Guides · 12 min
Canon FL vs FD vs New FD: Differences and Compatibility
Identify Canon FL, FD and New FD lenses, understand their metering differences, and check compatibility across classic Canon film cameras.
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Guides · 12 min
Identify Canon FL, FD and New FD lenses, understand their metering differences, and check compatibility across classic Canon film cameras.
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Canon produced several interchangeable-lens systems before introducing the EOS mount in 1987. Among the most important for collectors of manual-focus 35mm cameras are FL, FD and New FD.
These three lens generations share closely related mechanical mounting systems, but they do not provide identical camera functions.
The essential difference is that FL lenses generally require stopped-down metering, while FD and New FD lenses support full-aperture metering and compatible automatic-exposure systems. New FD lenses also introduced a different locking mechanism that made changing lenses more convenient.
Understanding these distinctions is particularly important when assembling a Canon system from equipment manufactured across several decades.
The Canon FL system appeared in 1964, replacing the earlier R mount used on Canonflex cameras.
FL lenses incorporated automatic diaphragm operation. This allowed photographers to compose and focus at maximum aperture before the camera stopped the diaphragm down for exposure.
However, FL lenses did not communicate their selected aperture to the camera through the later FD coupling mechanism.
On compatible metered cameras, exposure measurements therefore required the lens to be stopped down to its working aperture.
The Canon Pellix, introduced in 1965, was an important FL-mount camera equipped with through-the-lens metering.
Other FL bodies included the Canon FX, Canon FP and FT QL.
Although these cameras shared much of their mechanical architecture with later Canon cameras, their exposure-control capabilities were different.
The FD system arrived in 1971 alongside the professional Canon F-1 and the more accessible FTb.
Its major innovation was improved mechanical communication between lens and camera.
FD lenses incorporated additional aperture-coupling mechanisms that allowed compatible camera bodies to measure exposure with the diaphragm fully open.
The camera could determine the selected aperture without requiring the photographer to darken the viewfinder for every reading.
This system also made more advanced automatic exposure possible.
The breech-lock FD mount retained a rotating locking ring.
When attaching a breech-lock FD lens, the photographer positioned the lens against the camera and rotated the locking ring to secure it.
The main lens barrel remained stationary during this operation.
Canon introduced the New FD generation in 1979.
The principal mechanical change was the replacement of the externally operated breech-lock ring with a more convenient mounting mechanism.
New FD lenses attach with a twisting motion similar to a conventional bayonet lens.
However, their mating surfaces remain stationary as the outer lens assembly turns.
Importantly, New FD did not introduce a fundamentally incompatible lens system.
Breech-lock FD and New FD lenses are designed for the same group of camera bodies and retain the essential exposure-coupling functions.
Canon continued developing the New FD range until the transition to the EOS system and its electronic lens mount.
A Canon lens can often be identified from its name ring, mounting mechanism and rear coupling levers.
Most Canon FL lenses display the letters FL on their front name ring.
They use a rotating breech-lock ring at the rear.
Their aperture coupling is simpler than the later FD system because they lack the additional mechanism required to communicate aperture settings for full-aperture metering.
Some FL lenses also have a distinctive manual/automatic diaphragm control ring.
The exact arrangement varies between generations.
For example, Canon manufactured several versions of its FL 50mm f/1.4, including the redesigned FL 50mm f/1.4 II introduced in 1968.
Early FD lenses generally carry the letters FD and feature an external rotating locking ring.
Many early examples have a silver-coloured front section, informally known as the chrome nose.
Later versions adopted predominantly black finishes.
These cosmetic changes do not necessarily correspond to a new optical formula.
The aperture ring may also display an automatic-exposure setting marked A or, on some earlier versions, a green circular mark.
Early FD lenses contain additional mechanical coupling components absent from conventional FL lenses.
These components communicate aperture information to compatible cameras. The Canon FD 24mm f/2.8 S.S.C. is one documented example of this generation.
New FD lenses are readily distinguishable.
They lack the traditional externally operated breech-lock ring.
Instead, a release button near the rear of the lens disengages the locking mechanism.
The photographer rotates the lens assembly to mount or remove it.
New FD lenses also generally have a smaller profile, although dimensions vary considerably by model.
