Canon Pellix
Encyclopedia
In the mid 1960s through the lens exposure metering (TTL)
was the new technology entering the SLR camera market. The Pellix was Canon's answer to that challenge. This technology was first successfully realised in a 35mm SLR camera in the remarkable Tokyo Kogaku KK
Topcon RE-Super
, launched in 1963, but followed by the Pentax Spotmatic
a year later. Unlike the RE Super, the Pellix and the Spotmatic TTL exposure meter relies on stopping down the lens to measure the light, making the finder image dimmer. In October 2010, the Sony Corporation launched the Sony Alpha SLT-a55
based on the pellicle mirror
principle, but now called the Translucent Mirror technology, enabling continuous phase detection autofocus during multiple exposure
and movie
recording. However, since viewing through the camera is entirely based on the signal from the image sensor
rather than by way of a reflex mirror
, this camera is by definition not a single lens reflex camera, hence the SLT (single lens translucent) terminology.
range and launched the Canon FX
with the FL lens mount
. It has a built in CdS
exposure meter with a circular window on the right-hand camera front. The Canon FP
without exposure meter was added later the same year. The cameras were well built, but the metering technology was several years behind the Minolta SR-7 which pioneered that technology in 1962. Then just half a year later, in the spring of 1965 Canon surprised the camera community with the remarkable Pellix. The new camera featured the much-expected TTL exposure metering facility, albeit employing the stop-down metering method.
However, what makes the Pellix special, is that the TTL
metering is accomplished using a stationary semitransparent pellicle reflex mirror
instead of the traditional moving SLR mirror and placing a CdS meter cell
behind it for the TTL exposure measurement. The cell, attached to an arm is swung up in front of the film gate by pushing the stop down lever on the right-hand camera front, reading the light projected from the camera lens after passing through the semitransparent mirror. Very few alternative locations inside the camera were available for picking up light rays from the camera lens. The Topcon RE Super has its meter cell placed directly behind the reflex mirror into which a pattern of slits are cut to let the light though, while the Spotmatic has a pair of cells located either side of the finder window reading light off the focusing screen.
The stop-down lever at the left-hand camera front also operates the self-timer. Pushing the lever towards the lens activates the stop down match-needle meter, while pulling in the opposite direction winds the timer. As with the Canon FX and FP, the camera back is opened turning a key at the base. The film speed is set lifting and turning the rim of the shutter speed dial. The camera is designed for the obsolete 1.35 volt mercury battery, which fortunately may be directly replaced by a similar 1.4 volt hearing aid battery, it is usable for about a year after activation whether used or not. The battery compartment is at the left-hand edge of the camera, next to the rewind knob. The Pellix was replaced by the improved Canon Pellix QL first marketed in March 1966. Improvements included the addition of a quick film loading mechanism and contacts in the base of the battery compartment for a separately available electronic booster for the internal exposure meter.
The object of this arrangement - apart from accomplishing TTL metering, is for a simpler construction, a less noisy operation, and to get rid of the finder blackout during exposure. That is a favourable proposition, but the design has its flaws; the obvious one being loss of light, about one half stop (f/1.2) in the exposure through the semitransparent mirror, and about one and three-fourth stop (f/1.7) dimmer finder compared to using a fully reflecting mirror. A more serious problem however, is that the image forming light rays has to pass through the stationary pellicle mirror - in itself an obstruction, but over time the mirror surfaces also become soiled; it scatters the light and therefore degrades the projected image that forms the image on the film. If this occurs, or the fragile mirror is damaged in any way it has to be replaced.
It is true the finder does not go black during exposure, but at small lens apertures, the eye has no time to adjust to the dark finder. The operating noise from the Pellix is surprisingly similar to that of the Canon FX using a moving reflex mirror. Canon made two fast lenses, the FL 50mm 1:1.4 and the FL 58mm 1:1.2, in order to compensate for the light loss, but fast lenses might increase the risk of the sun burning holes in the shutter curtain not being protected by a solid mirror; a fact anticipated and solved by providing the Pellix with a metal shutter curtain. Another obstacle is the risk of light finding its way into the camera by way of the finder window during exposure, since there is no mirror to block the path in its up-position. This was also anticipated, and a finder blind is provided which is operated by turning the ring under the rewind knob, especially useful when leaving the camera on a stand. The Meter circuit is susceptible to breakage due to the CdS meter arm being moved into position behind the pellicle mirror during exposure reading. Two special lenses were made available for the Canon Pellix, utilising the fact the camera has a stationary mirror that will not hit the lens' rear element; the FLP 19mm 1:3.5 and the FLP 38mm 1:2.8. The FLP code shows that these lenses are for the Pellix camera.
