Canon LTM Canon Rangefinder Lens Designers

[CanonRFinder]

HI,

I was trolling through the various threads last week and someone asked who designed Canon screw mount lenses?. I forgot where I saw it so decided on a new thread as some maybe interested. Most of the designers are named in a Japanese "Canon Rangefinder Camera" book by Yoji Kawasaki. Some I had to search for via the USA Patents Office on the web. I have named the original designers for the lenses even though they may not have been working for Canon later on as the lens developed. Peter K

Designer​

Lens ​

Mr Hiroshi Itoh .............28mm f/3.5
Mr Hiroshi Itoh.............. 28mm f/2.8
Mr Hiroshi Itoh ..............35mm f/3.2
Mr Hiroshi Itoh ..............35mm f/2.8
Mr Hiroshi Itoh.............. 50mm f/1.2
Mr Hiroshi Itoh ..............50mm f/1.4
Mr Hiroshi Itoh ..............50mm f/1.8
Mr Hiroshi Itoh ..............85mm f/1.5
Mr Hiroshi Itoh ...............85mm f/1.9
Mr Hiroshi Itoh ...............100mm f/3.5
Mr Hiroshi Itoh ...............135mm f/2.5M
Mr Hiroshi Itoh ...............200mm f/3.5M
Mr Jirou Mukai ...............25mm f/3.5
Mr Jirou Mukai ...............35mm f/1.5
Mr Jirou Mukai ...............35mm f/1.8
Mr Jirou Mukai ...............35mm f/2
Mr Jirou Mukai ...............50mm f/0.95
Mr Jirou Mukai ...............50mm f/2.2
Mr Jirou Mukai ................50mm f/2.8
Mr Jirou Mukai ................85mm f/1.8
Mr Jirou Mukai ................100mm f/2
Mr Jirou Mukai ................135mm f/3.5
Mr Masana Kuroki........... 35mm f/3.5
Mr Masana Kuroki. ...........50mm f/1.5
Mr Masana Kuroki. ...........50mm f/1.9
Mr Masana Kuroki. ...........8.5cm F/2
Mr Masana Kuroki. ...........85mm f/2
Mr Masana Kuroki. ...........10cm f/4
Mr Masana Kuroki. ...........100mm f/4
Mr Masana Kuroki. ...........1000mm f/11
Mr Masana Kuroki. ...........400mm f/4.5
Mr Masana Kuroki............. 600mm f/5.6
Mr Masana Kuroki. ...........800mm f/8
Mr Ryouzou Furukawa .....5cm f/2 SK & CCCo
Mr Ryouzou Furukawa ......5cm f/3.5 SK & CCCo
Mr Ryouzou Furukawa ......50mm f/3.5
Mr Ryouzou Furukawa .......5cm f/1.5 SK X-Ray lens and was adapted to fit J & JS
Mr Ryouzou Furukawa .......75mm f/4.5 SK
Mr Ryouzou Furukawa .......13.5cm f/4 SK & CCCo
Mr Shuji Koyanagi .............19mm f/3.5

 

[Sonnar2]

THANKS. Some of these lenses have been even patented in Germany, i.e. 85/1.5, the 85/1.8 and the 35/1.5. You may ask why Leitz didn't build a short-build, low-weight Summicron 90/2 in the 60's? Maybe because of Canons patent on the 85/1.8! Some of the Canon designs were among the best of their time even when compared to Leica and Zeiss, which designers were famous stars at their time and legends nowadays. Who, on the opposite, has even heard about Jiro Mukai or Hiroshi Ito? Do a Google search!

But not just the lens designers of Canon were smart engineers. Look at this patent for a TTL-metered rangefinder camera 1957, 13 years before Leitz came up with a similar solution for the M5! Nikon RF people be proud of prototypes like the SPX whereas Canon guys don't even know about the developments Canon did in that overheated, crazy era of the late 50's.

 

[harry01562]

Thanks, Peter, for the list of designers. It was interesting to note that designer of the 0.95 also did the famous trio of 35's and the fabulous 100/2. Also that the 85/1.5 was just one of so many good to great lenses by one designer.

Canon had some all stars working at that period, without the benefit of computers, which must make things at least a bit easier.

