Adding Ha to DSLR RGB images

[Carole]

Following on from my previous thread of some time ago when I added Ha to the HH nebula.  Various comments were made and I've only just found time to take a look at these.

Fay kindly lent me a couple of her Ha images for me to practice combining with my DSLR RGB images and I think I am starting to get somewhere.

I tried Mac's set of instructions, but I don't think it works sucessfully with an already done RGB image (I may have to split the colour channels to get that to work), but I did manage to do part of what Chris suggested:

If you can get the colour balance where you want it in Photoshop with Ha as Red, then try applying the Ha again as luminance, you can then apply a Median filter to the RGB stack and you will see ther noise drop out, but remember to add a Saturation layer between RGB and Ha and set the saturation at 25% or more, or you will not see many colours.

This will then be an RGBHa  

I managed applying Ha as luminance, but would like a bit of help with the remainder.  Do I apply the median filter in the stacking process, in which case this is what i normally do anyway, or is there somewhere else I should be doing this?

No idea how to add a saturation layer (or even what it is) so would be grateful for some simple explanation on this.

Many thanks.

Carole

[Carole]

This is the experiments I did using Fay's Ha image and my DSLR image, Fay has kindly given me permission to post.  I don't think I've quite got the colour right, so any advice on that would be appreciated, but generally the experiment worked, although the combi image seems to be more noisy than the two individual images for some reason. 

Fay's ha image:


My DSLR image, rotated to match Fay's mono one:


Both images combined.  I have not cropped out the overlapped images as this is just an experiment:

[Fay]

any image, that I have done, adding colour,  always seem to have more noise & the subject is never as sharp, as well

[Carole]

That's odd Fay, I wonder why that is.

Carole

[Fay]

not doing it correctly, i should think

[Carole]

I have now had a "go" at colour processing using Mac's method, by taking apart the coloured channels in the DSLR image and saving them as individual mono channels.

It worked up until the adding the chain link and then I got stuck because the chain link was greyed out and would not link up.  Must have done something wrong, but will try again another day.

I also tried re-combining the separate channels using just paste into the individual channels and this worked fine.  This is all a new ball game for me, but I am getting there slowly.  Good practice for when I will need this at a later date. 

Will persevere, but any thoughts on the chain link would be helpful.

Carole

[Mac]

Just check that when you have copied over the mono images that they dont have a padlock on,
sometimes photoshop locks the layer, hence the  padlock.
if it does, then just make a copy and delete the padlocked one.

Mac.

[Carole]

No padlock Mac.  I'll give it another "go" and see what happens this time.

Carole

[Tony G]

This is the experiments I did using Fay's Ha image and my DSLR image, Fay has kindly given me permission to post.

Are you sure Fay is right person to be asking for the right to post the image and not NASA.
Did you process the last image?

Tony G

[Carole]

Not a lot of processing to do Tony, and both originals were already processed.

OK Mac.  I finally managed to put a chain link on the blue layer, by highlighting both the mask and the blue layer.

Now I'm stuck again as "create a clipping Mask from linked" only says "create a clipping Mask", so sounds suspiciously as though although I have a chain link on both the mask and blue they might still not be linked.#

I've gone right through the process now Mac and apart from the Create clipping mask problem I did everything you said, but ended up with a blue image (this was the top one in the layers).  

Carole

[Mac]

have you changed the layer type from Normal to screen,
if its Normal, then that layer is not see through and you will only
get that layers colour, hence the blue colour,
once you change it to screen it then becomes see through,
also just check the other layers are also screen.

Mac.

[Carole]

Yes did that Mac, followed everything you said.  Just wondering whether my version of PS CS3 might not do this, what version do you use Mac?

I will give it one more "go" though just to double double check.

Carole

[Carole]

Have done the process again and taken a lot of screen shots.

This is the three colours in layers


The blue layer being coloured


Blue layer linked to Mask thingy


Jumping further on, the green layer trying to create the the clipping mask to linked but it doesn;t mention linked even though I have linked them.



By the way, I have changed each one to Screen, but when I try to link them I can only do it if I highlight both the mask and the layer, and then the masked one shows Normal (not screen).  

this is the last (red) layer and the whole thing still looks blue.  Plus when I went to adjust the hue sliders at the end CS3 crashed, so never got a result from that.  

[Mac]

i use CS2 so yours will defiantly work.

when you click on any single layer or mask, if it is linked to anything else then
you will see the links in all the linked layers,

looking at your images the blue appears to be inked, but its shown as a normal layer and not screen
the red looks like its set for screen, but dosent appear to be linked.

the easy way is
Import layer,
change to screen
add hue/saturation adjustment layer
select BOTH layers and link
select mask layer and create clipping mask

repeat for the other layers,

if any one layer is not set to screen then that will completely destroy the image.

Mac.

Might have to run through this at a members evening.

[Carole]

Mac I did set them to screen but as I said I couldn't link them to the mask without highlighting both the layer and the mask it was linked to (The link is on the right side on my PC/PS you need to scroll accross to see it.  the layer is changed to screen but as soon as I clicked on the mask (to link them), the mask layer says normal and can't be changed though the layer still says screen.

Carole