Hi all - first post, so apologies if in the wrong place. I’ve just downloaded SIRIL and successfully stacked L R G and B images (separately) using the script which extracts background. The results look great, and really fast too. Very impressed.
But I cant see how to register those 4 images. I cant use the composite tool because it only has 1 star align, and I have some rotation, so looks like I need to do manual registration. But I simply dont understand how to do this. The current tutorials are all for the previous version. Can someone advise please… in real simple terms? The first big problem is I cant see how to load my 4 images (LRG and B)
Well… having stared at this for ages and got nowhere, I suddenly made some progress. Looks like you have to start with “conversion”… even though I dont actually need to convert as they are FITS files to start with … but thats where the load option is… YES?
But now I have a new problem. Registration failed on my RGB (LUM as reference) Would this be because the RGB are binned. Can they not be rescaled?
Welcome!
As you have found, it is not currently a documented process, and not a supported native function. You have to create a fake sequence by renaming the 4 result images, either manually or using the conversion indeed.
The registration failure may be because of a problem we identified in the 1.0 release: stars are not detected by registration and other tools if they are saturated, and in general at this step they are. If you already have done a linear match with the color channels, it’s even more the case. I’d recommend registering before the linear match and if this is not enough, normalizing images at the end of stacking or another trick to reduce saturation of stars.
In a future version we will fix that and enable global registration in the RGB composition tool hopefully.
OK - thanks for that. It’s a really great product for mono, but just a pity it cant cope easily with LRGB.
I found a workaround, but a bit clunky. Align the binned RGB and apply 2x drizzle. That scales it the same as the LUM. Then align the rescaled RGB s with the LUM.
registration is supposed to support images of different sizez, the RGB compositing tool too but with the limitation of the registration in it that is not possible with rotation… So I don’t know why it worked by upscaling, still it’s nice that you found a solution.