Richard Boulware
4-May-2002, 15:31
Last year I purchased a new 75mm 4.5 Grandigon-N. This year I purchased a classi c 75mm Zeiss Biogon. I must emphasize that this is only the first of many test I will do comparing these two fine lenses. First off, let me say that Bob Solomon is on target when he told me the Grandigo n-N is a fine lens. Our first black and white film test certainly proved that. T he surprise was how close the classic Biogon came to matching the performance of the superb Grandigon -N. Test were conducted on a bright sunny Colorado day at a test target and buildings about two blocks away with plenty of detail in both sunlight and shadow. Negatives were observed through a binocular disecting micro scope at 20X with transmitted light built into the microscope. On the plus side, the Grandigon-N showed greater micro contrast. By this I mean that tiny details and delineation of similar shades of gray could be observed, even though we wer e looking at sections of the negative that were only 5mm. The Biogon show some g ray scale separation, but not as much. Please remember that we were looking at d etails of windows and doors in houses two blocks away. The Grandigon-N, DID photograph about 1/8th." of the front bed of the Super Tech nika V, focused at infinity and in the horizontal mode. The Biogon...because of it's massive front element and retrofocus design did not do this. 1st. step conc lusion = The Grandigon-N is a superb lens, but to our surprise, the Biogon is on e helluva 30 year old relic. No wonder it was so expensive. My Biogon is one of the first production lenses of the third, and final production series that Zeiss made for Linhof, and mine IS a Linhof engraved lens. On a 1 to 100 scale, I wou ld rate the Grandigon-N as a 95 and the Biogon as 88-90. Not bad for a 'relic'. Color test and other test coming soon. Just thought I would share this with the group. Best regards, Richard Boulware - Denver.