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- Early Canon FD Lens Instructions
- Why you Can't Use an FD Lens on an EOS Camera
- Early Zooms
- The FL 55-135mm f/3.5 Does Exist!
- Canon Spectra and Super Spectra Coating
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Early Canon FD Lens Instructions
Lens instruction manual from 1979, lists all FD lenses (breech lock, with rotating silver ring to lock) but no New FD lenses (breech lock, entire lens mounts to lock).
- Canon FD Lens Instructions; scanned from original paper copy provided by F. Svoboda of Hutchinson, MN
Problems of Mounting FD Lenses on EOS Cameras
The Problem
Canon FD mount lenses cannot be used directly on current production EOS cameras that use the EF lens mount. The FD and EF lens mounts are physically very different, the FD mount being a breech-lock in which a ring on the lens, or the entire lens outer body of the New FD mount lenses, clamped onto flanges on a cylindrical protrusion from the camera body, while the EF mount is a bayonet mount, in which a protrusion from the rear of the lens has flanges that clamp onto surfaces inside the camera body.
The flange-to-image-plane distance, called the flange focal distance, is 42 mm for the FD mount but 44 mm for the EF mount. Thus an FD mount lens held against an EOS body by any means would be 2 mm too far from the film plane to focus to infinity. These Wikipedia links document the problem:
http://en.wikipedia.org/wiki/FD_mount#Using_FD_lenses_on_other_mounts
Aftermarket EF Lens to FD Camera Converters
Inexpensive aftermarket EF-to-FD mount converters are 1.3X teleconverters and provide poor image quality, cover the APS-C format (22.2mm by 14.8mm); the APS-C sensor size is used in most digital SLR's that sell for less than $2,000. The aftermarket EF-to-FD converters I have seen advertised do not cover the full 35mm frame (36mm by 24mm). Some of them project back into the camera and may interfere with the mirror of full-frame cameras.
Many Canon FD mount lenses cannot be used with these converters because the converters have optics that project into the rear of the lens, and only longer telephoto lenses have a cavity at the rear of the lens mount that allows them to be mounted on these converters.
Some recent aftermarket EF to FD mount converters will mount most FD lenses, but they are 1.4X or longer teleconverters, and again cover only the APS-C image size with degraded image quality. This pretty much eliminates all utility of wide angle lenses and the 7.5mm fish-eye (which I found out will not mount on one such converter that I bought), but may be of interest for fast lenses and zoom lenses. I do not guarantee compatibility or image quality of any lens that I list on eBay with any aftermarket converter, or for use in any configuration not recommended by Canon.
EF to FD Converters Without Optics
A lens mount converter to mount FD lenses on an EF-mount camera that do not have optics amount to an extension tube. Lenses will not focus to infinity when mounted this way and can only be used for close-up or macro work.
Splice an EF Mount on an FD Lens?
Qualified camera and lens repair facilities may (or may not) be found to graft an EF mount onto an FD lens, which has 2 mm less mount-to-focal-plane distance than the EF mount but about that much room in the FD mount itself, but this cannot be done for all lenses and is quite expensive; I have seen documentation of this surgery only for very expensive lenses such as the FD 50mm f/1.2L. If I had something like an FD 300mm f/2.8 Fluorite or L, I would consider it.
Canon's EF to FD Adapter
The excellent Canon EF-to-FD mount converter that was briefly available about 1995 is Canon part number C54-2131. It was available only through Canon Professional Services for about $240. Used ones have been spotted for $1000 but I would contact Canon Professional Services before I bought one; they just might locate one for the right customer. In any case they too are 1.26X teleconverters, include optics that project into the lens and will mount only certain telephoto New FD Mount lenses introduced after June 1979 ("FD lenses with a chrome mount ring cannot be used" from the data sheet!), and the effective f-stop at the camera cannot exceed f/3.5 no matter how fast the FD lens because of the 2/3 f-stop reduction and the f/2 aperture of the converter optics. I believe that it covered the full frame because it was designed for the EOS-1, a film camera.
