Looking for a long lens for my 4x5, I have seen this brand mentioned a few times. They have in particular a light 500 gr 4 elements 500 mm f9.5 with a 300 mm bellows extension costing $ 920. Any opinion?

-- Paul Schilliger (pschilliger@vtx.ch), February 20, 2000

Answers

It may be a Congo lens. They make a 500mm/F9.5. Here is thier site: http://www.cosmonet.org/~congo/index_e.html. One of our club members uses a 150mm Congo, and the images seem just fine.

-- Ron Shaw (shaw9@llnl.gov), February 22, 2000.

Thanks, Ron. The web site is worth visiting. I was bodered though by the conception of the lens I was interested for. It is very proeminent, perhaps 12 cm from the board and this makes me fear for shutter vibrations. Shan't I? Any user of this lens out there?

-- Paul Schilliger (pschilliger@vtx.ch), February 22, 2000.

Bromwell deals in Osaka lenses. Don't know if they are the same as Congo though. DJ

-- N Dhananjay (ndhanu@umich.edu), February 22, 2000.

Both Osaka and Congo (Yamazaki Optical Co.) lenses are tessar type lenses. I have a Congo 180 f/6.3 in a seiko shutter & it's fairly sharp. If you are considering a tessar lens, watch the coverage ~ that's the main drawback. I don't believe they are both from the same manufacturer in Japan.

-- Ted Brownlee (omfbh@aol.com), February 22, 2000.

After visiting the Congo Yamazaki Optical web site, I sent an email to them and was very kindly answered by Mr. Yamazaki himself. In a first answer he told me they where the makers of the OSAKA line of lenses. Then, answering a more specific question on the 500 mm and possibility of purchasing directly in Japan, I thought this would interest some of you, as I have found older threads on the same topic. Here is Mr. Yamazaki reply to me.

http://www.cosmonet.org/~congo/index_e.html

Thank you very much for your interest in our products.

500mm tele lens used to be F 8 full open aperture mounted on a big heavy number 3 shutter.

Abour 10 years ago,we have changed the design to the present one with F9.5 full open aperture mounted on a number 1 shutter.

The former is monolayer coated and has a image circle of 210mm, while the latter is multilayer coated and has a 160mm circle. As far as I remember,there is no F8 Osaka brand. Probably,the "210mm" you found is erroneously stated. You can easily tell which by the shutter, No.3 or No.1.

We are selling directly to an user. The shipping is by E.M.S.mail,a rapid air parcel. The payment is by bank transfer to our account in advance. If you let us know your address,we will let you know the total amount including shipping charge.

Thank you and awaiting to hear from you again. Keizo Yamazaki Yamasaki Optical Co.,Ltd. congo@cosmonet.org

-- Paul Schilliger (pschilliger@vtx.ch), February 26, 2000.

I always thought that my Osaka lenses were made by Congo. I have a 120mm f/6.8 tessar and a 400mm f/8 telephoto Both give superb results. Very sharp, but not much movement possible. The 400mm infinity focuses at about 240mm extention. I find this lens to be very useful. The image quality I get from these lens compare with what I get from my Nikkor and Rodenstock lens.

-- Leroy Beal (leroybeal@redshift.com), February 26, 2000.