Just to explain it for you:
F/2 = fast
F/1.8 = about as fast as consumer glass gets
F/0.95 = absurdly fast
F/0,7 = fastest lense ever made, Zeiss made 10 of them, most owned by NASA, two used by Kubrick to shoot 100 ISO film at 24 fps at candlelight.
The Zeiss Planar F/0,7 50mm is priceless