There is a page with a photo of the Canon converter and other material on it. This was provided to the linked web site some time ago by Ian Hobday, who was living in Osaka, Japan at the time. Links to his home page and eBay store from that page are dead. The page:
Click Here (long link)
The archive.com wayback archive shows that Ian Hobday's web page and domain, hobday.net, was active from 2002 to 2008, with a blank main page but photos posted in a subpage from 2004 to 2008:
Most or all of the photos seem to date to 2004. Ian Hobday is still listed on LinkedIn as an IS professional in Osaka, Japan.
The Ultimate Solution
Sony E-Mount
In 2010, Sony introduced a compact mirrorless line of interchangeable cameras using a new lens mount, the E-Mount. Some of these cameras are full frame, and the flange focal distance is only 18mm, same as the Canon M series compact mirrorless cameras. But, the Canon M series does not yet include a full frame sensor. The Sony E-Mount cameras that have a full-frame sensor are designated as "alpha series" with a single digit, as "Sony α7 III". Adapters that allow focus to infinity are available from Fotodiox, Metabones, and others; these are available from B&H Photo, Amazon, and other online and brick-and-mortar discount outlets.
Micro Four Thirds
FD mount lenses can be used on micro four-thirds cameras using adapters that do not have optics and yet focus to infinity when so used. However, the micro four-thirds focal plane is just 17.3 mm by 13 mm, which is smaller than the APS-C (about 23 mm by 15 mm, varies slightly with manufacturer) and is far smaller than the full-frame image size of 36 mm by 24 mm that all FD lenses are designed for.
Leica M9 and Later
FD mount lenses can be used without degradation with full-frame imaging on at least one digital camera, the Leica M9, the current-production Leica digital rangefinder camera, which uses a Kodak full-frame CCD sensor that produces 18.5 megapixel photographs. Albeit quite pricey (possibly more pricey than an EOS-1Ds and a working suite of L-series EF mount lenses!), this is the only really acceptable option for use of FD lenses on a digital camera. But, if you have a Leica M9 and would like to take full advantage of Canon FD mount lenses, then, yes, you can.
Novoflex makes the adapters for FD to micro four thirds and Leica M mount, as well as some interesting other adapters; their web page is (new tab or window):
The Leica page on the M9 is
Flange Focal Distances of Various Lens Mounts
Wikipedia has an article on lens mounts in general that includes a table of data on all lens mounts in common use from about 1950 through 2010, the last column of which gives the flange focal distance. This is important because simple adapters, without optics, for FD lenses to go on cameras that will allow focusing to infinity are possible only for cameras using a mount with a smaller flange focal distance. See the Wikipedia pages:
Sizes of Focal Planes
The Wikipedia article on the micro four-thirds system has an excellent graphic showing the differences in image size for various digital camera systems:
We reproduce that graphic here:
Early Zoom Lenses for SLR's
Here I am discussing true zooms for SLR's, e.g. mass produced and retailed zoom lenses that retain their focus when their focal length is changed. These opinions apply to 35mm photography equipment in general, not just Canon. I consider "varifocal" lenses that needed to be refocused when the focal length was changed to be mostly irrelevant to the general public, albeit of historic interest as the initial ground-breakers in the transition of zoom capability from movie and commercial optics to 35mm photography for consumers.
Until the middle 1970's lens design was an art practiced by an elite few by means of endless hard work, and zoom lenses presented a particular challenge when excellence of image quality was an inflexible requirement. Even today the best image quality is produced by hand polishing final lens assemblies on an optical test bench before final coating and assembly, and this expensive highly skilled labor-intensive step drives the cost of high quality lenses, particularly zoom lenses.
