Quote:
Originally Posted by Paul Haese
These are all lovely images. Each has its own aspects which make it lovely. I am happy to see that my colour rendering of Thors helmet is like yours so I must be close to having that right. Thanks for posting such fine images.
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Thanks Paul. Yes, I saw your Helmet post a while back. I think you were on the mark with colour balance. This is one of those targets that really thrives on singling out the wavelengths to get the details. The OIII is very pronounced and in most cases, richer than the Ha.
Quote:
Originally Posted by Ric
Hi Jase, I nearly missed these images. Boy am I glad I didn't. They are three fantastic images.
I'll have to say I was blown away by the widefield detail of Orion, the depth of the image in Thors Helmet and stunning ejecta coming from the Cigar galaxy.
Those three have made my day today.
Cheers
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Thanks Ric. I guess there's something in the three images for everyone!
Quote:
Originally Posted by glenc
Superb image of Orion Jase. The other two are also remarkable images.
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Cheers Glen. Pleased you liked them!
Quote:
Originally Posted by gregbradley
Hi Jase,
I wouldn't mind if you could explain your processing approach to mosaics.
For example do you do your LRGB combine and before you get into any Photoshop processing do you form the mosaic and then do your colour processing so it all gets changed at the same time?
Do you run something on the background first to help balance it out?
I remember someone posting somewhere it works if you run Gradient Xterminator on the panels first to help balance the backgrounds.
Greg.
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Well it goes something like this Greg (dramatically summarised as there is a lot of planning that goes into it).
Get a widefield image of the region that covers the mosaic field (monochrome or colour - doesn't make a difference). I typically download someone elses. Use registar to register the first mosaic panel to it. This will orientate the widefield image - which now becomes the "scaffolding" to build upon. You register all your other mosaic panels to it. You obviously don't use the widefield image in the final result - its simply there correct panel rotation or distortion which is quite an issue with mosaics. This is the technique Gendler uses. It works a treat. I only register the luminance panels to it to build the mosaic. Once all the luminance masters are aligned, you don't need the widefield image anymore. I balance the sky background and handle gradients manually in PS. No tricky automated tools, just the amazing features available in PS. You can use them, but I haven't had the need too. If you're not proficient in PS, then mosaics maybe a challenge. Once the luminance is built, make a backup copy that includes all the layers, then flatten it. I then use registar to align each of the RGB panels to the mosaic luminance, then pipe them into PS to start constructing the chrominance layer. With that done, it can be added to the luminance. If an RGB panel doesn't fit the scene i.e. different colours, I would suggest performing another RGB combine to correct it. Selective colour can work, but only on subtle differences. Finally, have patience and don't lose sight of the final goal as the mosaic process will certainly test you.
