Mac Pro + Dual 27″ Cinema Displays brightness & brightness control

Hardware:

• Mac Pro 4.1 (circa 2009)

• AMD Radeon HD 7950 3072 MB graphics card

I have just connected dual 27" Cinema Displays.

Both work, lots of display space 😉

Two problems (perhaps related):

1. F1 & F2 keys only adjust brightness on the primary display.
2. 2nd display about (purely estimated) 92% of the brightness of the primary display and just a bit too dim to feel comfortable. While perhaps just the difference in ages and use of the 2 displays, I wonder if something else might have gone awry?

Any way to adjust brightness of both displays from my keyboard?

Any other adjustment I can make to the brightness of the 2nd display.