Pondering Functionality

JimKramer wrote:
> Wilba wrote:
> <Snip>
>>
>> Yeah, but I'm talking about what _I_ want, not what the camera
>> manufacturers or the ignorant want.
>
> Well that simplifies everything. They just need to spend more in
> marketing to convince you that they already offer everything you
> could ever want in a camera.

I have a better idea. Give me my share of the marketting budget to spend on
a new camera.
 >> Stay informed about: Pondering Functionality 

l v wrote:
> Wilba wrote:
>> l v wrote:
>>> Wilba wrote:

>>>> Can you change the ISO with one touch [on a 40D]?
>>>> Do they [40Ds] do "auto ISO"?
>>>>
>>>> It's not about the wheels.
>>>
>>> On the Canon 40d, changing ISO is a two step process. The ISO
>>> button is directly behind the finger wheel - tap it with your index
>>> finger.
>>> You then use the finger wheel to change the ISO, same finger. Auto
>>> ISO is directly below 100 ISO.
>>
>> Ah, thanks, I see it now. If instead of the three buttons to the left of
>> the ISO button there were an aperture button, a shutter speed button, and
>> an exposure compensation button, that would be a suitable user interface
>> to provide the functionality I want.
>
> I think you are missing the point of what Wolfgang posted.

I think Wolfgang is missing the point of what I posted.

> I think you'll find that Canon did a better design than what you are
> suggesting.

OK, let's acknowledge that we disagree and see if something interesting
comes of it ...

> Exposure comp button is the same button as ISO, use the thumb wheel vs the
> finger wheel.
>
> Depending on the camera's mode (manual, shutter priority, aperture
> priority, etc) the finger wheel and thumb wheel make all of the necessary
> changes you are wanting do do with individual buttons.
>
> When in Av (aperture mode), the finger wheel adjusts the aperture setting
> and the thumb wheel adjusts the exposure comp - letting the camera
> calculate the shutter speed.
>
> When in Tv (shutter mode), the finger wheel adjusts the shutter speed and
> the thumb wheel adjusts the exposure comp - letting the camera calculate
> the aperture.
>
> When in P (program mode), the finger wheel shifts the exposure (both
> shutter and aperture) keeping the exposure the same.
>
> When in M (manual mode), the finger wheel adjusts the shutter speed and
> the thumb wheel adjusts the aperture.
>
> Tap the shutter without taking a photo and your settings are set.

I don't dispute that a 40D and my fantasy camera can be set up to operate
the same way. The difference that makes a difference is how you get there.

The key thing in what you said is, "Depending on the camera's mode". I'm
suggesting in effect abandoning the conventional modes, and directly
controlling the four parameters independently at the user interface level.
The four parameters are only in any sense dependent when any one or more are
set to "auto", and the camera is given the responsibility for chosing the
parameter's value.

I don't want to have to remember and think my way through all the
information contained in your preceding seven paragraphs. I want to change
the four parameters directly according to my whim.

In many cases doing that won't be more or less efficient than achieving the
same effect with conventional modes. For instance, if you want to go from
aperture priority to shutter priority (without any change to ISO and
compensation), on a conventional camera you would turn the mode dial to
shutter priority and set the desired shutter speed, and on mine you would
set the aperture to auto and set the desired shutter speed. In both cases
you need two touches.

I see current DSLR user interface design as being stuck on an evolutionary
path. With manual cameras, you set the shutter speed and aperture to suit
the fixed film sensitivity, and made exposure compensations by fudging the
shutter speed or aperture.

With built-in meters came the ability to have a mode in which the shutter
speed or aperture was chosen by the camera. Exposure compensation could be
achieved by fudging the film sensitivity.

With more electronic control came the ability to have the camera choose
either shutter speed, aperture, or both. It made sense to label each of
those options as a "mode".

