The "R" Series of Lenses

The SLR Era Begins

Single Lens Reflex cameras marked a decided change from the earlier rangefinder camera. Those cameras had no need for long “Flange Distances” as they had no mirror to rotate up out of the light path. This made for a more compact camera. However, two design requirements combined together to give rise to a new lens mount for the SLR Canon.

The first we just mentioned, the mirror swing. The lens had to be moved further from the film plane so that it did not strike the mirror. This meant redesigning the optics of the lens to focus further from the rear lens element.

The second was the “Through the Lens” (TTL) viewing. Focus was to be accomplished, manually in those days, with the light coming through the lens. The more light coming to the eye the easier this task. So it was desirable to have the lens remain at full aperture until the shutter was pressed. This meant that there had to be communication between lens and camera: the camera had to tell the lens when to close the aperture to the chosen f setting. There was absolutely no way to do this with the rangefinder lenses of the day.

The lens mount that Canon came up with was the “R” series mount which evolved over the next three decades into the FL series mounts, the FD series and the FDn series. The line only came to an end when automatic focusing demanded even more of the lens to camera communication and it became obvious that this venerable line of lens mounts was simply outpaced by technology.

The back of an “R” Lens showing the two operating levers that communicate with the camera body during the exposure cycle.

The mount itself was of the “breech lock” type and it is identifiable by a silver collar around the base of the lens. When the lens is lined up with the red dot registration mark and placed into the lugs on the body this collar turns to engage the locking lugs. It is turned until it is tight and friction holds the collar in place. The lens itself does not rotate during this procedure.

On the back of the lens there are two levers. The Cocking Lever is pushed by a corresponding lever in the camera when the film is advanced which puts the iris under tension but does not move it. When the shutter is pressed a second arm in the camera body pushes the Trip Lever which releases the Iris and allows it to close. It holds the Trip Lever until the shutter curtain is closed and then releases it. The iris then returns to its widest aperture.

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The "R" Series Lenses by Date of Issue

 

 No. Name Released Min. f/ Blades Groups Elements Filter Weight
 1  R 50mm f/1.8 (I) May 59 16 4 6 58mm 295gr
 2 R 135mm f/3.5 May 59 22 10 3 4 48mm 370gr
 3  R200mm f/3.5 May 59 22 8 5 7 58mm 670gr
 4  R 100mm f/2 Sep 59 16 6 4 6 58mm 515gr
 5 R 85mm f/1.9 Jan 60 22 4 6 48mm 355gr
 7  R 400mm f/4.5 Jan 60 22 4 5 48mm 1700gr
 8 R 600mm f/5.6 Jan 60 32 1 2 48mm 2100gr
 9  R 800mm f/8 Jan 60 32 1 2 48mm 1900gr
10 R 1000mm f/11 Jan 60 32 1 2 48mm 1800gr
11 R 135mm f/2.5 Feb 60 16 6 6 4 58mm 630gr
12 R 35mm f/2.5 Aug 60 16 6 5 7 58mm 317gr
13 R 50mm f/1.8 (II) Aug 60 16 4 6 58mm 305gr
14 TV 2000mm f/11 Sep 60 11 0 4 7 48mm 10,620gr
15 R 100mm f/3.5 (I) May 61 22 4 5 40mm 210gr
16 R 85mm f/1.8 Oct 61 16 8 4 5 58mm 470gr
17 R 58mm f/1.2 Feb 62 16 8 5 7 58mm 432gr
18 R 50mm f/1.8 (III) Apr 63 16 4 6 58mm 305gr
19 R 100mm f/3.5 (II) Apr 63 22 4 5 40mm 210gr
20 R 55-135mm f/3.5 Dec 63 22 10 15 58mm 790gr

 

The "R" Series Lenses by Aperture

 

 No. Name Released Min. f/ Blades Groups Elements Filter Weight
1 R 35mm f/2.5 Aug 60 16 6 5 7 58mm 317gr
2 R 50mm f/1.8 (I) May 59 16 4 6 58mm 295gr
3 R 50mm f/1.8 (II) Aug 60 16 4 6 58mm 305gr
4  R 50mm f/1.8 (III) Apr 63 16 4 6 58mm 305gr
5  R 55-135mm f/3.5 Dec 63 22 10 15 58mm 790gr
6  58mm f/1.2 Feb 62 16 8 5 7 58mm 432gr
7  R 85mm f/1.9 Jan 60 22 4 6 48mm 355gr
8  R 85mm f/1.8 Oct 61 16 8 4 5 58mm 470gr
9  R 100mm f/3.5 (I) May 61 22 4 5 40mm 210gr
10 R 100mm f/3.5 (II) Apr 63 22 4 5 40mm 210gr
11  R 100mm f/2 Sep 59 16 6 4 6 58mm 515gr
12  R 135mm f/2.5 Feb 60 16 6 4 6 58mm 630gr
13  R 135mm f/3.5 (I) May 59 22 10 3 4 48mm 370gr
14  R 200mm f/3.5 May 59 22 8 5 7 58mm 670gr
15  R 300mm f/4 Jan 60 22 4 5 48mm 1200gr
16  R 400mm f/4.5 Jan 60 22 4 5 48mm 1700gr
17  R 600mm f/5.6 Jan 60 32 1 2 48mm 2100gr
18  R 800mm f/8 Jan 60 32 1 2 48mm 1900gr
19  R 1000mm f/11 Jan 60 32 1 2 48mm 1800gr
20  TV 2000mm f/11 Sep 60 0 4 7 48mm 10,620

 

My “R” Series Lenses
L38

R 35mm f/2.5

the “R” series wide angle lens
L39

R 50mm f/1.8 I

the first of a 50mm classic

Canon LogoThis page is not a review of Canon equipment but rather a record of items in my Canon collection. I have no connection with Canon and receive no remuneration nor benefit for this work. Also, I have no rights to any Canon trademarks and they appear here through Canon’s kind indulgence.