Don't scale values that are already to scale, and fix estimation issue for unknown cameras.
Don't scale values that are already to scale, and fix estimation issue for unknown cameras.

anarsoul/rawspeed,klauspost/rawspeed,LebedevRI/rawspeed,klauspost/rawspeed,darktable-org/rawspeed,mgehre/rawspeed,LebedevRI/rawspeed,LebedevRI/rawspeed,LebedevRI/rawspeed,darktable-org/rawspeed,darktable-org/rawspeed,mgehre/rawspeed,darktable-org/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,anarsoul/rawspeed,anarsoul/rawspeed