Hi James, when doing your conversions try channel mixer after you grayscale. Click the monochrome box and try 60% red, 30% green, 10% blue then fine tune with curves for contrast you can vary the percentages of course but they should add up to 100%. You may still need to do a bit of burning in here and there. This process seems to get a better tonal range. You can also check out the digital monochrome tutorial on the forum.
Roger.
Eos 6D Mk1, 300D & G7x modified for Infrared, 17-40f4L, 70-200f4L, 100-400 f5.6 ISL, 15mm f2.8, 50mm f1.4, various Lensbaby lenses, a few tripods, flash, GoPro 7 black.