Any knowledge/experience with a Konica (Rukuoh-sha) Hexar Series 1 25cm 4.5 lens

[Ed Haertel]

I have one of these Rukuoh-sha Tokyo 250mm lenses in barrel. While I'm aware of Konica's reputation for the Hexanon lenses, I haven't found any information about this lens (or this series of lenses). It most certainly is a lens intended for LF use, about 1.5 lbs and the rear element is just short of 3" across. I briefly gave some thought to this being a repro lens, but while the barrel has an odd configuration for the rear element mounting, the aperture range (4.5 to 32) would seem to remove it from the "norm" of copy lenses. Has a sort of bayonet mount (3 studs on lens and turning cam slots on the filter) filter of orange yellow (or yellow orange) glass, marked "Rukuo-sha Colour Filter". Any info would be appreciated.

Ed

[Dan Fromm]

WW-II (possibly earlier) aerial camera lens.

Please put it on a Speed Graphic or in front of a shutter, try it out, and report.

Cheers,

Dan

[Ed Haertel]

I gave aerial lens some thought, and (with your clue) this morning found a Japanese J8 1942 vintage aerial camera listed on Classic Camera.org's website with what might be precisely this lens. Lens detail was lacking, (to include the inability to read the lens marking) other than the page listing the maker/model detail and serial # of the lens. Apparently the camera's shutter reduced the maximum aperture as the nomenclature plate on the camera shows it as f8 while the page lists the lens as f4.5. What little I could see of the mount (front of lens only and without the filter mine has,) tends to make me think mine has been converted to "normal" LF use, which would explain the unusual mounting in barrel. While the aerial camera appears to have the f stops visible from the front of the lens, on my lens they are visible from the side (and would have been impossible to see with the lens mounted in this particular camera). The mounting on my lens looks like a bare metal barrel with some form of helical "threading" visible through some screw slots in the outer barrel. My initial impression was that this inner barrel was intended to provide an ability to focus the lens, and from the pictures of the aerial camera, I'd say that impression was confirmed by the distance marked ring at the front of the camera. This "inner" barrel is mounted within an outside, appears to be newer, painted (gloss black) barrel with some screws holding the inner barrel near the rear element. The outer barrel has a "standard" flange for mounting, plus some sort of tabbed ring immediately under the flange, the function of which escapes me so far.

In any event, I'm not at home and won't be for a while. When I have time to put this in front of a Packard, I intend to find the coverage (up to 8x10 anyway) and see what it will do. Will post the results, though it will be some time.

[Ed Haertel]

Now that I've had some free time, a little more digging (OK, surfing) finds:

"In 1902, Konishi Honten established Rokuoh-sha in Tokyo, which was a division dedicated to the production of photosensitive materials and later photographic equipment."

"In 1931, Mohri Hirowo of Konishiroku Honten Co. produces a f/4.5, 4-element H-type lens with Jena glass. The lens, named "Hexar," was based on the Carl Zeiss Tessar lens. "Hex" is for Sugiura Rokuemon where "Roku" means six. The lens was a success and claimed equal performance to the Tessar lens. The "Hexar" label was used on Konishiroku's top-quality lenses up to 1959, when the lenses were renamed Hexanon."

Sounds promising. With thanks to "Denis' Photography Pages".

Ed

[Ernest Purdum]

My first thought, like Dan's, was that it was an aerial camera lens, but the focusing mount, makes that unlikely. You are correct in thinking that an f4.5 aperture is too large for a process lens. One possibility is that is was intended for a strut camera. While in the United States "press camera" meant a Speed Graphic, in the rest of the world most newspaper people were using strut cameras like those made by Goerz and Ernemann amongst others including Konishi, the Rokuoh-sha parent company. Most of these used lenses mounted in a focusing "sunk" mount (the flange well forward on the lens barrel so that most of the lens was inside the camera). 250mm would be a very large focal length for one of these though. It implies a "whole plate" (6 1/2" X 8 1/2" camera. A strut camera of this size would be very cumbersome to use.



I am guessing that your lens probably was military, though more likely for ground use than aerial. The Rokuoh-sha works, like other high-quality Japanese optical facilities, was heavily engaged in military prduction before and during WW II.

If the flange is toward the front of the lens, so that most of the lens wpi;d be inside the camera body (sunk mount), the lens was perhaps that produced for a Konishi (Konica) strut camera, although the 250mm focal length implies an unusually large one, probably "whole plate" (6 1/2" X 8 1/2"). While in the United States "Press camera" meant a Speed Graphic, elsewhere the favorite tool of newspaper people was a strut camera of the sort made by Goerz and Ernemann amongst others, although usually not larger than 13 X 18cm. A whole-plate camera of this design would have been very cumbersome and the limited depth of field would hav made it difficult to use. In most of these, including the Konishi, focusing was done by a helical lens mount. Konica used the name "Idea Spring Camera", but there may have been other model names.

As you surmise, an aperture of f4.5 would leave out the possibility of your lens being a process type. It may well, however, been a military lens as the better Japanese optical works, including the Rokuoh-sha works, were heavily engaged in m

[Ernest Purdum]

Aaarggh. Computers. The preceding is a composite of two answers, one of which I thought had been lost by a glitch. How the two got pasted together is far beyond my understanding. Sorry for the redundancies.

[Ed Haertel]

See

http://www.classiccamera.org/j-8%20aerial.htm

for the above referenced J-8 aerial camera, which at least used the cells from this lens. Note the focusing scale pictured on the "nose" of the camera. That sort of set-up could account for the helical on the rear half (guess as to the total) of the inner barrel of my lens, or any other type of rotating lens focusing. That being said, the aperture scale on mine would not work on the J-8 camera as it reads from the side and not the front. Apparently the 250 f4.5 lens was produced in several configurations and a barrel mount isn't utterly rare, Goodwin Photo has one listed in barrel.

Amazing what you can find on the net when you know the correct spelling! :-)

Ed