colouring my ring

[Kaptain Klevtsov]

After my go at M57 worked out well on the EQ6, I got to wondering about colouring it in a bit. This guy http://www.narrowbandimaging.com/ does some great stuff so I thought I'd have a bash myself.

Anybody got any tips regarding ratios of sub-exposures etc?

First go will probably be M57 adding Ha and OIII to the mix and giving them colours then use the sharpened up ring (in deep sky section, second image in the thread) as luminance channel. Before I waste a lot of time is there anything obviously wrong with the plan?

I intend to give each narrow band image the same total time but split so that the sub-exposure times might be different. Should I bin 2X2 the colour frames or what? If I bin them is it simply a matter of doubling the size in Photoshop to line up with the luminance channel, or do I shrink the luminance to half size?

TIA

Captain Chaos

[MartinB]

Go for it CC! I don't think you can bin with a web cam though can you? It's not really necessary on a your web cam though since you can just increase the gain.

As a rough rule I find that an Ha needs about an extra 30% exposure but in practice I have always given it as much as my set up would allow then adjust the gain to give enough info.

You will then have a problem of having red, blue/green and luminence rather than RGB. Your best bet is to Lassoo the Ha and OIII and layer them with the lum. Then adjust the levels and the colour channels ( I think it is better to adjust levels and curves after combining rather than before). You will then hopefully have a good ring but a dodgy sky. So flatten the image, lassoo the ring again and paste it into the original luminence layer using 100% opacity. You then have a coloured ring and a black sky with white stars.

An alternative way is to make a blue and a green layer using the OIII, in fact this may be better.

Don't know whether you have used layers in PS. You will probably have some rotation in your images unless you are using a filter wheel. I have spent hours teaching myself how to do this. PM me if you need any help.

[Ambermile]

Desire will bin a webcam. I also think Vega will as well.

Arthur