A few weeks ago I was given a set of darkroom equipment, including a Kaiser VPM 6005 enlarger with 2 objectives, a Rodenstock Rogonar-S 1:4,5 75 mm and a Rodenstock Rogonar-S 1:2,8 50 mm. Untill now I was using a Meopta Opemus 6 Meograde enlarger with the EL-Nikkors 1:4 75 mm and 1:2,8 50 mm. I am switching from the Meopta (interested, anyone?) to the Kaiser enlarger but wonder whether I should stick with the Nikkors (they fit). I checked the Rogonars with a densitometer and saw that they have less vignetting than the Nikkors, but find it difficult to see any difference in sharpness and contrast as that is much more difficult to measure. I would appreciate it if anyone who has experience with these lenses would give an opinion on this matter. I mainly enlarge 4.5x6 negatives in my darkroom.