150mm lens design
Posted: Sat Feb 17, 2007 5:07 amHello everyone!
I'd like to know - is the 150mm lens of Sonnar or tele-tessat design?
Thanks
Mikhail
I'd like to know - is the 150mm lens of Sonnar or tele-tessat design?
Thanks
Mikhail
Hi Mikhail,
When I read your post, I had a closer look at the diagrams for the 150 and 180mm lenses. Then I realized that all the lens diagrams from Fuji were inverted compared to the usual lens diagrams. Conventional representations of lenses have the subject on the left and the image on the right, while Fuji diagrams are drawn the other way round.
I mistakenly wrote on the "Lenses" page that the Fujinon-T S f:5.6 150mm was a modified Tele-Tessar design, because I thought that the cemented doublet was part of the rear group, as this is usually the case with the Tele-Tessar design. As this doublet is in front, the lens is definitely not a Tele-Tessar.
What about a Sonnar? There are many types of Sonnar lenses with rather different designs, but they usually have in common a cemented triplet behind the stop, which is clearly not the case with the Fujinon and its rear group comprising 2 separate single elements.
The design of the Fujinon looks very much alike the Cooke Distorsionless Telephoto (R. Kingslake, Lenses in Photography, Garden City Books 1951, p. 133). Its front doublet is also reminiscent of the 3.7 Kodak Ektar. I don't know whether this telephoto design was also used by other Japanese manufacturers.
If anybody has details about the design of these Fujinon lenses, please chime in.
Cheers,
Sebastien