My early trys at Ortho Lith was its really slow, as other have said ISO3 but suffers badly from reciprocity making pinhole exposure really loooong. I was rating it ISO1 in bright day light with a f333 pinhole (200mm 8x10) and was still under exposing. The 3rd and 4th images under "resent" in the pinhole link below are Ortho Lith (Arista ll)