Problem with bump mapping

[OnoSendai]

I did my changing to greyscale in GIMP. No idea what photoshop is doing, probably failing hard.

[OnoSendai]

you can see in you test that using gamma 1 is needed to have the displaced middle part centered, with gamma 2.2 it hangs way to low...

Yes, only with gamma of 1 will pixel values of 128 map to a middle value of displacement. The question is whether the author/program that created the displacement map intended pixel values to map to 128 or not.

[Zom-B]

Played around with my PS colorsettings.
Seems that the problem was related to bad settings here -.-'

[galinette]

Just some info, I did scratch my head for some time with photoshop by the past understanding when it uses gamma, and when it does not.

Photoshop works in linear colorspace (gamma=1) in 32bit/channel mode, which may give totally different results than in 8bit or 16bit modes (gamma depending on working colorspace, which means 2.2 for sRGB)

For instance, if you do a gradient from 0 to 255, this will look totally different in 32bit mode and in 8bit mode.