Now that sensitivity is as flexible as shutter speed or aperture, you need
to define and operate 2x2x2 = 8 distinct modes (manual or automatic for
three parameters). Rather than remember a three-dimensional matrix of modes,
and which user interface control does what in each mode, I want to simply
set the desired value for each of the four parameters, via dedicated
controls.
 >> Stay informed about: Pondering Functionality 

Wilba <wilba.DeleteThis@CUTTHISimago.com.au> wrote:
> Wolfgang Weisselberg wrote:
>> Wilba wrote:
>>> Wolfgang Weisselberg wrote:
>>>> Wilba wrote:

>>> Can you change the ISO with one touch?

>> Define "one touch".

> Touching one control once to effect a change. Contrast with "two touch", for
> instance, holding down a button while turning a wheel.

Then it's one touch: you press the iso-botton once, twirl the
back wheel and there you go. No need to hold down any button.

I guess you want to rework/expand your one-touch/two-touch with
things like "modal control".

>> Explain why "one touch" is more important to ISO than
>> aperture/exposure/shift/comp. Explain how analog photographers
>> survived.

> The functionality I described in the original post is best supported by a
> user interface with one touch controls.

Proof?

-Wolfgang
 >> Stay informed about: Pondering Functionality 

Chris Malcolm <cam DeleteThis @holyrood.ed.ac.uk> wrote:
> Wolfgang Weisselberg <ozcvgtt02 DeleteThis @sneakemail.com> wrote:
>> Wilba <wilba DeleteThis @CUTTHISimago.com.au> wrote:
>>> Wolfgang Weisselberg wrote:
>>>> Wilba wrote:

>>> Can you change the ISO with one touch?

>> Define "one touch".
>> Explain why "one touch" is more important to ISO than
>> aperture/exposure/shift/comp.

> Sometimes when the opportunity for a fast action shot turns up
> unexpectedly while you were carefully shooting low ISO high-quality
> images, you want to be able to change as fast as possible to a high
> ISO and shutter priority before the opportunity has gone.

I can do that. Blindly ...

>> Explain how analogue photographers survived.

> To switch rapidly from high quality tripod landscape to fast action
> capture they carried two cameras loaded with different films.

.... and faster than switching around cameras.

-Wolfgang
 >> Stay informed about: Pondering Functionality 

Wilba <wilba.DeleteThis@CUTTHISimago.com.au> wrote:

> The key thing in what you said is, "Depending on the camera's mode". I'm
> suggesting in effect abandoning the conventional modes,

No Tv, Av, P, M any more?
Hmmm.
But hey, *I* am using a moded editor (vim), while most of
the world uses modeless editors. I switch to input or
replace mode --- otherwise my keys don't enter text but
execute commands. 'You' just type.

> and directly
> controlling the four parameters independently at the user interface level.

You cannot!
ISO, Exposure, Aperture, compensation. That's only 3 degrees of
freedom. Set any 3 and the 4th is necessarily derived from them.

> I don't want to have to remember and think my way through all the
> information contained in your preceding seven paragraphs. I want to change
> the four parameters directly according to my whim.

I want to fly by waving my hands around, according to my whim ---
and stand a better chance of getting my wish.

The correct idea is to *learn* how to use your tool --- and once
you understand that the finger directs and the thumb corrects,
everything is absolutely clear.

> In many cases doing that won't be more or less efficient than achieving the
> same effect with conventional modes. For instance, if you want to go from
> aperture priority to shutter priority (without any change to ISO and
> compensation), on a conventional camera you would turn the mode dial to
> shutter priority and set the desired shutter speed, and on mine you would
> set the aperture to auto and set the desired shutter speed. In both cases
> you need two touches.

Aeh, how do you set your aperture to auto? Press a button?
Or twirl the wheel from f/5.6 to f/44+ (or f/1.0 --- I have
an f/1.4 lens on the camera by default)? The latter would be
extraordinarily stupid, because it
a) takes too long
b) destroys pre-set settings

With Canon, if I switch from Av to Tv, I get the same setting
for exposure as I had last time on Tv --- so I can choose usable
presets. I only wish Canon had a few 'customer presets', so I
could set one e.g. to ISO 1600, Tv, Comp-1, 1/60s for available
light (or even better, a custom 3D-curve that balances between ISO,
time and aperture in what _I_ deem as good for available light) ---
just turn the mode wheel and there you go, all (pre)set, one touch.

