what was first Canon to use AE on newly introduced FD lenses?

Theo Sulphate · Nov 1, 2018

When Canon introduced the FD-mount lenses in March of 1971 (silver breech lock version), which camera made use of shutter-priority AE with these lenses?

It seems to me that in 1971 no Canon could use the "o" (later "A") AE setting on those lenses.

That can't be right - I must be overlooking something.

MattKing · Nov 1, 2018

The FTb and original F1 were the two cameras that were introduced in 1971 with the FD mount lenses, and you are correct that they made no use of the "o" (later "A") setting.
But the EF followed two years later in 1973, and it did offer auto exposure and made use of the "o".
I can only assume that the EF was already on the drawing board in 1971.

cooltouch · Nov 1, 2018

Actually, the original F-1 had an optional Servo EE finder that provided the camera with shutter priority auto exposure. It's big and bulky and requires an accessory battery pack, but it worked. So the answer is actually the original 1971 F-1.

Here's a shot, borrowed from the Mir website, showing the F-1 with Servo EE Finder and its accessory battery pack:

Theo Sulphate · Nov 1, 2018

Yow! A heavy price to pay for shutter priority.

But wait: the servo EE actually moves the aperture ring! It is not making use of the "o" / "A" setting on the lens.

If the Canon EF was the first to use AE, that means when the FD lenses were introduced years earlier, people could only wonder what that "o" setting was for.

AgX · Nov 1, 2018

Theo Sulphate said:
But wait: the servo EE actually moves the aperture ring! It is not making use of the "o" / "A" setting on the lens.

You mix things up.
That remark on the MIR site concerning actually twisting the aperture dial is refering to Nikon AE finders.

The Canon F-1 Servo EE Finder actuates the aperture simulator/control lever in the FD-mount.
Thus it was the first device to employ this FD-mount feature, assuming it was on the market in 1971.

Theo Sulphate · Nov 1, 2018

AgX said:
...
The Canon F-1 Servo EE Finder actuates the aperture simulator/control lever in the FD-mount.
Thus it was the first device to employ this FD-mount feature, assuming it was on the market in 1971.

Yes, I see that now. Thank you.

Laurent · Nov 1, 2018

cooltouch said:
Actually, the original F-1 had an optional Servo EE finder that provided the camera with shutter priority auto exposure. It's big and bulky and requires an accessory battery pack, but it worked. So the answer is actually the original 1971 F-1.

Here's a shot, borrowed from the Mir website, showing the F-1 with Servo EE Finder and its accessory battery pack:

I owned one of these beasts, and stupidly sold it 'cause I needed cash. I won't say it was practical, but I love the feeling of this camera.

benjiboy · Nov 1, 2018

The Canon EF was the first FD camera to have inbuilt shutter priority AE in 1978.

AgX · Nov 1, 2018

The EF was introduced in 1973, thus it took about three years for that feature to be used on the new FD-lenses, leaving that weird EE-finder aside.
But even before that one could meter with preset aperture in open-aperture mode with a FTb. That aperture-simulator lever was thus actually not idle for these years...

benjiboy · Nov 1, 2018

AgX said:
The EF was introduced in 1973, thus it took about three years for that feature to be used on the new FD-lenses, leaving that weird EE-finder aside.
But even before that one could meter with preset aperture in open-aperture mode with a FTb. That aperture-simulator lever was thus actually not idle for these years...

you're right it was 1973, not 1976 but the chrome nosed FD range of lenses that had a green o below the smallest aperture marking that put the lens into the AE mode was first marketed by Canon in. March 1971 so they were available for both the F1 Servo- EE Finder and the EF at the time they were introduced.

cooltouch · Nov 2, 2018

AgX said:
The EF was introduced in 1973, thus it took about three years for that feature to be used on the new FD-lenses, leaving that weird EE-finder aside.
But even before that one could meter with preset aperture in open-aperture mode with a FTb. That aperture-simulator lever was thus actually not idle for these years...

I think you're referring to stop down metering, which the FTb and most FD cameras have. This feature was a holdover from the way metering was done on the FL cameras which predated the FD cameras. Neither FL cameras nor FL lenses support full aperture metering. They meter when an FL lens is stopped down. With the FTb (and F-1 and EF, the two other cameras that use the same multi-lever arrangement -- well, the EF's is a little different, but close enough), the lever can be locked into the stop-down position, thus setting things up for the situation you describe. FD cameras originally had this feature to ensure backward compatibility with FL lenses. Still, it bears mentioning that the aperture ring on FD lenses, when mounted to the FTb, is impossible to move to the "o" or "A" position.

AgX · Nov 2, 2018

No, instead I was referring to open aperture metering.
The Ftb yields that feature, but of course necessitates for this a FD-lens. Thus the FD-lenses were useful before there was any shutter-priority autoexposure at any Canon FD camera.

Theo Sulphate · Nov 2, 2018

AgX said:
... open aperture metering. ... Thus the FD-lenses were useful before there was any shutter-priority autoexposure at any Canon FD camera.

Good point.

