M33 Galaxy

[Carole]

This is my last one from July DSC (thank goodness you all say!) 

Dual Rig:
Mount: HEQ5
WOZS71/Atik314L + FR x 0.8 : 13 x 600 + 4 x 900 Luminance
SWED80/Atik460EX + FR x 0.8 : RGB:
Blue & Green 5 x 150 secs + 4 x 200 secs binned x 2
Red: 5 x 150 secs + 7 x 200secs Binned x 2
Ha 5 x 10min

Does any-one know a good tutorial on how to add Ha to get red high lights in Photoshop?
Have tried all sorts of ways, including adding to the red channel? Thanks.

Total Luminance 3h 10m
Total RGB 1h 27.5m
Total Ha 50m

Grand total = 5 hours 27minutes
Taken over 2 nights



With Ha highlights added (finally)

[MarkS]

A very nice result!  It's not easy to get those outer faint arms.

M33 is one of my favourite galaxies and is on my list for later in the Summer with my C11 and Sony A7S combo.

Sorry, I don't know the best way of combining H-alpha and the red channel.

Mark

[Carole]

Thanks Mark.  I have been scouring the internet for the Ha addition and I see I posted a question on Astrobin about this issue some time ago and got a few replies, but none of them come up with any better solutions than what i am already doing and that is to combine the Ha into the Red channel.

I found I got a better result (3rd try yesterday) by combining the Ha to the red channel and blending it about 60% and blend lighten, but still I am not getting the results that I see on some forum posts.  The next time I see a good result I am going to contact the poster and ask how they did it.

I also tried in the past putting the coloured image over the Ha image (changing the mono Ha to RGB) and blending the two in one of the blend modes and increasing the Ha in the red channel, but that didn't work this time.   So am currently stumped and frustrated.

Carole

[Carole]

Had one more try almost replacing the Red channel with Ha.  But then this destroyed the star colours, so then pasted the original image over the top and blended as lighten.

Must write my own tutorial on this before I forget what I did.

Have added the image into the first post for comparison.

Carole