A collector should identify the mounting mechanism rather than relying exclusively on the colour or typography of the name ring.
| Characteristic | Canon FL | Canon FD | Canon New FD |
|---|---|---|---|
| Introduction | 1964 | 1971 | 1979 |
| Basic mounting interface | Breech-lock | Breech-lock | Twist-lock bayonet-style mechanism |
| Main lens locking method | Rotating ring | Rotating ring | Rotating lens assembly |
| Automatic diaphragm | Yes | Yes | Yes |
| Full-aperture metering coupling | No | Yes | Yes |
| Compatible automatic exposure | No FD-style AE coupling | Yes, body-dependent | Yes, body-dependent |
| Manual focus | Yes | Yes | Yes |
| Native compatibility with EOS cameras | No | No | No |
All three generations were designed primarily for the 24 × 36mm format.
These distinctions concern the conventional lens lines. Some specialized lenses and accessories have additional operating restrictions.
Yes, many Canon FL lenses can be mounted on FD camera bodies.
This backwards compatibility was an important feature of Canon's transition to the newer system.
However, mechanical compatibility must be distinguished from exposure compatibility.
An FL lens does not possess the same aperture-coupling mechanisms as an FD lens.
Consequently, using it on an FD camera generally requires stopped-down metering.
The Canon AE-1 normally provides shutter-priority automatic exposure with compatible FD lenses.
When an FD lens's aperture ring is placed in its automatic position, the camera can select the appropriate diaphragm opening.
An FL lens does not provide this coupling.
Instead, the photographer must select an aperture and use the camera's stopped-down metering procedure.
The exposure is then adjusted manually.
Canon explicitly describes this distinction in the AE-1 instruction manual.
The procedure should be followed carefully because the position of the stopped-down lever affects the camera's metering behaviour.
Purpose-built or early lenses may introduce further restrictions, so physical mounting alone should not be considered proof of full compatibility.
Yes.
The New FD mounting mechanism was designed to remain compatible with the established FD camera system.
A New FD lens can therefore be used on an early Canon F-1, FTb, AE-1 or other compatible FD body.
Similarly, a breech-lock FD lens can be used on later cameras such as the Canon AE-1 Program.
The method of attaching the lens differs, but the essential mechanical connections remain compatible.
This is particularly useful for photographers who want to combine an early mechanical body with later, smaller lenses.
However, certain viewfinder displays and specialized camera functions may vary between lens generations.
For example, lens aperture-ring placement can affect the direct optical display of aperture values on particular Canon New F-1 finder configurations.
These differences do not generally prevent normal photography.
Not automatically.
The introduction of New FD involved improvements in handling, dimensions and manufacturing, but optical changes must be evaluated individually.
A useful example is the Canon 50mm f/1.4.
Canon introduced the first FD 50mm f/1.4 in March 1971.
According to Canon's historical specifications, it uses 7 elements in 6 groups.
It has a minimum focusing distance of 0.45 metres, a 55mm filter thread and a weight of approximately 370 grams.
The New FD 50mm f/1.4 appeared in June 1979.
It also uses 7 elements in 6 groups, but Canon describes improvements intended to increase compactness and contrast.
The New FD model weighs approximately 235 grams and uses a 52mm filter thread.
Both focus down to 0.45 metres.
This comparison illustrates how lenses with identical focal lengths and maximum apertures may nevertheless differ significantly in construction and handling.
It also demonstrates why collectors should identify the exact generation rather than recording every Canon FD 50mm f/1.4 as a single undifferentiated item.
Canon used several coating designations during the FD period.
S.C. stands for Spectra Coating.
S.S.C. stands for Super Spectra Coating.
These coatings were developed to reduce unwanted reflections and improve contrast.
On many breech-lock FD lenses, the coating designation is engraved directly onto the front name ring.
However, Canon generally stopped displaying these designations on New FD lenses.
Therefore, the absence of S.C. or S.S.C. lettering does not mean that a New FD lens lacks sophisticated coatings.
The coating specification and optical construction should be checked for the exact model rather than inferred solely from the mount generation.
This is one of the most important compatibility distinctions in Canon's history.
In 1987, Canon introduced the EOS system, whose fully electronic lens mount replaced FD.
Unlike the transition from breech-lock FD to New FD, the transition from FD to EOS was not backwards compatible.
EOS cameras use a different mounting interface and electronic communication system.
An FD lens cannot be attached directly to an EF camera body.
Although adapters exist, they introduce additional technical considerations.
Canon FD lenses were designed for a flange focal distance of 42mm.
The EF mount uses 44mm.
This difference means a conventional mechanical adapter cannot place an unmodified FD lens at the correct distance for infinity focus on an EF film camera.
