Halpha help needed

[assouptro]

Ok... I have a question.

I have the basics sussed, using dss and ps3 on my modded eos350d images.

I have recently bought an astronomic Halpha clip filter and have taken some images that I am impressed with.

Now I would like to combine the Halpha images with the "normal" ones.

should I just mix them up in dss and if so what's the best way, is there any boxes that need checking?

Or is it better to stack them individually then combine them in something like photoshop? If so how??

Please would some kind individual help me out.

Thanks

Bryan.

[blinky]

I would stack them individually then mess about with it in photoshop. The first thing to do would be to add the Ha as a Lum layer. Others will be along in a min that will no doubt give some more info on doing this as it's not something I have personally done.

I quite fancy an Ha filter for my DSLR so will be interested to see your results.

[MartinB]

Hi Bryan, I can't give you any advice on DSS, but I have played around quite a lot mixing Ha into colour images. I always use photoshop. One method is to split the colours into channels and add the Ha to the red channel using lighten as the blend mode. You can do this before stretching but trial and error is needed to get the strengths of the red and the ha balanced. The red will be good for star data and non Ha emission areas. An alternative is to blend processed Ha into your processed colour image. You need to convert the Ha to red. Noel Carboni's action is good for this, the one that doesn't colour the dark areas. I believe it adds a small amount of blue to produce an accurate Ha hue. Alternatively you can do it yourself in PS.

Normally "lighten" is the best blend mode to use. You will need to play around with curves and levels in the Ha layer to get the balance right but you can play around with screen or even "normal" with a star layer on top to protect the star colour.

I've never found a simple work flow that works for every situation

The aim is to try to preserve the deep red Ha hue whilst retaining the Ha resolution. This always seems a bit of a compromise. The thing to avoid is turning the Ha into a salmony orange