FD 35mm f2.0 with concave front element?

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From what I understand, this is the sharpest 35mm f2.0 Canon ever made. It was replaced in the breechlock mount with a convex front element lens, which I believe was an S.S.C., and apparently was not very good. Canon redesigned the lens for their new bayonet mounts and is a much better lens than the S.S.C. but not as good as the concave element lens. Does anyone know when the change over took place and is the lens availabe in an S.C. or S.S.C.? Also, the lens used a thorium rare earth element that supposedly produced a green cast. Any comments? I used to have this lens and I remember it as superb with no color casts, but it's been so long ago that I don't remember the coating. Thank you. Dennis

-- Dennis O. Larsen (larsenqs@vzavenue.net), March 04, 2002


According to Canon's museum website: http://www.canon.com/camera- museum/camera/lens the concave SSC lens was introduced in '73 and it's replacement came out in '76.

I don't have one but I recall hearing that the concave lens gave a yellow cast.


-- Duane k (dkucheran@creo.com), March 04, 2002.


My copy of "An Introduction To The Canon F-1" 11/75 printing shows the concave element 35/2 with a black filter ring and describes it as an SSC lens. I believe this lens was introduced with the F-1 in 1971 with single coating and chrome filter ring. I have seen examples of this lens in both versions. I'm guessing the convex element version may have debuted in late '75 or in 76 with the F-1n. I own this later version and have never found it's performance anything to comlain about, though I've read of people favoring the earlier version.


-- Bill Salati (wsalati@hotmail.com), March 05, 2002.

This is very interesting to me. I have an older, bayonet-mount Canon 35mm f 2.0 lens, with the silver ring. Mine was received with a black Hoya Super 55mm UV(O) filter. It does have a concave front element, and is marked "S.S.C." on the front. Mine does produce a photo with a different cast to it, but I did not see it as green. Now, as I look at a few photos, I'm not so sure. I'm going to have to shoot some comparison photos now. You've made me feel pretty good about having acquired this lens. Thanks for the infor

-- John Ratliff (cratliff@easystreet.com), March 07, 2002.

According to various literature sources, and (at least) a few posts on this very site a few years back, the FD 35mm 1:2.0 was introduced with the concave front element back in '71, along with the original introduction of many other FD lenses. It went through the change from chrome to black snout but remained pretty much unchanged until '73, when Canon began upgrading the FD series with lighter materials, SSC coating (and associated markings) and some new lenses.

The 35mm 1:2.0 also received the upgades (it became lighter, received the SSC coating - it had been SC until then - and also bore the red SSC marking) but it retained the concave front element until '76, when it the lens was re-engineered to use the convex front element and futher weight savings were achieved. It remained in this state until the new bayonet mount was introduced in '79; the optics were changed again at that point.

The really interesting thing about the concave lenses is Canon's use of thorium thoride in one or more of the interior elements. Thorium is a radioactive element and it's use was evidently just another one of Canon's experiments with exotic glass (think florite). It was intended, in laymen's terms, to improve performance...

And improve it it did: these concave 35mm lenses are highly renown for their sharpness, corner to corner, and high contrast (not only in the "sweet spot" of f/5.6 & f/8, but throughout). But the performance came at a price: the thorium imparts a yellowish (some say greenish) cast to the exposed film, and will not match up in color rendition to other FD lenses. Hell, sight through the lens unmounted: you'll see a decidedly yellowish tint.

I've read that Canon dropped the use of thorium in lenses due to the difficulty of handling the radioactive dust, prior to the manufacture of the glass. There is no danger the owner/user in the finished product, I'm sure!

As for the lens, I have an early one and it IS very, very sharp. While I understand that you can counteract some of the tint by using certain colored filters, I use the lens without filters and (mostly) in two definite situations: when I want to add a warm cast to the exposed film (fall afternoon effect, etc.) and for black & white. The thorium element acts something like a red/orange/yellow filter would with black & white film, and (subtly) seems to bring out even better contrast.

I don't use the lens that often, but when I do I am always pleased with the sharp, contrasty results. Just don't expect color consistency with your other FD lenses. I suggest you experiment a bit with it to see what its strengths (and limitations) are, but... I'd be surprised if you didn't learn to like it a lot.



-- Tim (duosonic@pacbell.net), March 09, 2002.

I too owned one of these concave element breech mount 35mm f2 SSC's. I must say I enjoyed the photos it took but it was not a focal length I used often. Then I discovered this strange yellow cast. I couldn't avoid it with different films and then I realized I could see the yellow cast just looking through the lens. Sorry, but it drove me nuts! I knew it was rated highly at the time but with not using it often I traded it in to help get my wife a camera. It was last year that I first saw a reference to the glass and the yellow cast on the internet. John Crowe

-- John Crowe (jenandjohn@sprint.ca), March 09, 2002.

After my above posting, I took most of a roll of ASA 100 print film with my 35mm f2.0 lens, and guess what--no yellow cast on the prints. I think that the automatic printing machines in today's shops will get rid of the green/yellow cast on color print film. And it is a very, very sharp l

-- John Ratliff (cratliff@easystreet.com), March 16, 2002.

Anyone know of any other radioactive Canon lenses?


-- adam g. lang (aglang@hotmail.com), March 20, 2002.

I have another famous "radioactive" lens: the 55mm f:1.2 Aspherical The yellow cast has increased with time. Still acceptable for colour printing but not for slide projection. Incredible performance near wide open but this lens is too bulky to use it as a standard normal lens around f:5.6 (compared to the 50mm f:1.8 and 1.4), Marco

-- Marco (marc.bingen@swing.be), March 21, 2002.

Interesting! That is the first I had heard that the 55/1.2 Aspherical is radioactive. DO you know if the later new FD 50/1.2L is?

-- adam g. lang (aglang@hotmail.com), March 21, 2002.

Bananas are radioactive because of their potassium. Coleman lantern wicks are radioactive. So are some beaches in Hawaii. And (ever so slightly) humans. Types of radioactivity vary. Are you interested in Alpha particles (helium nuclei), Betas (electrons), Gamma rays? How many Roentgens above background? What is the point of this inquiry into the radioactivity of glass mixed with rare earths?

-- Robert Segal (robertsegal@juno.com), March 21, 2002.

Robert- It is silly, but women are often irrational about this sort of thing, if you get my drift....

-- adam g. lang (aglang@hotmail.com), March 21, 2002.

I'm not so interested in the radioactivity (it's probably well contained within the lens itself in any event) as I am in the optical purity of this glass. Any comments on that?


-- John C. Ratliff (cratliff@easystreet.com), March 24, 2002.

Does anyone have a concave FD 35 f2 for sale? I am curious to play with one and the yellow "warm" tones just might complement the dirt colours here in Australia? Drop me a line. I shoot a lot of slides and these would be a dead loss for this lens but some kinds of prints might be OK.

-- Alexander A Deme (aad123456@yahoo.com.au), April 24, 2002.

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