An optical adapter may restore infinity focusing, but its additional elements can affect optical quality.
A purely mechanical adapter generally limits focusing to shorter distances.
Mirrorless cameras with shorter flange distances offer more practical opportunities for adapting FD lenses, although focusing and aperture operation remain manual unless specialized mechanisms are provided.
Canon's historical account of EOS development confirms that replacing the mechanical FD interface with fully electronic lens communication was central to the new system.
Collectors should not confuse the Canon EF camera introduced in 1973 with the EF lens mount introduced in 1987.
Despite its name, that 1973 model is an FD-mount film camera.
It therefore belongs to Canon's earlier manual-focus system rather than the later EOS line.
When purchasing an unfamiliar Canon lens, identify the actual mounting mechanism before attempting to install it.
Inspect the rear coupling levers for damage or deformation.
On breech-lock FD lenses, check that the locking ring operates correctly.
On New FD lenses, verify that the locking mechanism engages and releases normally.
Examine the aperture blades for oil, sticking or incomplete movement.
Check the focusing ring for excessive resistance or uneven travel.
Finally, document the exact model designation, optical generation and any identifying markings.
A lens described simply as Canon 50mm f/1.4 may belong to several generations with different dimensions, mechanisms and optical specifications.
Recording the precise model prevents confusion when comparing lenses or assembling a historically consistent camera system.
Yes. New FD lenses retain compatibility with the established FD system, including the Canon AE-1.
No. Conventional FL lenses lack the coupling required for the camera's shutter-priority automatic exposure. Stopped-down metering and manual exposure adjustment are required.
Not necessarily. The mounting mechanism is different, and some lens models received optical or mechanical revisions.
Not directly. EOS cameras use a different electronic mount. Adapting an FD lens requires additional hardware and may limit focusing or optical performance.
Canon's FL, FD and New FD systems represent successive stages in the development of mechanical lens-to-camera communication.
FL lenses established automatic diaphragm operation but generally required stopped-down metering.
FD introduced improved aperture coupling and supported more advanced exposure systems.
New FD refined the mounting mechanism while preserving compatibility with earlier FD cameras.
For collectors, correctly identifying these generations is essential when evaluating lenses, checking compatibility and documenting equipment.
To compare Canon film cameras, identify specific lens generations and organize a collection of interchangeable equipment, explore the Canon records in Camera_DATA.
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Canon produced several interchangeable-lens systems before introducing the EOS mount in 1987. Among the most important for collectors of manual-focus 35mm cameras are FL, FD and New FD.
These three lens generations share closely related mechanical mounting systems, but they do not provide identical camera functions.
The essential difference is that FL lenses generally require stopped-down metering, while FD and New FD lenses support full-aperture metering and compatible automatic-exposure systems. New FD lenses also introduced a different locking mechanism that made changing lenses more convenient.
Understanding these distinctions is particularly important when assembling a Canon system from equipment manufactured across several decades.
The Canon FL system appeared in 1964, replacing the earlier R mount used on Canonflex cameras.
FL lenses incorporated automatic diaphragm operation. This allowed photographers to compose and focus at maximum aperture before the camera stopped the diaphragm down for exposure.
However, FL lenses did not communicate their selected aperture to the camera through the later FD coupling mechanism.
On compatible metered cameras, exposure measurements therefore required the lens to be stopped down to its working aperture.
The Canon Pellix, introduced in 1965, was an important FL-mount camera equipped with through-the-lens metering.
Other FL bodies included the Canon FX, Canon FP and FT QL.
Although these cameras shared much of their mechanical architecture with later Canon cameras, their exposure-control capabilities were different.
The FD system arrived in 1971 alongside the professional Canon F-1 and the more accessible FTb.
Its major innovation was improved mechanical communication between lens and camera.
FD lenses incorporated additional aperture-coupling mechanisms that allowed compatible camera bodies to measure exposure with the diaphragm fully open.
The camera could determine the selected aperture without requiring the photographer to darken the viewfinder for every reading.
This system also made more advanced automatic exposure possible.
The breech-lock FD mount retained a rotating locking ring.
When attaching a breech-lock FD lens, the photographer positioned the lens against the camera and rotated the locking ring to secure it.
The main lens barrel remained stationary during this operation.
Canon introduced the New FD generation in 1979.
The principal mechanical change was the replacement of the externally operated breech-lock ring with a more convenient mounting mechanism.
