Car: Jag XF 3.0
Join Date: 10th April 2006
Thanked 2,774 Times in 824 Posts
When the headlights are off, it's in Day mode, and is bright (but day mode brightness can be set in the satnav - I have it on full all the time).
When the headlights are on, it's in Night mode, and is dim (but again there is a night mode brightness setting in the satnav, and once again I leave this on full).
Between day and night modes, it will remember different map colour schemes.
In night mode, if you turn the dash lighting twiddly knob up to full, then the satnav screen goes into day mode. This is to allow you to have your headlights on during the day, but still have the satnav fully bright.
So yes, as much adjustment as you'll ever need!