> I see current DSLR user interface design as being stuck on an evolutionary
> path.

So are human hands. Overcomplicated, easily broken, with fingers
that can bend just one way --- your neck can even rotate!

> Now that sensitivity is as flexible as shutter speed or aperture, you need
> to define and operate 2x2x2 = 8 distinct modes (manual or automatic for
> three parameters).

Please explain why one _needs_ to define and operate 8 different
modes.

-Wolfgang
 >> Stay informed about: Pondering Functionality 

Wilba wrote:

> Now that sensitivity is as flexible as shutter speed or aperture, you need
> to define and operate 2x2x2 = 8 distinct modes (manual or automatic for
> three parameters). Rather than remember a three-dimensional matrix of modes,
> and which user interface control does what in each mode, I want to simply
> set the desired value for each of the four parameters, via dedicated
> controls.

What determines the auto parameter(s)?

fix shutter & aperture; auto ISO
fix shutter & ISO; auto aperture
fix aperture & ISO; auto shutter

-exposure compensation modifies the auto

-leave two on auto & the camera has to guess the priority of the
remaining two.

I've not even tried the P mode but isn't that supposed to let you adjust
shutter & aperture at the wheels, alternately? Does that effectively
switch between shutter & aperture priority? I suspect program mode is
too clever & I wouldn't know what it's doing. So your system would put
it in manual unless one control was set to auto? And two set to auto
would turn off the previous leaving the most recent control on auto?

Or like auto ISO, you'd set a trigger level for each control. ISO
increases if the aperture is already wide open; aperture opens to keep
the shutter above the minimum speed. Too many options to keep track of
perhaps.
 >> Stay informed about: Pondering Functionality 

Wilba wrote:
> l v wrote:
>> Wilba wrote:
>>> l v wrote:
>>>> Wilba wrote:
>
>>>>> Can you change the ISO with one touch [on a 40D]?
>>>>> Do they [40Ds] do "auto ISO"?
>>>>>
>>>>> It's not about the wheels.
>>>> On the Canon 40d, changing ISO is a two step process. The ISO
>>>> button is directly behind the finger wheel - tap it with your index
>>>> finger.
>>>> You then use the finger wheel to change the ISO, same finger. Auto
>>>> ISO is directly below 100 ISO.
>>> Ah, thanks, I see it now. If instead of the three buttons to the left of
>>> the ISO button there were an aperture button, a shutter speed button, and
>>> an exposure compensation button, that would be a suitable user interface
>>> to provide the functionality I want.
>> I think you are missing the point of what Wolfgang posted.
>
> I think Wolfgang is missing the point of what I posted.
>
>> I think you'll find that Canon did a better design than what you are
>> suggesting.
>
> OK, let's acknowledge that we disagree and see if something interesting
> comes of it ...
>
>> Exposure comp button is the same button as ISO, use the thumb wheel vs the
>> finger wheel.
>>
>> Depending on the camera's mode (manual, shutter priority, aperture
>> priority, etc) the finger wheel and thumb wheel make all of the necessary
>> changes you are wanting do do with individual buttons.
>>
>> When in Av (aperture mode), the finger wheel adjusts the aperture setting
>> and the thumb wheel adjusts the exposure comp - letting the camera
>> calculate the shutter speed.
>>
>> When in Tv (shutter mode), the finger wheel adjusts the shutter speed and
>> the thumb wheel adjusts the exposure comp - letting the camera calculate
>> the aperture.
>>
>> When in P (program mode), the finger wheel shifts the exposure (both
>> shutter and aperture) keeping the exposure the same.
>>
>> When in M (manual mode), the finger wheel adjusts the shutter speed and
>> the thumb wheel adjusts the aperture.
>>
>> Tap the shutter without taking a photo and your settings are set.
>
> I don't dispute that a 40D and my fantasy camera can be set up to operate
> the same way. The difference that makes a difference is how you get there.
>
> The key thing in what you said is, "Depending on the camera's mode". I'm
> suggesting in effect abandoning the conventional modes, and directly
> controlling the four parameters independently at the user interface level.
> The four parameters are only in any sense dependent when any one or more are
> set to "auto", and the camera is given the responsibility for chosing the
> parameter's value.
>
> I don't want to have to remember and think my way through all the
> information contained in your preceding seven paragraphs. I want to change
> the four parameters directly according to my whim.

