Make your own RGB of my Rho/Antares shot

[erick (Eric)]

ps. and flip Garyh's vertically

[jase (Jason)]

This is generally a difficult area to process. Quite a vast dynamic range and colour complexity. The orange/yellow hues are difficult to obtain well. I'm not too certain the correct color balance on the Astrodon’s. They are not exactly a 1:1:1 ratio, but close. You still need to take into consideration the blue extinction factor as well.
I settled on a R:G:B of 1:1:0.8 for the final RGB combine.
As red and green make yellow, this emphasises the orange/yellow hues. I only used 20% saturation. Could have gone higher, but lacking sufficient data would result in more noise. I used the R channel with minor sharpening applied, this was then layered onto the RGB image with 80% opacity. RGB was Gaussian blurred (very mild). I've clipped in green and blue which I expected as I should have raised other colour levels instead. Getting rid of the green halo around Antares was a pain. I used the colour selection tool then dropped the green channel using curves - this needs more work in particular greater feathering.

This is a good example of what the area is suppose to look like with good colour balance and processing - http://www.starryscapes.com/nebula/rho_ophiuchus.html

[okiscopey (Mike)]

Composite .. latest edition!

[iceman (Mike)]

Beautiful result, Jase!

[Ingo]

Where does the red green and blue come from? I put them in photoshop, layed them on top of eachother, and there were no colors?

[montewilson (Monte)]

Have you converted the red to RGB from Gray scale before adding the other colours?

That is very important.

[avandonk]

I think that all need to be flipped as they are the mirror image. Here is one I did in late March.
Large version here 1.5MB
http://members.optusnet.com.au/~trlee8/rho_oph.jpg

Thread here
http://www.iceinspace.com.au/forum/s...ad.php?t=18680

You can see my version lacks the delicate detail in Monte's data due to different optics . But it shows more dynamic range.
I think if Monte tried series of exposures each time doubling the exposure time EasyHDR would then get all the dynamic range of this region. It is a difficult region to image.
I would be interested to have a go at a set of RGB's taken this way.

Bert

[RB (Andrew)]

This is a great idea for a thread Monte, thanks for the oppertunity to try our hand at RGB processing.
I had another go at it too.

Maybe you can upload the full res set of frames onto the IIS server (ask Mike).

Great capture and thanks again !

[okiscopey (Mike)]

Originally Posted by Ingo

Where does the red green and blue come from? I put them in photoshop, layed them on top of eachother, and there were no colors?

Ingo, the way I did it (which might be the long way round) is as follows:

Turn each of the JPEGs (which are 16-bit greyscale images) into RGB.

Note: I use Photoshop CS2 which handles 16-bit images, earlier versions handle these in varying ways … you may need to turn the originals into 8-bit greyscale and then into 8-bit RGB, thus losing a great deal of the tonal range.

For the blue one, add a new layer and fill it with solid blue R=000 G=000 B=255

Change the filled layer from ‘Normal’ to “Multiply’.

Flatten the image. You now have the ‘blue’ image.

Do a similar operation to the green and red images, using R=000 G=255 B=000 and R=255 G=000 B=000 respectively.

Copy and paste the green and red images onto the blue (background) image to give a three-layer file. (You can drag and drop between files, thus avoiding the clipboard, but then you may have alignment issues.)

Turn layer 1 (green) and layer 2 (red) from ‘Normal’ to ‘Difference’.

Voila … a vaguely-coloured image.

You can then muck about with the individual layers (saturation, etc.) to see what effect it has on the displayed image. I did this to at least make the ‘whites’ white. If you flatten the image, you can do the overall levels, saturation, etc.

Trouble is, it’s a lot of work to produce - at least in my case - a final image inferior to the astro processing s/ware used in the other posts (not to mention the knowledge and experience that goes into tweaking the red, green and blue images along the way).

I assume the result I obtained is more-or-less the best one can do using PhotoShop alone.

[Bassnut (Fred)]

Theres a much easier way as Monte infered.

In CS, convert the red image to RGB and simply copy and paste the green image into the green channel (as is, no RGB conversion) and the blue image into the blue channel. The red channel already has the red image from the 1st RGB conversion.

Now you can process each channel seperately or the RGB layer altogether, its already a "flat" single layer.

Fred

[Garyh]

Originally Posted by Bassnut

Theres a much easier way as Monte infered.

In CS, convert the red image to RGB and simply copy and paste the green image into the green channel (as is, no RGB conversion) and the blue image into the blue channel. The red channel already has the red image from the 1st RGB conversion.

Now you can process each channel seperately or the RGB layer altogether, its already a "flat" single layer.

Fred

Thats similar to what I did, made new RGB image then pasted into the appropiate channels. Done some gamma corrections on the various channels etc, then the usual on the whole lot..
Very interesting experiment!!!! To see them all together and what everyone has done different to them...........
Mine looks like its a bit on the blue side with color balance..
thanks Monte for the chance to have a fiddle...

[Doug]

Either way is just as good...it comes down to personal preference. IMNSHO.

[ving (David)]

what a brilliant idea!

funny how everyones is different!

[bloodhound31]

Great idea and awesome images peoples!

I have no idea how you do it, but I am impressed

Baz

[okiscopey (Mike)]

Originally Posted by Bassnut

Theres a much easier way as Monte infered.
In CS, convert the red image to RGB and simply copy and paste the green image into the green channel (as is, no RGB conversion) and the blue image into the blue channel. The red channel already has the red image from the 1st RGB conversion ...

I used to learn something new every day, now thanks to IIS I learn at least three new things every day!

I use PhotoShop a lot for general photographic work, but never knew you could copy/paste into one channel. I note the channel has to be selected for this to work (of course!), and if you have two channels selected the copied image is pasted into both.

[Doug]

For the time being..............here is a tentative go.
Hope to have another go in a fortnight or so
Thanks Monte
Edit: the 1st image looks worse on the web than it did in PS2. second image is from before I became preocupied with getting Antaries to shine with its orange glory.

[montewilson (Monte)]

Guys - Thanx so much for all the replies. I am pleased to see there is such interest in putting together these images.

I, like a few others have commented am also surprised at how many variations there are. What is important to remember is that not one of them is wrong and also none are "correct". We can only speculate what it is really like.

I will have some more soon. I will see if I can put the full frame shots in tif on the FTP. They are not small files but I am sure they would provide plenty of entertainment.

The Astro Imaging Section of the ASNSW will be having it's Bi-monthly meeting on the 20th in Epping. Non members are welcomeand encouraged to come along too.

We will be taking some pictures with my TAK FSQ-106 and a digital SLR and processing them there on the night. Come along, bring a laptop if you have one and meet with other astro imagers in a relaxed event. If its cloudy we'll all sit around and shoot the breeze on AI matters. But seriously we will have plenty to do even if its cloudy.

Hope you can make it.