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View Full Version : Nikkor Process 210mm f10, additional thoughts.



Tito Sobrinho.
8-Oct-1999, 02:28
Hello: Thank you for trying to help me on this mysterious lens. The design of th is lens, does not go along with your thoughts. At the same day that I made my qu ery with you'll, I contacted Nikon USA and they did not know about it existence. Let me describe it: Short barrel (65cm). Wt.of 500 Gm (1/2 kilo). F10 to f32. S ymmetrical and multicoated but does not follow a common modern design i.e airspa ced Dagor (Plasmat) or Tessar or Heliar or double Gauss or Biogon or a modified Triplet. The front and back elements have the curvature of a "fisheye" lens that protrudes 8mm above the respective flanges. It is like the curvature of the Goe rz Hypergon but larger in diameter. Both lens caps are conical in order to acomm odate the curvature. If I want to use a filter, I have to set it on the lens hoo d. Front flange measures 63mm and the lens hood has a height of 2cm with a exter nal opening of 90mm. As you can see, the lens hood follows a wide angle design. Shining a fluorescent tube on the front and back cells, I can see 3 menisci on e ach side. Is this a modern Metrogon&Topogon? Bush Pantoskop? Harrison's Globe le ns? in other words a computer corrected Meniscus anastigmat? Today, I mount it o n my 8x10 and indeed it is a wide angle but lighter and smaller than my 210mm An gulon with the same coverage. I am going to expose a 8x10 Polaroid a la Sally Ma nn (Hat as Shutter) and see the results. Thank you for your patience. Appreciate . Best, Tito.

Erik Ryberg
8-Oct-1999, 13:05
Tito,

Yes, this is the same as my lens, only mine is 260mm focal length. I mount a gel filter in my camera, behind the lens. I also have some old glass filters that fit in the lens shade but I haven't tried them yet. You see these lenses on ebay from time to time. There must be a surplus supplier of them somewhere. I will be very interested to know if the 210 covers 8x10, so let us know. I have emailed a few sellers of the 210 with this question and they never answered, which made me assume it did not. The 260 looks like it has about an 18" image circle, which is far short of what a Hypergon type design would produce. The bulbous lens elements are definitely strange, though.

Erik

Michael Phifer
19-Oct-1999, 23:31
Sounds like it could be a Metrogon or Topogon. These were extreme examples of th e double-Gauss design (Four air spaced Meniscus-lenses). These ultra wide lenses were used for many years as the standard aerial lens before and after WWII. The y were claimed to Cover 90 Deg at f6.3. Where as the standard double-Gauss (i.e. Kodak Wide Field Ektar, Meyer Aristostigmat) covered 90 Degrees at f22 or so.

Mike Phifer

Tito Sobrinho.
20-Oct-1999, 01:34
Hello, Mike: Yes, the mysterious lens design came to an end. Yesterday, I got the specifications from the previous owner. He sent me a Fax of a page dated 1977 (Nippon Kogaku) with a drawing of the whole lens. You are absolutely right. It is a modern multicoated computerized version of the Metrogon & Topogon design i.e. 2 menisci in 4 groups and not 3 in 4 groups like I had previously thought. Best wishes, Tito.

Tito Sobrinho.
20-Oct-1999, 08:04
Erratum: In my previous comments, concerning the 210mm f10 Nikkor "3 elements in 2 groups", should read 3 elements in 6 groups. Thank you. Tito

Michael Phifer
20-Oct-1999, 23:10
Tito,

Always good to read your replys, I am glad to have been of some help in return.

I like my Meyer Aristostigmat on my 4x5 it is plenty Sharp at f16. I know that K odak Advertized the wide field Ektar for "Color Separation Work" at f16 !!! Thes e guys are very light and small.

They do have a drawback on Light Fall Off (Cosine Law). A Biogon (Super Angulon, etc)Design is some what Self Correcting in light fall off. A double-Gauss is no t. The Biogon's Optical Apature actually gets larger in diameter as you get off axis. This helps compensate for the cosine light fall off.

Try your lens. I hope you will like it! I just expose a bit more to assure enoug h exposure in the corners. Then burn the corners during printing.... Mike