Given such low output and low contrast it's not likely to do much better. In short, shop for a bettery display or use it in not so bright spaces.
I've had this monitor for quite awhile (HP Compaq LE1911.)
It has never adjusted well. Not via "auto" or selecting "brightness" or "contrast" which both read 100%. I think that I've played around with every single setting possible.
It didn't bother me overmuch until I had to move my desktop to a bright sunroom. Now it's impossible to see. The screen is very dark. I think the contrast would be ok, if I could only see the screen better.
Can anyone help?