been thinking about colour.
not a lab tech, but I used to do B&W photography.
It is almost a standard that a B&W photographer uses a coloured filter, usually a yellow or orange filter to raise contrast a bit.
Even more so in the days of orthochromatic film.
so first I found these:
Aviation of Japan 日本の航空史: Notice of Update ~ RLM 02 & RLM 63 Graus
The Mölders image was straight converted to greyscale, but maybe I should have removed the yellow cast first?
then did a simple conversion to grayscale
Then selected each of the colours, increased the red channel +50 and the converted to grayscale.
so the background gray was untouched.
The same but now with the magenta channel
Again, but now with the yellow channel
And to finish of, I did it again, but now with the yellow +25 and the red +25
I have no idea if this is scientific or not, I probably should have used the colour profile of contemporary Agfa film to convert to grayscale.
I hope what I did makes sense, if not fire away!