Any idea when we can expect to be able to order the very anticipated book? Some of us have been waiting a long time, and still look forward to it.

Harry

 

[CanonRFinder]

HI Harry and Sonnar,

I had noticed a wealth of info on Canon patents while I was trolling through the net and was amazed what was going on as well. I have bookmarked some of them and will refer to them later on.

For the past three months FRUSTRATING is the only word for me. The manuscript has been completed and all the photos are ready to be placed in the layout BUT the young chap took of at the end of May for a job overseas in China and Singapore. It is at the stage where the cover has to be designed (have an Idea) and everything just has to be put in place...BUT.......

Spent to many $$$$ to take it anywhere else so I literally I twiggle my thumbs but hopefully Joel will be back early September. I know there are many sceptics out there but it will happen. Peter K

 

[dexdog]

Peter K, I am looking forward to your book.

Also, it is surprising to see that Canon, like Zeiss, had a small number of stars when it came to lens design. Of course, some of the credit has to go to the staffs working under the designers.

 

[airds]

Peter

Would some advance orders - I'm sure they'd be a few here - help with the cash flow?

b.rdgs

 

[CanonRFinder]

SO AM I

Many of the original designers had left Canon and some lenses were recalibrated, the 50mm f/1.9 lens is one that comes to mind. This lens and the 5cm f/2 are the only early lenses (pre late 1951) where two lenses with diffrent focal lengths were on sale at the same time and using the same serial number range. Both started at 20000. This is the reason why the 5cm lens stayed with the centimeter designation and the 50mm f/1.9 was issued in millimeters after April 1949.

 

[CanonRFinder]

Peter

Would some advance orders - I'm sure they'd be a few here - help with the cash flow?

b.rdgs

When I have the disc in hand and ready to go to the printer then I will accept pre orders BUT not until then. This has been one HELL of a learning curve for me but have enjoyed it.

Thanks for the thought and THAT will be a big help when the time comes.

 

[David Murphy]

I'm not sure they were totally without the benefit of computers. Optical raytracing was an early and important task given to the first accessible mainframes (primarily IBM mainframes). I've seen a review article (in English) on the subject of computer based optical design published in the 1950's where machine code programming was deployed to trace rays. My guess is that the major Japanese camera makers like Canon got their hands on these computers just as soon as they could. It would be interesting to know just exactly how and when that occured.

Thanks, Peter, for the list of designers. It was interesting to note that designer of the 0.95 also did the famous trio of 35's and the fabulous 100/2. Also that the 85/1.5 was just one of so many good to great lenses by one designer.

Canon had some all stars working at that period, without the benefit of computers, which must make things at least a bit easier.

Any idea when we can expect to be able to order the very anticipated book? Some of us have been waiting a long time, and still look forward to it.

Harry

 

[wlewisiii]

When I have the disc in hand and ready to go to the printer then I will accept pre orders BUT not until then. This has been one HELL of a learning curve for me but have enjoyed it.

Thanks for the thought and THAT will be a big help when the time comes.

I don't suppose you need any proof readers? :angel:

I'm looking forward to the day when I'll have your book on the shelf with my other Canon books. Thanks for all this work you've put into it.

Thanks as well for this designer list - I'd known a few of them but was also amazed at the small number of designers.

One curiosity, for me in the list, is the listing of two different lenses - 5cm/1.5 & 50mm/1.5. Different ways of saying the same thing or different designs with the 50/1.5 being the familiar Sonnar based design?

Thanks!

William

 

[xayraa33]

the 5cm f1.5 would be the Seiki Kogaku of the war years , made for the Seiki x-ray cameras but adapted to the Canon JS and S-II cameras later on.
the 5cm lens would have been of a slightly different design then the 50mm/1.5 of the early 1950s.

 

[wlewisiii]

the 5cm f1.5 would be the Seiki Kogaku of the war years , made for the Seiki x-ray cameras but adapted to the Canon JS and S-II cameras later on.
the 5cm lens would have been of a slightly different design then the 50mm/1.5 of the early 1950s.

Thank you for the reminder, I'd totally forgotten about the x-ray cameras. Looking at the list and remembering when several of the other lenses each designed came out points to this as well... :bang:

Thanks!

