tower Nebula in Scorpius (Cometary Globule GN 16.43.7.01) recently which inspired me to have a go myself. This is very much a work in progress but with the clouds as they are I am too impatient and had to check out the data before they were complete. Much more Ha and probably a bit more LRGB to go and certainly colour balance is out but here it is so far... No high res versions until complete!

North is to the right(ish). The framing was chosen to include the extension of Ha to the south (left) and to satisfy the rule of thirds. :P

Kevin

Placidus
11-07-2019, 07:13 AM
Great framing. Three lovely bright and colourful stars to the left. The stream of faint H-alpha heading left is the real target. Well shown.

Does anyone know whether the stream of H-alpha is being blown off the dark tower by that bright star, or whether the head of the tower is actually far behind and uninvolved?

kosborn
11-07-2019, 08:01 AM
I'm not sure but I think the Ha stream is just part of the background ionised hydrogen where the Dark Tower is formed from a molecular cloud. The Ha image sort of suggests that.

Even though this is an interim image from incomplete data, I'm disappointed with how I've processed it. The RGB and Ha images I quite like but I can't seem to get the Ha blend right. Any PixInsight experts with suggestions...?

Kevin

Bart
11-07-2019, 10:20 AM
There is not a lot of info on this object, and not really a lot of images either, so getting a feel for the field and image is difficult.

Probably the best way to add the Ha is to use the method Andy described in my post on the Dark Tower or try the NBRGB script in PI.

I toned down the Ha in my image as no matter what method I used, it came out orange or too red.

Looking good so far. :thumbsup:

strongmanmike
11-07-2019, 12:40 PM
Yeah I recon it looks ok too Kevin, nice a subtle. The straight Ha will often look more contrasty than the colour combine due to greater contrast in B&W

Mike

Ryderscope
11-07-2019, 10:27 PM
Well done with the framing and composition on this one Kevin. Makes for an engaging image :thumbsup:

Placidus
12-07-2019, 07:45 AM
The H-alpha only version is excellent. Can see what's going on now. As you say, clearly stuff evaporating off the tower.

Ross G
13-07-2019, 05:43 AM
A very good photo Kevin.
Great detail and I love the composition.


Ross.

Paul Haese
13-07-2019, 12:04 PM
Nice colour and detail Kevin.

kosborn
14-07-2019, 07:17 PM
Thanks all for the comments. I wonder whether the rgb and the Ha images should stand alone without any attempt to combine them... Or maybe I should just get better at processing.. :P

The ZWO Ha filter does make things difficult with the strong reflections around the brighter stars. Does anyone have any experience with the Astronomik 6nm Ha filter versus the 7nm ZWO Ha filter (I'm using the ZWO ASI1600mm camera)? I notice Bintel have the Astronomik filters available.

Kevin