New FD lenses attach with a twisting motion similar to a conventional bayonet lens.
However, their mating surfaces remain stationary as the outer lens assembly turns.
Importantly, New FD did not introduce a fundamentally incompatible lens system.
Breech-lock FD and New FD lenses are designed for the same group of camera bodies and retain the essential exposure-coupling functions.
Canon continued developing the New FD range until the transition to the EOS system and its electronic lens mount.
A Canon lens can often be identified from its name ring, mounting mechanism and rear coupling levers.
Most Canon FL lenses display the letters FL on their front name ring.
They use a rotating breech-lock ring at the rear.
Their aperture coupling is simpler than the later FD system because they lack the additional mechanism required to communicate aperture settings for full-aperture metering.
Some FL lenses also have a distinctive manual/automatic diaphragm control ring.
The exact arrangement varies between generations.
For example, Canon manufactured several versions of its FL 50mm f/1.4, including the redesigned FL 50mm f/1.4 II introduced in 1968.
Early FD lenses generally carry the letters FD and feature an external rotating locking ring.
Many early examples have a silver-coloured front section, informally known as the chrome nose.
Later versions adopted predominantly black finishes.
These cosmetic changes do not necessarily correspond to a new optical formula.
The aperture ring may also display an automatic-exposure setting marked A or, on some earlier versions, a green circular mark.
Early FD lenses contain additional mechanical coupling components absent from conventional FL lenses.
These components communicate aperture information to compatible cameras. The Canon FD 24mm f/2.8 S.S.C. is one documented example of this generation.
New FD lenses are readily distinguishable.
They lack the traditional externally operated breech-lock ring.
Instead, a release button near the rear of the lens disengages the locking mechanism.
The photographer rotates the lens assembly to mount or remove it.
New FD lenses also generally have a smaller profile, although dimensions vary considerably by model.
A collector should identify the mounting mechanism rather than relying exclusively on the colour or typography of the name ring.
| Characteristic | Canon FL | Canon FD | Canon New FD |
|---|---|---|---|
| Introduction | 1964 | 1971 | 1979 |
| Basic mounting interface | Breech-lock | Breech-lock | Twist-lock bayonet-style mechanism |
| Main lens locking method | Rotating ring | Rotating ring | Rotating lens assembly |
| Automatic diaphragm | Yes | Yes | Yes |
| Full-aperture metering coupling | No | Yes | Yes |
| Compatible automatic exposure | No FD-style AE coupling | Yes, body-dependent | Yes, body-dependent |
| Manual focus | Yes | Yes | Yes |
| Native compatibility with EOS cameras | No | No | No |
All three generations were designed primarily for the 24 × 36mm format.
These distinctions concern the conventional lens lines. Some specialized lenses and accessories have additional operating restrictions.
Yes, many Canon FL lenses can be mounted on FD camera bodies.
This backwards compatibility was an important feature of Canon's transition to the newer system.
However, mechanical compatibility must be distinguished from exposure compatibility.
An FL lens does not possess the same aperture-coupling mechanisms as an FD lens.
Consequently, using it on an FD camera generally requires stopped-down metering.
The Canon AE-1 normally provides shutter-priority automatic exposure with compatible FD lenses.
When an FD lens's aperture ring is placed in its automatic position, the camera can select the appropriate diaphragm opening.
An FL lens does not provide this coupling.
Instead, the photographer must select an aperture and use the camera's stopped-down metering procedure.
The exposure is then adjusted manually.
Canon explicitly describes this distinction in the AE-1 instruction manual.
The procedure should be followed carefully because the position of the stopped-down lever affects the camera's metering behaviour.
Purpose-built or early lenses may introduce further restrictions, so physical mounting alone should not be considered proof of full compatibility.
Yes.
The New FD mounting mechanism was designed to remain compatible with the established FD camera system.
A New FD lens can therefore be used on an early Canon F-1, FTb, AE-1 or other compatible FD body.
Similarly, a breech-lock FD lens can be used on later cameras such as the Canon AE-1 Program.
The method of attaching the lens differs, but the essential mechanical connections remain compatible.
This is particularly useful for photographers who want to combine an early mechanical body with later, smaller lenses.
However, certain viewfinder displays and specialized camera functions may vary between lens generations.
For example, lens aperture-ring placement can affect the direct optical display of aperture values on particular Canon New F-1 finder configurations.
These differences do not generally prevent normal photography.
Not automatically.
