I have moved away from 8x10 for field use but back in the day I used a 150 SSXL, 210mm Sironar W, and 360 Sironar S... All three were very sharp. I think the 210, and 360 were slightly sharper but other factors could have been at play. At the right aperture I'd say these lenses are capable of roughly 3000PPI (based on high resolution scans and my 10x Schneider loupe).