[6S.Maraz]

The photoshop puzzles me. I just loaded map_T for stalingrad to check these RGB thing but I discovered something disturbing:
some grey namely lowland1 is displayed the same as lowland0 grey, you can't distinguish between them, it's just one color. Just opened side by side gimp and photoshop, cause I couldn't believe my eyes, the lowland1 grey simply vanished from photoshop. Maybe there are some settings to change?
Then also the rgb's for different greys were different from the rgbs given by gimp, but anyway gimp it's perfect in this sense, cause you have a very simple correspondence betweer rgbs and the lowland, midland ...

I jusy had the confirmation that Photoshop handles badly the grayscale values.
GIMP instead does handle grayscale well, apparently.

If you are accustomed at using Photoshop, just use the RGB mode, save a 24-bit TGaA and then convert it to 8 bit grayscale TGA using GIMP.
If you are just learning photoshop, it's better to revert to GIMP from the beginning.

Maraz