1st. test, Grandigon-N vs. Biogon.

[richard_boulware]

Last year I purchased a new 75mm 4.5 Grandigon-N. This year I purchased a classic 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 Grandigon-N is a fine lens. Our first black and white film test certainly proved that. The 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 microscope 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 were looking at sections of the negative that were only 5mm. The Biogon show some gray scale separation, but not as much. Please remember that we were looking at details of windows and doors in houses two blocks away.

The Grandigon-N, DID photograph about 1/8th." of the front bed of the Super Technika 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 conclusion = The Grandigon-N is a superb lens, but to our surprise, the Biogon is one 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 would 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.

[jim_galli4]

Thanks Richard. That is an interesting comparison. The Biogon's are

famous for being as good wide open as closed down. Be sure to do a

comparison of both at maybe f8 and see what you get. My "poor man's"

Biogon is my 50mm f6.3 for the Mamiya Universal. It's my hands down

choice for night shots because at f8 I know everything from 6 ft. to

infinity is going to be SHARP! I can do moonlight shots on Velvia

with that old camera.

[thilo_schmid1]

Richard,

 

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thank you for sharing your experience. The design of the Grandagon

and the Super-Angulon are actually derived from the Biogon. I would

expect that the modern Grandagon-N does perform better at lower

apertures and thus deliver more resolution. Have you done test shots

with different apertures? Viewing an LF negative thru a microscope at

20x magnification will not show you much fine details, if your

picture was taken at f22. Also remember that the admissable circle of

confusion is usually stated as 0,1mm for 4x5". Any details below this

are only recognizable on murals.

 

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Since negatives do have gamma values <1, you might not be able to

recognise some of the details, since the ability of your eyes to

distinguish grey values is limited compared to photographic paper

with gamma >1. A gradation 5 paper might easily reveal details you

cannot see under a microscope.

 

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Regards,

[steve_fox]

Folks, the only thing I want to say is, Biogons are not Retrofocus design. It's true quasi-symmetric design. Grandagons and Super Angulon are basically a Biogon design but I don't know who got this design first (i.e. Zeiss, Schneider or Rodenstock ?) Zeiss Distagons are Retrofocus design and can be mounted on a SLR.

Stev