10, 12, or 16 bit Color Palette Graphic Software search

[Flemming]

Hello
I have been searching for a pixel based graphic software package for Windows that can assign a 10, 12, or 16 bit (65,536) value to each RGB channel (48 bit color depth @16 bits).  Photoshop will work with a 16 bit per color file, but will only allow 8 bit color changes.  I need the higher resolution to create graphic targets that will be exposed onto film with an Arri Laser film recorder that has 16 bit per channel resolution for exposure.
Suggestions?
Thank you
H

[Panopeeper]

Hello
Photoshop will work with a 16 bit per color file, but will only allow 8 bit color changes

Excuse me, but what does this mean? PS does not work with 16bits, but it does work with 15, and that appears for me to be real. If I make changes in 16bit mode, then I can observe the changes in the 15bit numerical range, when I make adjustments.

[Graeme Nattress]

If you just need to create test patches into 16bit file, I'd write a small c app to generate a "raw" image, and encode in the precise values you need. It may sound like a bit of a pain, but it's probably the only way to guarantee the accuracy you need.