HaRGB Soul with Star 71 and 100D

[StargeezerTim]

This image is about eight and a half ours of integration time.m 6 hours luminence captured in 10 minute subs and two and half hours RGB captured last night in 5 min subs, both iso 1600.

I'm satisfied with the image but disappointed in the excessive noise, particularly in the space background. The data was captured over 3 nights with high cloud and not good seeing on any of the nights, which could explain the noise. My second go at combining Ha and RGB...

[gorann]

I like it a lot with nice details in the nebula,  but I am a little confused about your exposures/filters. First you mention Lum and RGB, but end by saying that it is your second go on HaRGB. In any case, did you use the 100D for everything (I assume it is mono modded) or did you use the 550D for RGB?

[StargeezerTim]

26 minutes ago, gorann said:

I like it a lot with nice details in the nebula,  but I am a little confused about your exposures/filters. First you mention Lum and RGB, but end by saying that it is your second go on HaRGB. In any case, did you use the 100D for everything (I assume it is mono modded) or did you use the 550D for RGB?

I used the 100d with 12nm Ha filter for the 6 hours Ha, used as luminence. I used the same camera with UHC filter for the RGB data. The 100D is modded. Hope that helps! 

 

[gorann]

Aha, you used the Ha for Lum. According to some (like Olly @ollypenrice) that is a no no, but I have done it myself a few times. I guess it may be rather ok for an object like this where most of the signal is Ha anyhow. Did you add some Ha to the red channel also. If not it could be worth a try.

[Rodd]

I like the palette.  Though adding Ha as lum does pinkify the image.  But, there must be a way of getting the incredible structure afforded by Ha into a luminance channel of an image without imparting anyb color change..  Ha would make the best luminance if this can be figured out.

Rodd

[simmo39]

V nice Tim.

[Allinthehead]

That's a very nice image Tim. As per Gorann's suggestion this is the method i use which seems to work well. http://bf-astro.com/tutorial/addHa.htm

[StargeezerTim]

1 hour ago, gorann said:

Aha, you used the Ha for Lum. According to some (like Olly @ollypenrice) that is a no no, but I have done it myself a few times. I guess it may be rather ok for an object like this where most of the signal is Ha anyhow. Did you add some Ha to the red channel also. If not it could be worth a try.

I used this method, method 2.

https://starizona.com/acb/ccd/software/ps_hargb.aspx

I've only just acquired a Ha filter so its all new to me!

[StargeezerTim]

3 hours ago, Rodd said:

I like the palette.  Though adding Ha as lum does pinkify the image.  But, there must be a way of getting the incredible structure afforded by Ha into a luminance channel of an image without imparting anyb color change..  Ha would make the best luminance if this can be figured out.

Rodd

I'm very inexperienced but would agree with you. From what I can see, using Ha as luminence gives the image much more depth and structure than the other blending modes. You would think it would be easy to change pink to red in PS but I can't seem to get a solution just yet!

[Rodd]

1 minute ago, StargeezerTim said:

I'm very inexperienced but would agree with you. From what I can see, using Ha as luminence gives the image much more depth and structure than the other blending modes. You would think it would be easy to change pink to red in PS but I can't seem to get a solution just yet!

I use PI--and I think it even more difficult with that platform.  But I don't really know.  I know when I add Ha as a luminance in my narrow band images it really works well.

Rodd

[gorann]

If you add Ha as Lum without adding Ha to the red channel, it will light up areas where there is not much red, which will then turn pinkish. So if you use Ha as Lum then you should first also blend some Ha into the red channel so it can light up its own signal.

Another problem with using Ha as Lum is that it will mess up the stars. Stars are quite small in Ha images and I can see in your image that you lost star colour since your Ha-Lum has only lit up the centre of the stars (zooming in I can see some faint colour around the stars). You may have to use layer masks to only add the Ha-Lum to central details in the nebula.

[Adam J]

Huum the h-a only looked very good, not sure but something seems to have added noise in blending with the RGB. You do need to add the Ha to the red channel of the RGB and then run a Gaussian blur on it prior to using adding the h-a lum layer if you are going to go down that route.

[StargeezerTim]

Thanks for you help with this one folks... I've learnt loads trying to get a good image from it but I think the main problem is the quality of the data, both Ha and RGB. It was all captured in poor to moderate visibility and the resultant noise makes it very difficult to get get a really good image. Visibility is forecast to be excellent tonight but it remains to be seen if the wind affects play or not. 

p.s. I did add Ha to the red channel. I think I've found a way of avoiding the overly pink rendition but the noise is still a nono...