Through-the-lens metering
Through-the-lens metering is a photographic term describing a feature of cameras capable of measuring light levels in a scene through their taking lenses, as opposed to a separate metering window...
was the new technology entering the SLR camera market. The Pellix was Canon's answer to that challenge. This technology was first successfully realised in a 35mm SLR camera in the remarkable Tokyo Kogaku KK
Topcon
Topcon is a Japanese manufacturer of optical equipment for ophthalmology and surveying. Their headquarters are in Itabashi, Tokyo. They are affiliated with Toshiba, which holds 40% of Topcon's stock.-History of Topcon:...
Topcon RE-Super
Topcon RE-Super
Tokyo Kogaku KK launched their first 35mm SLR camera in 1957, about two years before the Nikon F and the Canonflex. This was the Topcon R that acquired the bayonet lens mount from the Exakta Varex camera from Ihagee in Dresden, successor to the Kine Exakta of 1936...
, launched in 1963, but followed by the Pentax Spotmatic
Pentax Spotmatic
The Pentax Spotmatic is a range of 35mm single-lens reflex cameras manufactured by the Asahi Optical Co. Ltd., later known as Pentax Corporation, between 1964 and 1976. The original 1964 Spotmatic was one of the first SLRs to offer a through-the-lens exposure metering system, initially using...
a year later. Unlike the RE Super, the Pellix and the Spotmatic TTL exposure meter relies on stopping down the lens to measure the light, making the finder image dimmer. In October 2010, the Sony Corporation launched the Sony Alpha SLT-a55
Sony Alpha 55
The Sony α55 is a midrange-level SLT camera, released in August 2010....
based on the pellicle mirror
Pellicle mirror
right|thumb|The pellicle mirror of the [[Canon EOS RT]]A pellicle mirror is an ultra-thin, ultra-lightweight semi-transparent mirror employed in the light path of an optical instrument, splitting the light beam into two separate beams, both of reduced light intensity...
principle, but now called the Translucent Mirror technology, enabling continuous phase detection autofocus during multiple exposure
Exposure
-Entertainment:* Exposure , the practice of revealing the secrets of magic to non-magicians* Exposure , a short film anthology series on Sci-Fi Channel from 2000–2002* Exposure , a current affairs strand on ITV in 2011...
and movie
Film
A film, also called a movie or motion picture, is a series of still or moving images. It is produced by recording photographic images with cameras, or by creating images using animation techniques or visual effects...
recording. However, since viewing through the camera is entirely based on the signal from the image sensor
Image sensor
An image sensor is a device that converts an optical image into an electronic signal. It is used mostly in digital cameras and other imaging devices...
rather than by way of a reflex mirror
Reflex finder
A reflex finder is a viewfinder system with a mirror placed behind a lens. The light passing through the lens is reflected by the mirror to a focusing screen, usually ground glass...
, this camera is by definition not a single lens reflex camera, hence the SLT (single lens translucent) terminology.
The First Canon with TTL
Canon's sudden switch from professionally oriented SLR cameras to advanced amateur cameras happened in March 1964 when they left the Canon CanonflexCanon Canonflex
The Canonflex is a Canon 35 mm film single-lens reflex camera introduced in May 1959. Its standard lens is the Canon Camera Co. Super-Canomatic R 50mm lens 1.8. The camera was in production for one year before it was replaced by the Canonflex R2000, adding a 1/2000 sec...
range and launched the Canon FX
Canon FX
The Canon FX is a 35 mm SLR manufactured by Canon Inc. of Japan and introduced in April 1964. It introduced the Canon FL lens mount, the successor to the Canon R....
with the FL lens mount
Canon FL
Canon FL refers to a lens mount standard for 35mm single-lens reflex cameras from Canon. It was introduced in April 1964 with the Canon FX camera, replacing the previous Canon R mount. It was in turn replaced in 1971 by the Canon FD lens mount...
. It has a built in CdS
Photoresistor
A photoresistor or light dependent resistor is a resistor whose resistance decreases with increasing incident light intensity. It can also be referred to as a photoconductor or CdS device, from "cadmium sulfide," which is the material from which the device is made and that actually exhibits the...
exposure meter with a circular window on the right-hand camera front. The Canon FP
Canon FP
The Canon FP is a 35 mm SLR manufactured by Canon Inc. of Japan and introduced in October 1964. It introduced the Canon FL lens mount, the successor to the Canon R....
without exposure meter was added later the same year. The cameras were well built, but the metering technology was several years behind the Minolta SR-7 which pioneered that technology in 1962. Then just half a year later, in the spring of 1965 Canon surprised the camera community with the remarkable Pellix. The new camera featured the much-expected TTL exposure metering facility, albeit employing the stop-down metering method.
