How to make a selection on a 16bit grayscale of only the darkest pixelspixels

[Ofnuts]

(04-19-2024, 02:38 PM)andyseabrook Wrote: The rest should not turn white but stay on whatever their current gray shade is.

Which the whole purpose of the "Darken only" mode set to the thresholded layer. The black pixels are darker than those of the original image so the composite image uses the black pixels, the white pixels are lighter than those of the original image so the composite image uses these original pixels.