«The XXX Exposure Meter is Cross-Coupled ...»

[Sumarongi]

Of course I know that the Kodak Retina IIIS was a very early specimen offering cross-coupled exposure metering, and it was certainly one of the very few true system CRF cameras having that feature; certainly also the Nikon F was an early implementer —— albeit in the latter case with «Exakta-like crudity», if I recall your words correctly, dear Roger 🙂

Thus ... my question is, dear Roger, and dear all:

Who exactly did enable cross-coupled exposure metering in 35mm still cameras equipped with fully interchangeable objectives, and when exactly?

(I do have a certain suspicion who the person in question was, but I'm not absolutely sure...)

 

[johnf04]

Agfaflex slrs from the late 1950s had cross coupled metering, although it was not TTL, and had a readout on the camera top.

 

[Sarcophilus Harrisii]

Sorry, what do you mean by cross-coupled? Some earlier cameras would have uncoupled meters fitted, eventually connecting them to shutter and/or aperture was implemented. Cross-coupled, isn't a term I am particularly familiar with.

The original Contaflex Super was another 1950s SLR with coupled non-TTL selenium meter as was the Voigtländer Bessamatic.

 

[Sumarongi]

Sorry, what do you mean by cross-coupled?

Exactly this:

Some earlier cameras would have uncoupled meters fitted, eventually connecting them to shutter and/or aperture was implemented. Cross-coupled, isn't a term I am particularly familiar with.

The original Contaflex Super was another 1950s SLR with coupled non-TTL selenium meter as was the Voigtländer Bessamatic.

You're right, the term "crosscoupling" is actually organic chemistry, in English; later, the term appears in many camera manuals (e.g. Leicaflex).
-- I presume, initially the term may have been a mirror translation, and they perhaps weren't aware that it already had a very distinct meaning in English organic chemistry parlance... or they used it deliberately, like a pun?

I guess "fully coupled" is an alternative term?

 

[Kai-san]

I believe the most common terms in use are coupled and uncoupled. These should also be the easiest to understand.

 

[Sumarongi]

I believe the most common terms in use are coupled and uncoupled. These should also be the easiest to understand.

You're right, but: the dichotomy "coupled" vs. "uncoupled" is imprecise.

If the exposure meter is coupled to the shutter speed, but not coupled to the diaphragm, one is in a dilemma -- is it coupled, or uncoupled?

"Fully coupled" or "cross-coupled" makes it clear that the meter has to be coupled to the diaphragm-adjusting member *and* to the shutter speed-adjusting member.

BTW, on camera-wiki.org they use the term "cross-coupled" quite regularly, e.g.:

http://camera-wiki.org/wiki/Minolta_Minoltina_AL-S
http://camera-wiki.org/wiki/Minolta_Minoltina-P
http://camera-wiki.org/wiki/Konica_FM
http://camera-wiki.org/wiki/Konica_F

 

[Kai-san]

I would say that if the meter controls either shutter, aperture or both, then it is coupled. If the meter controls the shutter, it is an aperture priority camera. If the meter controls the aperture you have a shutter priority camera. In more modern cameras where it can control both, you either switch between aperture or shutter priority and/or you have a programmed auto mode.

But the word cross-coupled will not tell me whether a camera has several metering modes or if it's auto only. That's why I think it's more confusing than helpful. But that's only my personal view on the matter.

 

[Sumarongi]

I would say that if the meter controls either shutter, aperture or both, then it is coupled. If the meter controls the shutter, it is an aperture priority camera. If the meter controls the aperture you have a shutter priority camera. In more modern cameras where it can control both, you either switch between aperture or shutter priority and/or you have a programmed auto mode.

But the word cross-coupled will not tell me whether a camera has several metering modes or if it's auto only. That's why I think it's more confusing than helpful. But that's only my personal view on the matter.

Well, e.g. Roger Hicks uses the term "cross-coupled" in his books; and it was also Nikon's terminology at least during the 1960s:

 

[Sumarongi]

Additions re terminology:

Also Yashica were calling their exposure meter "cross-coupled":
https://www.pacificrimcamera.com/rl/00812/00812.pdf

Re Nikon, also after the 1960s they were using this term; for example, see https://www.mir.com.my/rb/photography/hardwares/manuals/fmfefa/fm.pdf

—— on p. 22:
«EXPOSURE MEASUREMENT
The Nikon FM’s built-in exposure meter utilizes Nikon’s
proven center-weighted through-the-lens metering system
which is cross-coupled with both the shutter speed control of
the camera and the aperture control of the lens mounted on
the camera. [...]»

—— on p. 34:
«Exposure metering: Through-the-lens, center-weighted, full
aperture exposure measurement with Nikkor lenses fitted with
meter coupling ridge; stop-down exposure measurement ap-
plies for other lenses; exposure correctly set by adjusting
shutter speed and/or lens aperture until correct exposure in-
dicator LED lights up; meter cross-coupled with both lens
diaphragm and shutter speed controls; metering range EV 1
to EV 1 8 (i.e., f/1.4,1 sec. ~ f/16,1/1000 sec.) with 50mm f/
1.4 lens at ASA 100; built-in meter coupling lever can be
locked up, enabling use with both Al-type and non-AI-type
Nikkor lenses; ASA range 12 ~ 3200; [...]»

 

[ColSebastianMoran]

I thought you were talking about the LVS system, in which you set exposure, then if you change aperture or shutter-speed, the other changes correspondingly to hold exposure constant.

I thought the IIIs implementation of this idea a PITA.

 

[Sumarongi]

I thought you were talking about the LVS system, in which you set exposure, then if you change aperture or shutter-speed, the other changes correspondingly to hold exposure constant.

I thought the IIIs implementation of this idea a PITA.

To an extent, I agree with you: the elaborated cases of LVS/EVS are of course cross-coupled in the beforementioned sense; the Kodak Retina IIIS at least doesn't use the terms LVS/EVS, but in a nutshell, it probably belongs to that group. —— Anyways, with the bottom wheel there's a simple override possible, I'd say?

Indeed, "cross-coupled" exposure meters are not necessarily of the LVS/EVS type; see the examples of Leicaflex, Nikon, Yashica, and so forth.

 

[markjwyatt]

bad information

 

[Sumarongi]

bad information

😕

You speak in riddles...

 

[Sumarongi]

One hint I might add:

US patent 2,929,308 ...