Mosaic processing

[Peno67]

A couple of weeks ago I gave my first go at a 6 panel mosaic of IC 2118 from my AT115 and ZWO533 using Aaiair platform. Looking for input for best way to process. I have always used DSS. Tried one of the other paid options on a free trial and didn’t see the benefits of the cost. Doing some reading, on my first go I stacked each panel separately using flats, darks, biased. I then opened each in ST and cropped, binned, wipe then set each frame at the same dev percentage. From there joined in ice then reopened in ST. Came out ok but this process didn’t allow for proper color definition due to being Linear? Wondering if I would be better off processing each frame fully in ST using the exact same settings then stitching in Ice or if there are other suggestions. Attached end result. Not a lot of data time as I wanted to make sure it worked first. Each frame had about 30 minutes of light data.

IMG_0140 Large.jpeg (436.46 KiB) Viewed 9975 times

[Mike in Rancho]

I am no mosaic expert, having only done a couple. They seem inherently difficult, trying to get so many things to match across the panels from gradients, to color balance, to the non-linear stretching. True even if stitching linear rather than all post-processed. But, so many different ways to go about mosaic creation.

Hopefully some more skilled mosaic makers will chime in!

However, I surmise that the lack of color may come from saving out the panels while in a tracking mode. Assuming a 533MC, did you open each panel and then go through your listed steps of crop, bin, wipe, and (I'm guessing) FilmDev, and then save?

If so, I think you probably only saved the synthetic luminance. A few ways to perhaps remedy that. One would be to save out after using Color (which is getting pretty close to fully processing each panel separately). Another would be to use Compose, loading your OSC file into each of the R, G, and B slots, and choosing legacy RGB, RGB. Finally, you might be able to still use Open but choose non-linear (even though it is linear), but it's been a long time since I did anything like that so I could be wrong.

Experiment! Just whichever you do you don't want to save out while in tracking/compose mode (button lit up green) prior to the Color module, as your TIFF save at that point will be grayscale (despite technically being an RGB TIFF).

Let us know if anything like that works and you get your color back!

[Stefan B]

I haven't done a lot of mosaics either, but I already encountered the problem with the monochrome outcome when processing a M31 mosaic (viewtopic.php?f=11&t=2329). The reason was that I opened via the 'open' option with the data source being OSC. This results in a monochrome image and you only get the colors back in the color module. If you choose the 'linear' option without specifying the data source you should be fine.

Regards
Stefan

[LuckyEddie]

I've just processed a 6-panel mosaic of the moon.
My post-stacking workflow was to use StarTools for FilmDev, Sharpen, SVD and Colour before exporting and stitching with Hugin. Once stitched I found the file too large to work with in StarTools at all - it just gets killed by the OOM. I ended up with minor tweaks (saturation and NR) in GIMP.

[Peno67]

Thanks for the input. I will play around a bit. I did save before turning tracking off. Interesting ideas.