It's really quite easy. Nothing to remember and quite intuitive after a
minute of using the camera. The finger wheel adjust the camera's mode.

>
> In many cases doing that won't be more or less efficient than achieving the
> same effect with conventional modes. For instance, if you want to go from
> aperture priority to shutter priority (without any change to ISO and
> compensation), on a conventional camera you would turn the mode dial to
> shutter priority and set the desired shutter speed, and on mine you would
> set the aperture to auto and set the desired shutter speed. In both cases
> you need two touches.

It seems like it would be two touches of all of the buttons to get what
the dial achieves in one quick rotate. It seems that if I want
aperture, I need to push the aperture button and set it to "auto", then
push the shutter button to set it. Having a mode dial, makes quick work
of it, all can be done while looking through the view finder, and it
remembers my last settings.

>
> I see current DSLR user interface design as being stuck on an evolutionary
> path. With manual cameras, you set the shutter speed and aperture to suit
> the fixed film sensitivity, and made exposure compensations by fudging the
> shutter speed or aperture.

I remember those days.

>
> With built-in meters came the ability to have a mode in which the shutter
> speed or aperture was chosen by the camera. Exposure compensation could be
> achieved by fudging the film sensitivity.

That is all the exp comp ring did on my camera.

>
> With more electronic control came the ability to have the camera choose
> either shutter speed, aperture, or both. It made sense to label each of
> those options as a "mode".
>
> Now that sensitivity is as flexible as shutter speed or aperture, you need
> to define and operate 2x2x2 = 8 distinct modes (manual or automatic for
> three parameters). Rather than remember a three-dimensional matrix of modes,
> and which user interface control does what in each mode, I want to simply
> set the desired value for each of the four parameters, via dedicated
> controls.
>

That would be manual mode, right?

>


--

Len
 >> Stay informed about: Pondering Functionality 

Paul Furman wrote:
> Wilba wrote:
>
>> Now that sensitivity is as flexible as shutter speed or aperture, you
>> need to define and operate 2x2x2 = 8 distinct modes (manual or
>> automatic for three parameters). Rather than remember a
>> three-dimensional matrix of modes, and which user interface control
>> does what in each mode, I want to simply set the desired value for
>> each of the four parameters, via dedicated controls.
>
> What determines the auto parameter(s)?
>
> fix shutter & aperture; auto ISO
> fix shutter & ISO; auto aperture
> fix aperture & ISO; auto shutter
>
> -exposure compensation modifies the auto
>
> -leave two on auto & the camera has to guess the priority of the
> remaining two.
>
> I've not even tried the P mode but isn't that supposed to let you adjust
> shutter & aperture at the wheels, alternately? Does that effectively
> switch between shutter & aperture priority? I suspect program mode is
> too clever & I wouldn't know what it's doing. So your system would put
> it in manual unless one control was set to auto? And two set to auto
> would turn off the previous leaving the most recent control on auto?

P mode is the same as auto except it will not pop the flash up if the
shutter falls below a set threshold. The finger wheel allows you to
shift the "program". If the camera calculates f/stop = 5.6 and 1/250s,
rotating the finger wheel one way will increase the f/stop and decrease
the shutter keeping the exposure the same. Rotating the finger wheel
the other way will decrease the f/stop and increase the shutter keeping
the exposure the same.