Also, as Michael mentioned, you can't select o/A on the lens when it's mounted on an FTb, but I wonder how many people have made the same mistake I did a few years ago: for only $10 I bought a mint condition FTb that operated perfectly and I wanted to put a lens on it. I happened to grab one of my FD lenses set to A and much time passed before I realized why I couldn't mount it.

AgX · Nov 2, 2018

The FD-mount had to be introduced as open-aperture metering was going to be a standard feature with SLRs.

That it was designed that way that the aperture-simulator can be used in addition as aperture-control, and thus enabling shutter-priority AE as the more complicated form of AE, was an additional feature.

Keeping the mount backwards-compatible resulted in its rather cluttered appearance with 4 actuators.

That a completely different approach, still maintaining backwards-compatibility, was possible prooved the Praktica Electric-mount. That one could have even been desinged to also incorporate shutter-priority AE capability, but that would have been very tricky, if it worked at all.
When whining over the complicated FD-mount one should that all have in mind.

cooltouch · Nov 2, 2018

AgX, after rereading your posts, I'm still a bit confused because of your terminology. Can you describe in more detail this "aperture simulator"? Are you referring to the stop-down lever? It's the only thing I can think of on a camera such as the FTb that, when engaged, turns the camera into one that's metering based on the aperture selected.

Regarding the "overly complex" FD mount, I guess my comment is that it's all relative. My first real 35mm camera was a Canon AE-1 and within a few years of its purchase, I'd added another four FD cameras to my collection -- along with a decent selection of lenses, both nFD and the older breechlock style. So to me, that was the only mount I knew and I just accepted it for what it was. I even took the time to learn its components, how they worked and what they meant and it all made sense to me. It wasn't until several years later that I was exposed to a different mount -- Nikon -- where I could even appreciate a simpler mount design. Simpler, but not necessarily better. More conducive to the addition of AF, however. I'll give Nikon that much.

AgX · Nov 2, 2018

cooltouch said:
AgX, after rereading your posts, I'm still a bit confused because of your terminology. Can you describe in more detail this "aperture simulator"? Are you referring to the stop-down lever? It's the only thing I can think of on a camera such as the FTb that, when engaged, turns the camera into one that's metering based on the aperture selected

Canon employed basically two actuators

-) Automatic Diaphragm lever (that big lever...)

It actually drives the diaphragm in closing. It goes to completion so to say and makes it easy for the camera to actuate it. Just drive it full... The preset setting at the lens will take control and in effect disengage it once the preset aperture value has been reached in closing.

-) Aperture Simulator / Aperture Control lever (that small lever...)

When using the lens in open-aperture mode with preset-aperture, this lever will tell the camera body on what aperture settting the metering or the auto-exposure has to be based on. That is why it is called aperture simulator.
This feature is substantial in any kind of open-aperture metering. The Practica Electric mount instead of a lever offered the camera a varying electrical resistance to indicate the aperture preset at the lens.

When in shutter-priority autoexposure-mode the same lever changes its role from being active to being passive. Now it is the camera body that swings this lever to a degree that at the respective, pre-calculated diaphragm opening the action of the automatic-diasphragm lever will be disengaged. That is why I call it also aperture control lever.

In addition there are

-) Lens Speed indicator
Informing the camera body on what aperture any reading at open aperture is to be based on.
(Is it the scene that is dark, or is it the low speed of a lens that makes a scene look dark...)

-) Auto-mode indicator
Informing the camera body whether one wants to work in manual- or auto-mode.

cooltouch · Nov 3, 2018

I know all that stuff. I was just confused with your terminology. What you're referring to as an "aperture simulator" I'm used to seeing referenced as a "signal pin." See:

https://en.wikipedia.org/wiki/Canon_FD_lens_mount

AgX · Nov 3, 2018

"Signal Pin" is a stupid term. It can mean anything. And would make one rather think of the last pin I listed above.

In any FD-literature I got that lever is called aperture simulator. For anyone knowing the function of the FD-mount that term should be selfexplanatory.

In one non-Canon repair manual this very lever is designated diaphragma setting lever. In another by seeemingly the same author diaphragma control lever is used.

The original Canon term in parts list is diaphragma signal lever.

cooltouch · Nov 3, 2018

I'll go with the original Canon term.

Theo Sulphate · Nov 4, 2018

It is good to read these explanations of how the FD-mount mechanism functions; I have not found a description elsewhere.

The first and only mount I knew for 15 years was the M42 mount. It was easy to understand.

Then, even though I bought Canon before Nikon, I had only one lens - which I never removed. So, its mechanism was invisible to me. When I became interested in Nikon, the F-mount seemed very logical and bot complex at all. Only after buying more FD lenses and trying to test them without a camera did I notice all those linkages. I did wonder about the complexity.

cooltouch · Nov 4, 2018

Theo Sulphate said:
Only after buying more FD lenses and trying to test them without a camera did I notice all those linkages. I did wonder about the complexity.

Avoiding patent infringement, possibly? The Nikon F was introduced in 1959, so patent restrictions would have still been in effect in 1971. Assuming that any patents associated with the Nikon F mount were filed in 1959, of course.

what was first Canon to use AE on newly introduced FD lenses?

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