On my NVIDIA GeForce 7300 GT I can't set the black point to 0 (native). Dispcal seems ignore the -k0 -A1 -f0 settings and it correct always the three gamma curve of the LUT. http://lh5.ggpht.com/_Ogy3SF4bQ9Q/TGQ9niAuPKI/AAAAAAAAAIk/jzWMEBz18P4/s144/1.png Is it a bug? Thank you Marco