The introduction of New FD involved improvements in handling, dimensions and manufacturing, but optical changes must be evaluated individually.
A useful example is the Canon 50mm f/1.4.
Canon introduced the first FD 50mm f/1.4 in March 1971.
According to Canon's historical specifications, it uses 7 elements in 6 groups.
It has a minimum focusing distance of 0.45 metres, a 55mm filter thread and a weight of approximately 370 grams.
The New FD 50mm f/1.4 appeared in June 1979.
It also uses 7 elements in 6 groups, but Canon describes improvements intended to increase compactness and contrast.
The New FD model weighs approximately 235 grams and uses a 52mm filter thread.
Both focus down to 0.45 metres.
This comparison illustrates how lenses with identical focal lengths and maximum apertures may nevertheless differ significantly in construction and handling.
It also demonstrates why collectors should identify the exact generation rather than recording every Canon FD 50mm f/1.4 as a single undifferentiated item.
Canon used several coating designations during the FD period.
S.C. stands for Spectra Coating.
S.S.C. stands for Super Spectra Coating.
These coatings were developed to reduce unwanted reflections and improve contrast.
On many breech-lock FD lenses, the coating designation is engraved directly onto the front name ring.
However, Canon generally stopped displaying these designations on New FD lenses.
Therefore, the absence of S.C. or S.S.C. lettering does not mean that a New FD lens lacks sophisticated coatings.
The coating specification and optical construction should be checked for the exact model rather than inferred solely from the mount generation.
This is one of the most important compatibility distinctions in Canon's history.
In 1987, Canon introduced the EOS system, whose fully electronic lens mount replaced FD.
Unlike the transition from breech-lock FD to New FD, the transition from FD to EOS was not backwards compatible.
EOS cameras use a different mounting interface and electronic communication system.
An FD lens cannot be attached directly to an EF camera body.
Although adapters exist, they introduce additional technical considerations.
Canon FD lenses were designed for a flange focal distance of 42mm.
The EF mount uses 44mm.
This difference means a conventional mechanical adapter cannot place an unmodified FD lens at the correct distance for infinity focus on an EF film camera.
An optical adapter may restore infinity focusing, but its additional elements can affect optical quality.
A purely mechanical adapter generally limits focusing to shorter distances.
Mirrorless cameras with shorter flange distances offer more practical opportunities for adapting FD lenses, although focusing and aperture operation remain manual unless specialized mechanisms are provided.
Canon's historical account of EOS development confirms that replacing the mechanical FD interface with fully electronic lens communication was central to the new system.
Collectors should not confuse the Canon EF camera introduced in 1973 with the EF lens mount introduced in 1987.
Despite its name, that 1973 model is an FD-mount film camera.
It therefore belongs to Canon's earlier manual-focus system rather than the later EOS line.
When purchasing an unfamiliar Canon lens, identify the actual mounting mechanism before attempting to install it.
Inspect the rear coupling levers for damage or deformation.
On breech-lock FD lenses, check that the locking ring operates correctly.
On New FD lenses, verify that the locking mechanism engages and releases normally.
Examine the aperture blades for oil, sticking or incomplete movement.
Check the focusing ring for excessive resistance or uneven travel.
Finally, document the exact model designation, optical generation and any identifying markings.
A lens described simply as Canon 50mm f/1.4 may belong to several generations with different dimensions, mechanisms and optical specifications.
Recording the precise model prevents confusion when comparing lenses or assembling a historically consistent camera system.
Yes. New FD lenses retain compatibility with the established FD system, including the Canon AE-1.
No. Conventional FL lenses lack the coupling required for the camera's shutter-priority automatic exposure. Stopped-down metering and manual exposure adjustment are required.
Not necessarily. The mounting mechanism is different, and some lens models received optical or mechanical revisions.
Not directly. EOS cameras use a different electronic mount. Adapting an FD lens requires additional hardware and may limit focusing or optical performance.
Canon's FL, FD and New FD systems represent successive stages in the development of mechanical lens-to-camera communication.
FL lenses established automatic diaphragm operation but generally required stopped-down metering.
FD introduced improved aperture coupling and supported more advanced exposure systems.
New FD refined the mounting mechanism while preserving compatibility with earlier FD cameras.
For collectors, correctly identifying these generations is essential when evaluating lenses, checking compatibility and documenting equipment.
To compare Canon film cameras, identify specific lens generations and organize a collection of interchangeable equipment, explore the Canon records in Camera_DATA.