However, what makes the Pellix special, is that the TTL
TTL
TTL may refer to:* Taiwan Tobacco and Liquor, a state-owned manufacturer of cigarettes and alcohol in Taiwan* Through-the-lens metering, a feature of cameras capable of measuring light levels in a scene through their lens...
metering is accomplished using a stationary semitransparent pellicle reflex mirror
Pellicle mirror
right|thumb|The pellicle mirror of the [[Canon EOS RT]]A pellicle mirror is an ultra-thin, ultra-lightweight semi-transparent mirror employed in the light path of an optical instrument, splitting the light beam into two separate beams, both of reduced light intensity...
instead of the traditional moving SLR mirror and placing a CdS meter cell
Cadmium sulfide
Cadmium sulfide is the inorganic compound with the formula CdS. Cadmium sulfide is a yellow solid. It occurs in nature with two different crystal structures as the rare minerals greenockite and hawleyite, but is more prevalent as an impurity substituent in the similarly structured zinc ores...
behind it for the TTL exposure measurement. The cell, attached to an arm is swung up in front of the film gate by pushing the stop down lever on the right-hand camera front, reading the light projected from the camera lens after passing through the semitransparent mirror. Very few alternative locations inside the camera were available for picking up light rays from the camera lens. The Topcon RE Super has its meter cell placed directly behind the reflex mirror into which a pattern of slits are cut to let the light though, while the Spotmatic has a pair of cells located either side of the finder window reading light off the focusing screen.
The stop-down lever at the left-hand camera front also operates the self-timer. Pushing the lever towards the lens activates the stop down match-needle meter, while pulling in the opposite direction winds the timer. As with the Canon FX and FP, the camera back is opened turning a key at the base. The film speed is set lifting and turning the rim of the shutter speed dial. The camera is designed for the obsolete 1.35 volt mercury battery, which fortunately may be directly replaced by a similar 1.4 volt hearing aid battery, it is usable for about a year after activation whether used or not. The battery compartment is at the left-hand edge of the camera, next to the rewind knob. The Pellix was replaced by the improved Canon Pellix QL first marketed in March 1966. Improvements included the addition of a quick film loading mechanism and contacts in the base of the battery compartment for a separately available electronic booster for the internal exposure meter.
The pellicle mirror
The semitransparent fixed mirror in the Pellix, for the first time successfuly used in a 35mm SLR camera, lets about two-thirds (66%) of the light from the lens pass directly through to the film, while the rest is reflected to the viewfinder.The object of this arrangement - apart from accomplishing TTL metering, is for a simpler construction, a less noisy operation, and to get rid of the finder blackout during exposure. That is a favourable proposition, but the design has its flaws; the obvious one being loss of light, about one half stop (f/1.2) in the exposure through the semitransparent mirror, and about one and three-fourth stop (f/1.7) dimmer finder compared to using a fully reflecting mirror. A more serious problem however, is that the image forming light rays has to pass through the stationary pellicle mirror - in itself an obstruction, but over time the mirror surfaces also become soiled; it scatters the light and therefore degrades the projected image that forms the image on the film. If this occurs, or the fragile mirror is damaged in any way it has to be replaced.
It is true the finder does not go black during exposure, but at small lens apertures, the eye has no time to adjust to the dark finder. The operating noise from the Pellix is surprisingly similar to that of the Canon FX using a moving reflex mirror. Canon made two fast lenses, the FL 50mm 1:1.4 and the FL 58mm 1:1.2, in order to compensate for the light loss, but fast lenses might increase the risk of the sun burning holes in the shutter curtain not being protected by a solid mirror; a fact anticipated and solved by providing the Pellix with a metal shutter curtain. Another obstacle is the risk of light finding its way into the camera by way of the finder window during exposure, since there is no mirror to block the path in its up-position. This was also anticipated, and a finder blind is provided which is operated by turning the ring under the rewind knob, especially useful when leaving the camera on a stand. The Meter circuit is susceptible to breakage due to the CdS meter arm being moved into position behind the pellicle mirror during exposure reading. Two special lenses were made available for the Canon Pellix, utilising the fact the camera has a stationary mirror that will not hit the lens' rear element; the FLP 19mm 1:3.5 and the FLP 38mm 1:2.8. The FLP code shows that these lenses are for the Pellix camera.