1. Load your 16 bit map up in Photoshop, go to mode -> 8 bit. Thats it, resave the file and you'll have your dithered 8 bit map. 2. You can sort-of dither from an 8 bit source. First, bake at 2x the resolution, then open it in photoshop, set it to 16 bit (mode -> 16 bit), then resize it to half, and then convert back to 8…