Another factor for Digital: LTM lenses were designed for Film, including the 35/1.7 Ultron LTM. At F4, the Ultron was measured at 90lp/mm. I have a copy of the Pop Photo test of the lens. Wide-open, lower contrast. It will not do as well on a Front-Side Illuminated CMOS sensor as it does on the Back-Side Illuminated KAF-18500 used in the M9.