Add H-Alpha Data to RGB image

[astro mick]

Hi could anyone tell me in lay terms the best way to add H-Alpha Data to my RGB image.

I am having little success with this and always end up with a bright salmon coloured image.

I have access to Photo shop,but with limited knowledge,its proving a night mare.

Hope someone can help.

Mick.

[steppenwolf]

The key to this is to blend your Ha data into your red channel and then use this Ha/Red channel for your red channel or even for both L & R channels. You could try it in a single blend or better still by multiple iterations.

[astro mick]

Steve.

Thanks for that,the only question is how?

How do i blend both channels.

As i said limited knowledge of photo-shop.

Mick.

[steppenwolf]

Open the RGB colour image, select ‘channels’ tab, click on the red channel and type Ctrl ‘A’ followed by Ctrl ’C’. This will copy the red channel to the Clipboard. Select File - New to form a new document and name it ‘Ha_red’. Type Ctrl ‘V’ to paste the red channel into the new document. Now select the Ha image and type Ctrl. ‘A’ followed by Ctrl. ‘C’. Next select the red channel only image again and type Ctrl ‘V’ to paste the Ha channel on top of the red data.

Select ‘Layers’ tab and use a 50% opacity setting and align the two layers until the stars line up exactly. Now adjust the opacity of the Ha layer until you get the most pleasing mix of the two images. Select Layer - Flatten Layer to flatten the layer. Type Ctrl. ‘A’ followed by Ctrl. ‘C’ then select the original RGB image and type Ctrl ‘V’ to past the blended red data into the original red channel. You will now have a more detailed Ha+R/G/B image.

[MartinB]

I do something similar but prefer to keep the Ha as a seperate red layer and blend it into the RGB. It gives a bit more flexibility.

Are you using a one shot colour camera or are you trying to create an Ha enhanced LRGB? The salmon colour normally comes from an over dominant luminence.

[astro mick]

Thanks for that detailed answer Steve.I will give it ago,and see what i get.I did,nt realised things were so complicted.

High Martin,No i am using a mono camera,and taking an hour,s worth of H-Alpha,and 20 mins each of RGB.I am not taking a luminance.

Should i ?

Mick.

[Whippy]

So would you be using the Ha as a luminence layer or adding it into the Red channel?

Tony..

[MartinB]

What target are you working on Mick?

[astro mick]

Tony.

I was using the H-Alpha as a luminance layer.I would make the RGB image active,and open the H-Alpha image.I would convert the H-Alpha to both 8 bits and change it from greyscale to RGB.i would then make the RGB image active.Then i would copy the RGB image to the clipboard,and paste onto the H-Alpha image,creating a washed out colour image.

Finally i would change the blend mode to colour,and this is where i get the bright pink salmon coloured image.

Hope this helps.

Martin.

I am working on part of the veil neb,but regardless of which emmission neb i work on i always get this pink result.

My ordinary LRGB images are ok,but i want to get more detail by using the H-Alpha filter.

Mick.

[Whippy]

In that case Mick, all you do is treat the Ha in the same way as you would with a normal mono luminence image. I still use Martin's LRGB primer to put it all together: http://stargazerslounge.com/imaging-tips-tricks-techniques/57834-lrgb-imaging-primer.html .

If you're also using the Ha data to increase the Red, I asked the same question. There's a few links to methods in the thread: http://stargazerslounge.com/imaging-discussion/135054-adding-ha-data-lrgb-image.html .

Tony..

[martin_h]

Here's a primer to have a look at - Starizona's Guide to CCD Imaging

[astro mick]

Thanks to everyone,for your wonderful input,i will try and put it all to good use.

I do need to brush up my skills in Photoshop though.

Cheers.

Mick.

[ollypenrice]

I'd avoid using Ha as luminance beyond about 15% opacity. Try that right at the end.

I use Steve's approach but I set the blend mode to Lighten, not Normal. This has a less deleterious effect on star colour. Build up in iterations and with each iteration red may start to ge out of hand so you can drop it a little in Curves. It can help to have a copy of the Pre-Ha image open so you can try to keep the colour looking similar as you pile in the Ha.

At the end it can be worthwhile to re-apply the orignial star colour from the pre Ha image. This can be a fiddle but if you use either Martin's Star Layer tutorial or Noels Actions to select just the stars it can be cajoled into working. It is all down to select-expand-feather-opacity when it comes to making it look natural.

Olly

[Gerry Casa Christiana]

On 31/05/2011 at 14:52, steppenwolf said:

Open the RGB colour image, select ‘channels’ tab, click on the red channel and type Ctrl ‘A’ followed by Ctrl ’C’. This will copy the red channel to the Clipboard. Select File - New to form a new document and name it ‘Ha_red’. Type Ctrl ‘V’ to paste the red channel into the new document. Now select the Ha image and type Ctrl. ‘A’ followed by Ctrl. ‘C’. Next select the red channel only image again and type Ctrl ‘V’ to paste the Ha channel on top of the red data.

