View Full Version : Does anyone have information on the Yamasaki 320 f/9 Apo Congo?

17-Nov-2018, 07:28
Yamasaki Apo Congo ? Anyone have any info on these lenses?

Steve Goldstein
17-Nov-2018, 14:46
I'm afraid this doesn't answer your question, but it may be of interest to others...

The original Congo web site is gone but it's viewable in the Wayback Machine: http://web.archive.org/web/20120419205958/http://www.cosmonet.org/congo/index_e.html

I didn't see any mention of the Apo Congo line, though.

Kerry sold a couple of 260mm f/10 Apo Congo in Prontor SVS shutter some time ago, and I've seen one other in shutter and one in barrel on eBay in the recent past, but never a 320mm f/9 over several years of watching. Is it in a barrel or a shutter?

Maris Rusis
17-Nov-2018, 16:37
I have a 1991 dated listing for the Apo-Congo 320mm f9 lens. The details are:
Focal length: 320mm
Film format size: 8"X10"
Smallest f stop: 64
Shutter: Copal #3
Angle of View: 53 degrees
Image circle @ f16: 370mm
Front lens mount diameter: 52mm
Rear lens mount diameter: 52mm
Overall length: 40mm
Distance from shutter to end of rear mount: 7mm
Distance from lens seat to film plane: 298mm
Back focal length: 294mm
Filter size: 49mm
Weight: 530g
Catalogue number: 198

Optically the lens is described as a symmetrical 4 element 4 group apochromat designed for process and reproduction work.

Yamasaki was a small company with an extensive lens line so particular lenses like the 320mm f9 were produced in short run batches from time to time. Exact details and specifications could change a bit between batches.

17-Nov-2018, 17:25
Over the years have owned and tried out (borrowed) several Congo lenses. Some were great and others only so-so. Assume a quality control problem with their "short runs". Test before you buy highly recommended.

17-Nov-2018, 19:26
There is one listed on eBay (item number 123494990106) for anyone interested.

PS: I donít have any affiliations with item or seller. Just have not seen one of these before.

Itís a shame itís in copal 3... could it be mounted in copal 1 or 0?

Also at 320 itís in competition with the Fijinon c 300...

Sent from my iPhone using Tapatalk Pro

Dan Fromm
18-Nov-2018, 07:53
It’s a shame it’s in copal 3... could it be mounted in copal 1 or 0?

Probably not without expensive machining. Front mounting it on a #1 or an Ilex #3 would cost less and might work.

The coverage claims in post #3 above seem inconsistent. 320 mm, 53 degrees means a 319 mm circle. 320 mm, 370 mm circle, means 60 degrees. Apo Ronars and dialyte type Apo Nikkors cover considerably less than that, and there's a hint.

Steve Goldstein
18-Nov-2018, 15:24
Maris, do you have similar information for the 260mm f/10?

Maris Rusis
18-Nov-2018, 21:08
Maris, do you have similar information for the 260mm f/10?

Yes! The information I have dates from when I sold Tachihara cameras in Australia. The Yamasaki Optical, Osaka connection happened because I was looking for good but economical view camera lenses from other than the big four: Schneider, Rodenstock, Fuji, and Nikon. Yamasaki like a lot of small to medium Japanese companies didn't want to set up an English language sales department so they exported through Shiro Trading Company. Shiro did the English translations of the Yamasaki technical lists but since Shiro knew nothing (!) about lenses there are occasional errors.

Apo-Congo lens 260/10
Focal length: 260mm
Speed f/: 10
Film Size Format: 61/2 X 81/2. Whole Plate
Smallest f/ stop: 64
Shutter: #0
Angle of View: 53 degrees
Circle of Image f/16: 300mm
Front lens mount diameter: 42.5mm
Rear lens mount diameter: 32mm
Overall length: 47.6mm
Distance from shutter to end of rear mount: 19.6mm
Distance from lens seat to film plane: 261.6mm
Back focal length: 245mm
Filter size: 40.5mm
Weight: 290g
Catalogue number: 172