You can look into whether there are settings in the nVidia driver’s control panel that let you set the black level or brightness curves. Some people have found that there are adjustments that help, some have found that the controls do not help.
The problem here is that we really want the digital signal to go from the Windows graphics layer out to the projector over HDMI with no alteration. But on some video cards, particularly the fancier ones, there’s an adjustment layer that can’t be bypassed to make images look “better” that works against us when using the image as a light source for printing.