Select ‘Layers’ tab and use a 50% opacity setting and align the two layers until the stars line up exactly. Now adjust the opacity of the Ha layer until you get the most pleasing mix of the two images. Select Layer - Flatten Layer to flatten the layer. Type Ctrl. ‘A’ followed by Ctrl. ‘C’ then select the original RGB image and type Ctrl ‘V’ to past the blended red data into the original red channel. You will now have a more detailed Ha+R/G/B image.

Hello

Can I ask a question my stars don't quite line up. How do I turn the photo clockwise in small steps. I see rotate etc. I'm also struggling putting together my H Alpha with rgb. I'm using Cs2 photoshop 

Thanks 

[steppenwolf]

5 hours ago, Gerry Casa Christiana said:

Hello

Can I ask a question my stars don't quite line up. How do I turn the photo clockwise in small steps. I see rotate etc. I'm also struggling putting together my H Alpha with rgb. I'm using Cs2 photoshop 

Thanks 

Usually, the separate images will have been aligned previously using your alignment/stacking software and this is the quickest and most accurate method to use. Depending on what software you have available, you can still do this later on in the processing by flattening your two images, saving them as 16 bit TIF files and loading them into suitable software like MaxIm DL, AstroArt, PixInsight or even better, Registar to align them and then re-import them back into PS2. You *could* try rotating and sliding a 50% opacity Ha layer on top of the Red from within PS2 by using Edit - Transform - Rotate starting the rotation by grabbing one corner of the image, moving it a little and then using the up and down keys to control but this can be very laborious!

Try and align them outside of PS2

[Gerry Casa Christiana]

1 hour ago, steppenwolf said:

Usually, the separate images will have been aligned previously using your alignment/stacking software and this is the quickest and most accurate method to use. Depending on what software you have available, you can still do this later on in the processing by flattening your two images, saving them as 16 bit TIF files and loading them into suitable software like MaxIm DL, AstroArt, PixInsight or even better, Registar to align them and then re-import them back into PS2. You *could* try rotating and sliding a 50% opacity Ha layer on top of the Red from within PS2 by using Edit - Transform - Rotate starting the rotation by grabbing one corner of the image, moving it a little and then using the up and down keys to control but this can be very laborious!

Try and align them outside of PS2

Ah yes I'll have to try one of the programs  you suggested because DSS won't do it at all. Rgb frames and H Alpha together  

[geordie85]

3 hours ago, Gerry Casa Christiana said:

Ah yes I'll have to try one of the programs  you suggested because DSS won't do it at all. Rgb frames and H Alpha together  

If you use the same reference frame for both then they'll be aligned. Just remember to un-tick the check box of your reference frame on your other set of images.

[Gerry Casa Christiana]

14 hours ago, geordie85 said:

If you use the same reference frame for both then they'll be aligned. Just remember to un-tick the check box of your reference frame on your other set of images.

I'll give it a try. Thanks. When you say reference frame you mean under group1 instead of main group i untick the first frame there? 

When I try and stack my rgb frames under main group and h Alpha under the second group it only stacks the rgb and doesn't use the h Alpha data. 

Thanks

[geordie85]

43 minutes ago, Gerry Casa Christiana said:

I'll give it a try. Thanks. When you say reference frame you mean under group1 instead of main group i untick the first frame there? 

When I try and stack my rgb frames under main group and h Alpha under the second group it only stacks the rgb and doesn't use the h Alpha data. 

Thanks

What I do is open my one set of data files in the main tab, register but don't stack. Right click on the image with the highest score and click use as reference frame. Then stack.

Once they're stacked, I remove all the fames except the reference frame. Open my next set of data files in the main tab again. Click check all but untick the reference frame, then stack.

This way all my data sets are aligned to 1 frame and should match up when it comes to combining them in Photoshop. 

I hope I've explained this clearly enough for you. Any more questions, just ask.

[Gerry Casa Christiana]

Awesome makes perfect sense! But for the second time you leave it unchecked but still as the reference frame. 

So with mine I have 28 rgb frames. Register and stack using the highest score as the reference frame. Once done remove all frames except the reference frame then add H Alpha frames but use the reference frame as the reference frame but don't actually stack it with the H Alpha. Am I thinking correctly? 

[geordie85]

2 hours ago, Gerry Casa Christiana said:

Awesome makes perfect sense! But for the second time you leave it unchecked but still as the reference frame. 

So with mine I have 28 rgb frames. Register and stack using the highest score as the reference frame. Once done remove all frames except the reference frame then add H Alpha frames but use the reference frame as the reference frame but don't actually stack it with the H Alpha. Am I thinking correctly? 

That's correct 

[Gerry Casa Christiana]

Thanks. Ok I've tried it. Still does not align but I did manage to do it with Registar. 

I'll keep in mind what you said though. 

Thanks for taking the time

Merry Xmas to all your family 

Gerry