My workflow is very straight forward. Because of time constants I have to shoot jpeg. I just take it into photoshop 2024, adjust exposure and sometimes shadows if needed, sometimes a little tweek in the sharpness and that's it. I have 15 mins max after each race to select an image, add titles, print a3 and then mount and frame. After that pick two more images, resize all of them. then send them out via ftp and what's app.
Simply you’re running up against physics, at ISO 640 you’ve only got 8 stops of dynamic range to work with on those M43 sensors to capture a 16 stop scene. This looks like there’s not enough data being collected on the red spectrum because it’s a cloudy blue day and it’s being stretched and blocking up.
Really you need a faster lens, find a closer position where you can use an 85mm 1.4 equivalent (2 stops), and a full frame sensor (another 2 stops) to collect more colour data in the camera up so you have more dynamic range to work with. Remember if you can get 4 stops, that 16 times the amount of colour information. Then the tone curves on the colour channels will be smoother and not block up.