I've been trying to recreate some areas from HL2. So far the only HL2 to HL1 map I've seen is a recreation of Traptown.
Original: Demake: Obviously HL1 maps can't do impressive lighting as most of them just feel plain and blank. Goldsrc is a dated engine so it can't do too advanced lighting, but I'm talking about how far it can emulate HL2's level of lighting. Something with multiple tones of light, like this: