A Better Way to Combine LRGB That Gets Around PixInsight's Limitations

[@SKYST0RY]

NOTE: I made an error in the order of the early development sequence. It is actually better to execute the LinearFit process after Star Alignment.

[@IronMan-2024]

I have noticed you are speaking much faster these days. The first videos were more mesmerizing, almost hypnotic. You must be getting excited! Thanks for your wonderful videos.

[@SKYST0RY]

Sometimes when I record a video, i realize I left some crucial little bit out then have to go back and re-record a section a little faster to squeeze everything in without having to stretch the whole video. But, yeah, sometimes I probably get a little jazzed up about a topic.

[@shubinternet]

I’m sorry, I’m only five minutes in, and I’m already completely lost. It is not at all clear to me what the new part to the process is, versus what you were doing before. I do like being able to step back and see the whole process in one go. So, as far as that goes, I think you’re doing well here. But if you’re introducing just one new step, it seems to me like you’d want to highlight just that part that’s changed and how this new step is an improvement over the previous method. Thanks for all your hard work, and trying to explain this to us!

[@SKYST0RY]

Totally understandable. This is a simple-deep topic that results from running into more PixInsight limitations. I try to avoid being a negative channel and just titling the video: For god's sake, don't combine LRGB in PixInsight. But that's really what the issue is in this video, and I guess it would have been clearer to somehow point that out in the title and description. PixInsight's LRGB combination is very limited. ChannelCombination and LRGB Combination just apply a modified screen composite to the L and RGB, and they can be picky and buggy. If an image isn't processed in the way PI wants, the outcomes are poor to completely unusable. You have to push about 9 minutes into the video to get the full story. One can work around all this by combining LRGB in a nondestructive, layer-based photo editor where they have absolute control of how they composite, and the nondestructive, layer-based photo editors don't spit out garbage output if the image files aren't exactly to their liking. I was struggling to find a way to express this in the video without seeming hyper negative about PI. But, honestly, to me PI's only redeeming qualities are the Weighted Batch Preprocessor, the Subframe Selector and the convenient Star Alignment and Histogram Transformation tools. I think PI's staying power as a photo editor for AP is simply that it's been accepted as a standard and some persons are reluctant to move on. (You'd be amazed how many hate messages I get from radical PI users for my videos that encourage people to use other editors.) Frankly, if it weren't for RC Astro, I would have long since found a way to ditch PI. IMO, it's dated, backward and a poor way to process AP compared to modern editors.

[@SKYST0RY]

I've retitled the video and changed the description to try to make it clearer without being overly negative. Please let me know what you think.

[@AmatureAstronomer]

Interesting.

[@Rafastro]

Does the image blend script do any of the combination you were talking about? It mentions several kinds of blending, like lightness, saturation, screening, etc. …

[@SKYST0RY]

I tried the IB script a while back but it basically replicates functionality that has existed in layer-based editors for ages so I don't use it. But according to Block's post about it on the PixInsight Forum, it allows you to apply what is tantamount to blending (composite) methods to the layers. I still prefer to do this in AP where I can blend multiple layers at once according to my own parameters, and mix, match, merge and edit them according to my preferences. TBH, this video is only an introduction to the power of blending. We'll go deeper into blending in future videos.