Congo Lenses

[Maris Rusis]

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Found a sales brochure from the 1980s in the bottom of a filing cabinet. I don't think Yamasaki or Shiro are still in operation but the lenses are still out there and working.

[Maris Rusis]

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More Congo lens data recovered from faded and uncollated photocopies 1980s vintage.

[orgraph]

Thanks. Useful information. I had 90; 120; 400 mm lens. Nice, light, sharp.

[Vaidotas]

This is very nice to see in one place. Thank you.
But there is an older? f/4.7 and 6.8 congos too not mentioned here.

[Steve Goldstein]

Also not mentioned - 500mm f/9.5 Tele-Congo in Copal 1. 67mm filter, 70mm front cap, 51mm rear cap, overall length 150mm, image circle 160mm at f/22, 515 grams including caps and mounting flange, flange focal length 287mm.

This information comes from the old Congo Lenses site on the Wayback Machine here:

https://web.archive.org/web/20120419205958/http://www.cosmonet.org/congo/index_e.html

Interestingly, the archived site doesn't mention the 500mm f/8 in Copal 3 listed on one of the pages Maris provided. There may be other discrepancies, I didn't check carefully.

I've used my 500 once - my recollection is that I had a tiny bit of vignetting at f/22 with no movements so either the quoted image circle is generous or I just didn't have my lens perfectly centered.

Another one that doesn't show up anywhere is the 260mm f/10 Apo-Congo offered in (at least) a Seikosha SLV #0 shutter. Kerry Thalmann sold one on this list a few years ago.

https://www.largeformatphotography.info/forum/showthread.php?132862-FS-260mm-f10-APO-Congo-in-Seikosha-SLV-Size-0-Shutter

There was a longer APO-Congo, maybe 320mm f/9, on eBay a year or two ago but I passed on it because as I recall it had serious fungus. I believe it was in a #1 shutter.

[Maris Rusis]

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I'm not sure that the Soft Focus and the complex (non-tessar design) Alto-W lenses labelled Congo were actually made by Yamasaki. They could very well have been bought in and re-badged.

The image quality on the lens lists posted here is not so good because the original 1980s materials are photocopies made with blue toner on grey paper. I guess the information was considered somewhat proprietary and blue on grey would tend to defeat the photocopiers and fax machines of that era.

[Maris Rusis]

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[tomjohnson]

I have both the 150mm and 200mm Congo SF lenses. They are excellent, share some of the characteristics of their more famous ancestors, the Cooke Series II

[Greg]

At one time I owned and used a 400mm or a 500mm (can't remember which) Tele-Congo lens on my 4x5. Congo rated either focal length OK to cover 5x7, but in my experience my lens sharply covered the 4x5 format with just a wee bit of movement possible. Never used the lens on a 5x7. The projected image may have covered 5x7, but I'd doubt the corners of the 5x7 were all that sharp.