design of fujinon 55mm f/2.2 lens

Hi All,

I am curious to know about the design of fujinon 55mm f/2.2 lens. It
is listed as 4 element in 4 groups.
So, it does not make it a Tessar type lens, tessars usually being no
faster than 2.8.

It is not also a double Guass design.

Fuji has another 55mm lens which is of traditional design, 55mm f/1.8.

Could anyone provide more information about this lens? Is it expected
to perform as well as a 6 element lens, and did any other manufacturer
produce similar lenses?

thanks for any information,
Sreenath

 

I can't really help, but I did once own a Fujinon 55mm 1.6 (on a
Fujica ST605, then an AZ-1). Very fine lens although a little prone
to flare - I recall it had an unusually curved front element. Fuji
seem to do their own thing quite frequently...

 

Sorry to say, the Tessar design consisted of 4 elements in 3 groups. The
front two were separate, and the back two were cemented.
Once upon a time, the max speed (with very good sharpness) of the Tessar
design was considered to be f3.5. Some companies have
sold f2.8 Tessars, but these were not the best around. Again, once upon a
time, the conventional wisdom was the 5 elements provided
the required number of degrees of freedom for good performance at f2.8.

I suppose I should mention the Zeiss Triotor f3.5 lens (I have an old
Rolleicord with one), but these definitely were not as sharp as
the Tessars. Triotars are cheaper though.

Perhaps someone wiho owns one of the subject lenses can comment about its
performance.

I would be surprised if it does; however, computer aided design of lenses in
conjunction with aspheric lenses can work wonders.

Jim

 

It is probably a symmetric [or close to] lens with 4 meniscus elements
arraigned around a central stop.

Sometimes called a '4-element Gauss' [and closer to what Gauss originally
proposed than the 6-elements that go by that name].

The design shows up in the Petzval portrait lens, some slide projector
lenses and in process lenses.

Basic principle is used in wide-angle view camera lenses like the
wide-field Ektars.

In this application it would be as a budget lens with a bit better
aperture specification than a Tessar. Should be very low distortion.

 

To add: Zeiss manufactured a very wide angle lens for the Leica which was
designed as Nicholas described. Examples of this lens are quite scarce and
very expensive.
It is also said to be very sharp and remarkably free from distortions.

Nikon also used such a symmetrical design for the 25mm f4 lens for use on
their rangefinder cameras. These lenses are also very scarce and expensive.
The lens was introduced
in 1954. Nikon did not remount this lens for the SLR cameras. It was
supposed to have been quite sharp and lacking in distortions.

However, it does not necessarily follow that the Fujinon lens will possess
the traits of these two predecessors.
Jim

 

No. The Petzval lens is nonsymmetric in the extreme. It has two
widely spaced positive two element groups, each of which is
semi-achromatic.


Doug McDonald

 

You're right ... one group is cemented(?)