This Wikipedia article is more attuned to school research projects than optical research and history but it does give a good, if spotty perspective of the history and technology of zoom lenses (new tab or window):
Canon was very particular about the performance of their zoom lenses from the very beginning, which was late 1960's for mass produced zoom lenses available to consumers for use on 35mm SLR's. No Canon zoom lens was released with poor performance at any focal length just to fill a market niche with a Canon product, regardless of other offerings of the time. The result was that Canon and a few others introduced zoom lenses slowly, until computer-designed lenses became the norm in the late 1980s. There were no zoom R mount lenses, only three zoom FL lenses – the first appearing in 1964, six zoom FD lenses, but 23 zoom New FD lenses and a vast number of zoom EF lenses. Every one can be counted upon for good image quality at every focal length. Some of the more expensive are truly excellent, corner to corner, at all available focal lengths.
The FL 55-135mm f/3.5 Does Exist Out There!
There is one very early Canon zoom lens that I have never seen, but someone has contacted me that has two and pointed me to one available on eBay that has a couple of pictures. It's a two-touch, and looks a little like a miniature FL 85-300mm f/5. The zoom range, f-stop, and apparent price range of around $400 (1964 dollars) with Canon's traditional excellent image quality throughout the zoom range defines an expensive but yet a good value for leading-edge performance. The FL 55-135mm f/3.5 of March 1964 was an FL mount update of Canon's first commercial zoom lens for 35mm cameras, The R55-135mm f/3.5 that was released for the R mount in December 1963. Canon did introduce a zoom movie camera in 1959, the Reflex Zoom 8.
This lens exists out there in very small quantities and the Canon Camera Museum lists it, and I've heard from someone who has two of them. There was an FD version that was mentioned later in the trade magazines and I've seen a photo of it, but it's not listed in the Canon Camera Museum Lens Hall, so, apparently, it was never released commercially.
Canon FD Lens Coatings: Spectra, Super Spectra, and Not Stated
Spectra Coating is Canon's trade mark for their proprietary antireflection lens coating technique. The thickness of coating on each lens surface is varied to maximize transmission and minimize flare across the visible spectrum. The mechanism is a complex process in which reflected light of different wavelengths follow separate paths, but all are reflected from one lens surface to exit the lens or be absorbed by the barrel without further reflections, thus achieving flare performance comparable to other manufacturer's multicoating techniques with higher light transmission than would be achieved with multicoating the same lens. You can see the differences in wavelengths of maximum reflection and transmission on each surface in the coloration of the reflections of the twin-lite flash used in the close-ups of any Canon SLR lens; see the photographs of the front and rear of each lens that I put up for sale on eBay. Other manufacturers use some generally less sophisticated coating variation for the same reason; I have seen lens coating listed on some camera equipment sales web sites as "amber and magenta" for example.
Canon apparently used Spectra Coating for some years even prior to their SLR lenses, but in the early 1970's some manufacturers such as Pentax suddenly offered multi-coating, or multi-layer lens coatings, prominently advertising it as providing superior flare performance to single coated lenses. Canon began advertising their technique as Spectra Coating, and lenses introduced in the 1970's between about 1973 and 1979 were often labeled "S.C." or "S.S.C." for Super Spectra Coating, which was multiple lens coats with the surface-to-surface variation that is used in Spectra Coating. Faster lenses and most zoom lenses with more than about six groups of elements usually have S.S.C., but many simpler lenses do not benefit from S.S.C. over S.C. and were updated through the 1970s with the designation S.C. This is an unusual advertising and product labeling strategy, advertising single coated lenses where that works best – and contradicting competitors' assertions that multicoating is always better.
FL and FD lenses introduced prior to 1973, and all lenses introduced after the New FD mount lenses were introduced in 1979 do not have the designations S.C. or S.S.C., although of course these techniques were used on these lenses. Current production EF lenses continue to use evolved sophisticated surface-to-surface lens-specific variable coating techniques. You can see it by looking at variations in the color of highlights on the internal lens surfaces. I always include photographs of the front and rear of the lenses that I post on eBay and use a twin-lite flash, so that reflections from the flash heads show the differences in coatings on the various internal lens surfaces.