On the cloud tops of Titan there's 72 times darker than on earth clowd
tops.
Earth's atmosphere passes through 63% of sunlight on a shiny day.
Titan's atmosphere is 10 times heavier and passes 10% of sunlight.

After a rough estimation, Titan's surface receives from 1/1000 to 1/500
of light which comes to Earth's surface.

It's in fact much darker than on a very stormy day, it's more like late
dusk, or at night, something like 20-30 meters away from a streetlight.
You'll really need some sort of artificial lighting there to feel
comfortable, and some serious cloth

Huygens cameras were specially designed to take piclures in such dark
conditions, so don't take those photos literally -- they don't depict
the real ilumination...

Some 3rd-party pics are he
http://anthony.liekens.net/huygens_static.html