William

 

[CanonRFinder]

I'm not sure they were totally without the benefit of computers. Optical raytracing was an early and important task given to the first accessible mainframes (primarily IBM mainframes). I've seen a review article (in English) on the subject of computer based optical design published in the 1950's where machine code programming was deployed to trace rays. My guess is that the major Japanese camera makers like Canon got their hands on these computers just as soon as they could. It would be interesting to know just exactly how and when that occured.

I will check with Hayato in Japan who may know or even Peter Dechert, I will ask them both as I to would be interested. It may take some time but when I do I will add it to this thread. Peter

 

[Sonnar2]

Probably Furukawa, Kuroki and Hiroshi Ito calculated most, if not all of their lenses without the help from computers, but not Jiro Mukai. ray-tracing calculations have been a classical usage of computers right from the beginning. Leitz Rechenbureau installed a Zuse Z5 (which number means it was the 5th German computer, incorporated 2,200 relais) in 1953. Carl Zeiss Jena used a East-German Oprema (17,000 Relais) in 1955 - Zeiss Oberkochen a Zuse Z-22 in 1957. Voigtländer either had a computer in Braunschweig or used it from Zeiss. Anyway Tronnier's Rechenbureau (freelancer for Voigtländer and Isco) had access to a computer.

I'm quite sure that Canon, Nikon and Pentax used computers as well for optical calculation in the late 50's, leave alone for the speed they launched new lenses. Otherwise they would need to have 1,000 people to do the calculations. I remember seen a picture of a computer of a Japanese company in the 50's but cannot remember which it was. Frank

 

[CanonRFinder]

I don't suppose you need any proof readers? :angel:


Thanks for the offer but I am very lucky in that department that my Daughter-in-law is an editor and proofreaders and has managed to improved my writing and grammar exponentially.

 

[CanonRFinder]

Probably Furukawa, Kuroki and Hiroshi Ito calculated most, if not all of their lenses without the help from computers, but not Jiro Mukai. ray-tracing calculations have been a classical usage of computers right from the beginning. Leitz Rechenbureau installed a Zuse Z5 (which number means it was the 5th German computer, incorporated 2,200 relais) in 1953. Carl Zeiss Jena used a East-German Oprema (17,000 Relais) in 1955 - Zeiss Oberkochen a Zuse Z-22 in 1957. Voigtländer either had a computer in Braunschweig or used it from Zeiss. Anyway Tronnier's Rechenbureau (freelancer for Voigtländer and Isco) had access to a computer.

I'm quite sure that Canon, Nikon and Pentax used computers as well for optical calculation in the late 50's, leave alone for the speed they launched new lenses. Otherwise they would need to have 1,000 people to do the calculations. I remember seen a picture of a computer of a Japanese company in the 50's but cannot remember which it was. Frank

Hi Frank,

Very interesting info.

I had a quick glance at the number of lenses Canon introduced in a certain year and 1956 was a big year as they released seven lenses between January and April of that year.

Six new focal lengths and the 50mm f/1.8 was restyled and maybe redesigned as they went from 10 blades in the T4 to 11 blades in the T5 lens.

[FONT=&quot]If Leitz installed a computer in 1953 then it is possible that Canon installed a computer in 1955 with the results in 1956. Be interesting to find out who manufactured the computer. Be also interested to see how any lenses Leitz, Zeiss and others introduced after installation of there computers.

These computers must have been HUGE.
[/FONT]

 

[wlewisiii]

If Leitz installed a computer in 1953 then it is possible that Canon installed a computer in 1955 with the results in 1956. Be interesting to find out who manufactured the computer. Be also interested to see how any lenses Leitz, Zeiss and others introduced after installation of there computers.

These computers must have been HUGE.

Fujitsu shipped the first Japanese produced computer in October 1954 (FACOM 100) - it would not surprise me to learn that Canon was a very early customer. That would certainly be the right time frame for a massive boost in ray tracing speed to bring out the explosion of lenses in 1956.

William

 

[Sonnar2]

Hi Frank,
These computers must have been HUGE. [/SIZE]
[/FONT]

The Zuse Z5 at Leitz (weight 2 tons):

http://irb.cs.tu-berlin.de/~zuse/Konrad_Zuse/de/Rechner_Z5.html