Canon Pellix

Canon Pellix

Ivor Matanle traces the history of the worldfirst SLR with fixed pellicle mirror

THE RECENT announcement of the Alpha 37 as an addition to Sony s range of single-lens translucent (SLT) cameras with  non-flipping  pellicle mirrors brought to mind the furore Canon started back in 1965 with the Canon Pellix, :he world s first SLR with a stationary pellicle mirror. The idea then, as now, was great. Not needing a mechanism to raise and cushion the mirror when the shutter was fired reduced the complexity, weight and potentially the manufacturing costs of the Canon Pellix

when compared with its  normally designed  contemporary, the Canon FT. However, the lower manufacturing cost was never realised because of quality assurance issues. The considerable reduction of vibration when the shutter was fired, without the mass of a mirror crashing around, was a substantial contributor to reduced camera shake and thereby to the improved quality of handheld shots at mid-range shutter speeds.

However, just as picture quality was improved by the lack of vibration, so it

was reduced by the fact that the image reached the film through the pellicle mirror. Brilliant as it was, Canon technology could not totally overcome the effect on quality brought about by passing the image from the lens through the mirror to the film.

There was also a major impact on viewfinder brightness. The light received by the pellicle mirror from the lens was shared, so that roughly two thirds was passed through the mirror to the film (or shutter, when the shutter was closed) and the remaining one third was directed to the viewfinder.

In the Canon FT, which was contemporary with the Pellix and equipped with a conventional moving SLR mirror, all the light from the lens, apart from a small degree of loss due to reflection, was passed to tne viewfinder optics and the bcusing screen.

Canon s response was to recommend that the standard lens for the Pellix should be the 50mm f/1.4 Canon FL optic, which had an aperture less than 1 stop greater than that of the 50mm f/1.8 Canon FL, which was normally sold with the Canon FT. Most photographers who used a Pellix for professional work reckoned that it really required the much more expensive 58mm f/1.2 Canon FL lens to provide adequate viewfinder brightness, and this became the professional standard lens on the Pellix.

Another significant practical advantage o pellicle mirrors is that the viewfinder image remains constant, without the momentary loss of image caused when a normal mirror is moved out of the way during each exposure. Anyone who has photographed racing cars, horse racing or athletes, especially when using a motordrive, will know that it is constantly necessary to watc for changes-collisions, falls, exceptional developments-to ensure that you get the picture that really matters. The ability of the pellicle mirror to provide uninterrupted viewing and to do it throughout a rapid sequence of exposures led to its use by Canon in the later high-speed versions

of the Canon FI and New FI, and to its adoption by Nikon for the high-speed versions of the Nikon F2 and F3. Canon continued with the use of pellicle mirrors into the age of autofocus with the EOS RT and EOS-1 N RS professional models. When moving-mirror design acquired the ability to allow rapid sequences of exposures, the pellicle mirror was quietly dropped.

PELLIX QL

In 1966, the Pellix QL, a modified version of the Pellix, was announced. It was called QL because, in common with the Canon FT, it had been equipped with Canon s excellent  quick load  system, which made it unnecessary to thread the film into the take-up spool. You simply laid the film across the shutter area so that the perforatons engaged with the drive sprockets, and closed the camera back, in the process closing the quick-load mechanism over the

Canon Pellix

film. I found this loading system excellent during the years when I was using Canon manually loaded film cameras.

The new Pellix was prominently marked with the  QL  logo and continued, unlike any other Canon model, to have the model s name, Pellix, engraved on the front of the prism, rather than the brand name, Canon.

TTL METERING

In 1965, when the first version of the Pellix was announced, Canon was still a year away from being able to announce the launch of the company s first conventional SLR with through-the-lens (TTL) exposure measurement, the Canon FT. Nonetheless, the major market success of the Pentax Spotmatic of 1964 and of the remarkable 1963 announcement of the Topcon RE Super with full-aperture TTL metering had demonstrated that TTL metering was essential if the Pellix were to be successful.

So the Canon designers came up with a meter that had its CdS cell on an arm. This was swung down into the light path behind the nirror when the diaphragm stop-down lever on the right-hand side of the mirror box was operated, and swung back out of the way when exposure had been set and the diaphragm returned to full aperture. This was Canon s first through-the-lens exposure-measurement system, operating a slender needle on the right-hand side of the focusing screen, which was centred onto an index circle either by altenng the lens aperture (with the lens stopped down

to the taking aperture) or by changing the shutter speed.

The pellicle mirror itself, as fitted to the Pellix models, was a remarkably thir (.200mm) piece of Mylar foil, on which the semi-reflective surface was vapour deposited. The precise positioning of such a delicate membrane was near to the limit of available manufacturing technology in the mid-1960s, and many of the reported quality-assurance problems arose from ensuring precise positioning.

FL AND FLP LENSES

All Canon FL SLR lenses from 1965-1966 had the Canon breechlock mount, which located the lens to a bayonet on the body and locked it via a revolving metal collar. A total of 25 FL lens types, including three zooms, were marketed. As well as having the letters as part of the lens description around the front bezel, f"L lenses can be recognised by having one rear coupling pin for the diaphragm on the rear face of the lens where it matches to the camera.

Most of the Canon FL lenses can be used on the Pellix models, including the very effective 50mm f/3.5 Macro. The Canon Pellix, with stationary mirror, offered lens-design opportunities denied in a normal SLR because of the usual necessity of keeping the rear of the lens out of the way of the moving mirror. Canon took advantage of this by making two special wideangle lenses, coded FLP and clearly marked on the breechlock ring Pellix Only’. These were the 19mm f/3.5 FLP retrofocus, which is rare, and the 38mm f/2.8 FLP. Canon literature shows that the 38mm FLP is a Tessar-type lens, with four groups arranged as three elements. It is an extremely compact pancake-style lens, with the mount serving as a built-in lens hood. Interestingly, Canon engineered the diaphragm coupling pin of the FLP lenses so they will not mount on a conventional Canon SLR.

ACCESSORIES

There was a vast range of accessories for the Canon range of the mid-1960s and virtually all can be used with the Pellix. Close-up accessories included the Canon FL bellows, extension tubes and close-up lenses, with filters and lens hoods galore. AP

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