I've spent hours searching for this idea both here and on the greater interweb without success, but if I'm duplicating something I've missed please point me to it. My other caveat is I'm totally new to trying any sort of sophisticated post-processing. To date the extent of my "lab" work has been adjusting contrast, exposure, color levels, etc., so please keep in mind that I probably won't understand technical discussions without some supporting explanation. My apologies and thanks.
So, to the crux of the matter. I want to combine in some way 3 separate photos of the same scene (I don't care RAW or JPEG at this point though I've been working in RAW) such that each photo contributes only one color channel (red, green or blue) to the final composite image. The end result being that if I shot three photos of a completely static scene, then the final composite image would be indistinguishable from any of the 3 original photos rendered in full color.
I've tried stacking them and then "turning off" 2 of the 3 channels on each photo, but I don't think I've actually "turned them off" in a contribution sense, I think I've just picked one of the channels to view by clicking the eyeball icon in the channels panel. I've read that I need to convert them to greyscale first, but I don't understand how removing all the color information from 3 individual photos and then stacking them could possibly result in a color image. When I try what I think is being described I just get a black result. I've also played with (without really understanding what I'm doing) trying to create a spare channel from just one color channel for a photo and then applying (again I think) a greyscale mask layer(?) to the photo using the spare channel. Then I just end up with a white image.
I know what I'm trying to achieve is possible, there was an article on one of the photo news/collaboration sites a couple of years ago describing this technique. But I failed to save it, can't find it now and just don't know enough about what I'm doing to be able to form the query in such a way as to get the internet to cough anything up.
Thank you for any pointers or tips anyone can provide. And thank you to Serif for creating such a wonderful alternative to Adobe which is really out of the price range of hobbyists such as myself. I've really enjoyed working with Affinity so far and am looking forward to learning how to use it in depth.