C-Congo 180mm f/6.3 -- what do we know?

Does anyone have any information on the "C-Congo 1:6.3 f=180mm Yamaskaki Opt. Co." in a Seikosha SLV shutter? I believe it's the same lens as the Commercial Astragon 180mm f/6.3. I've seen pictures of both in the Seikosha SLV shutter and they look identical. Both seem to have been made by Yamasaki.

Some hints I've been able to find on the forum are here:
https://www.largeformatphotography.i...6-Congo-Lenses
https://www.largeformatphotography.i...-from-Yamasaki

There's very little information available on Yamasaki (Congo/Astragon) lenses in general, and this one in particular. I know it's a 4 element Tessar design. It's coated, likely single. But that's it. I've been told it covers 4x5 with very limited movements. I'm curious to know the image circle size and the weight of the lens. Thoughts on performance are welcome too.

Interestingly, the old Congo Lenses website from the late 1990s only lists a Commercial Congo 180mm f/6.8. There's no mention of an f/6.3 lens. The f/6.8 version had a big image circle of 220mm (presumably at f/22) and weighed a svelte 180g.

Congo website: https://web.archive.org/web/19981206...go/index_e.htm

It's a tessar design, so f6.3 would be more usual. Maybe the Copal #0 that website shows it in was limiting the aperture a bit.

I have an old brochure on some imported version of these from years ago I'll try to find. Some of their lenses also sold as Prinz and Osaka, though I don't know all the focal lengths offered. Nice performing "modern' tessars.

Quote:

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Originally Posted by Mark Crabtree

It's a tessar design, so f6.3 would be more usual. Maybe the Copal #0 that website shows it in was limiting the aperture a bit.

I have an old brochure on some imported version of these from years ago I'll try to find. Some of their lenses also sold as Prinz and Osaka, though I don't know all the focal lengths offered. Nice performing "modern' tessars.

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My Commercial Congo lens catalogue has this:
Focal length 180mm
Aperture range f6.3 to f64
Film size 5"x7"
Shutter #0
Angle of view 56 degrees
Image circle @ f16 is 220mm
Front lens mount diameter 42mm
Rear lens mount diameter 32mm
Overall length 33mm
Distance from shutter to end of lens 10mm
Distance from lens seat to film plane 167.1mm
Back focal length 159mm
Filter size 40.5mm
Weight 180g
In my September 1991 price list it is AUD$475.70

FWIW, I have the 180/6.3, in my case re-branded as a "Bogen-Arcar" in a Seikosha-SLV shutter as mentioned, #30095. Since it is a small and light lens, its the one I use if I am carrying my most stripped-down travel kit for my Canham 4x5, one lens and 3 40.5 size filters. It seems to allow for adequate movements, although most of the images I have made with it haven't needed large displacements. While my "gut instinct" tells me it is not as sharp off center as my more sophisticated Schneider or Rodenstock lenses, the 11x14 prints hanging on my wall look just fine, so unless you are making very large prints, or looking at the prints with an extremely critical eye, it serves its purpose (small and light) quite well.

As always, the forum is a goldmine of useful information and great advice! Thanks everyone. This is exactly what I needed to know.

I had Prinz branded 150 and 210 f6.3 that came with a used Prinzdorff when I first got into large format. I knew what the design was, but nothing about them so dropped by Lens & Repro with one of them when I was in NY. Jeff Kay (?) looked at it and he and another guy started chanting, "Congo, Congo, Congo". First time I'd ever heard of that, and not again for quite a while.

There was also a guy named Lee Beeder who was selling them out of Hollywood, CA engraved as Chromar N, W, & T for normal wide and tele. That is the old literature I have, and it gives the sames specs as Maris listed except listing image circle as 230mm @ f 22. The 180 f6.3 was listed in Seiko #0 shutter.

I had already met Ted Bromwell in Pittsburgh at that time, but it was a while later that he started to sell the Congo line as Osaka lenses (IIRC). I had one of those in 120 wide angle design, but didn't like it as well as the tessars. I should have one of his catalogs somewhere too. I've wondered what became of him and his business. Edit - I see they still have a website up, though no more Osaka/Congos listed: http://www.bromwellmarketing.com

Lee Beeder! He sold me (by mail) my first 4x5, a Tachihara, in 1982, from an address in LA. Haven't heard his name since.