>
> Or like auto ISO, you'd set a trigger level for each control. ISO
> increases if the aperture is already wide open; aperture opens to keep
> the shutter above the minimum speed. Too many options to keep track of
> perhaps.


--

Len
 >> Stay informed about: Pondering Functionality 

l v wrote:
> Paul Furman wrote:
>> Wilba wrote:
>>
>>> Now that sensitivity is as flexible as shutter speed or aperture, you
>>> need to define and operate 2x2x2 = 8 distinct modes (manual or
>>> automatic for three parameters). Rather than remember a
>>> three-dimensional matrix of modes, and which user interface control
>>> does what in each mode, I want to simply set the desired value for
>>> each of the four parameters, via dedicated controls.
>>
>> What determines the auto parameter(s)?
>>
>> fix shutter & aperture; auto ISO
>> fix shutter & ISO; auto aperture
>> fix aperture & ISO; auto shutter
>>
>> -exposure compensation modifies the auto
>>
>> -leave two on auto & the camera has to guess the priority of the
>> remaining two.
>>
>> I've not even tried the P mode but isn't that supposed to let you
>> adjust shutter & aperture at the wheels, alternately? Does that
>> effectively switch between shutter & aperture priority? I suspect
>> program mode is too clever & I wouldn't know what it's doing. So your
>> system would put it in manual unless one control was set to auto? And
>> two set to auto would turn off the previous leaving the most recent
>> control on auto?
>
> P mode is the same as auto except it will not pop the flash up if the
> shutter falls below a set threshold. The finger wheel allows you to
> shift the "program". If the camera calculates f/stop = 5.6 and 1/250s,
> rotating the finger wheel one way will increase the f/stop and decrease
> the shutter keeping the exposure the same. Rotating the finger wheel
> the other way will decrease the f/stop and increase the shutter keeping
> the exposure the same.

So yes, P-mode switches between shutter & aperture priority. Then you
just need a way to adjust the auto-ISO trigger to a shutter speed based
on zoom

>> Or like auto ISO, you'd set a trigger level for each control. ISO
>> increases if the aperture is already wide open; aperture opens to keep
>> the shutter above the minimum speed. Too many options to keep track of
>> perhaps.
>
>
 >> Stay informed about: Pondering Functionality 

Paul Furman wrote:
> l v wrote:
>> Paul Furman wrote:
>>> Wilba wrote:
>>>
>>>> Now that sensitivity is as flexible as shutter speed or aperture,
>>>> you need to define and operate 2x2x2 = 8 distinct modes (manual or
>>>> automatic for three parameters). Rather than remember a
>>>> three-dimensional matrix of modes, and which user interface control
>>>> does what in each mode, I want to simply set the desired value for
>>>> each of the four parameters, via dedicated controls.
>>>
>>> What determines the auto parameter(s)?
>>>
>>> fix shutter & aperture; auto ISO
>>> fix shutter & ISO; auto aperture
>>> fix aperture & ISO; auto shutter
>>>
>>> -exposure compensation modifies the auto
>>>
>>> -leave two on auto & the camera has to guess the priority of the
>>> remaining two.
>>>
>>> I've not even tried the P mode but isn't that supposed to let you
>>> adjust shutter & aperture at the wheels, alternately? Does that
>>> effectively switch between shutter & aperture priority? I suspect
>>> program mode is too clever & I wouldn't know what it's doing. So your
>>> system would put it in manual unless one control was set to auto? And
>>> two set to auto would turn off the previous leaving the most recent
>>> control on auto?
>>
>> P mode is the same as auto except it will not pop the flash up if the
>> shutter falls below a set threshold. The finger wheel allows you to
>> shift the "program". If the camera calculates f/stop = 5.6 and
>> 1/250s, rotating the finger wheel one way will increase the f/stop and
>> decrease the shutter keeping the exposure the same. Rotating the
>> finger wheel the other way will decrease the f/stop and increase the
>> shutter keeping the exposure the same.
>
> So yes, P-mode switches between shutter & aperture priority. Then you
> just need a way to adjust the auto-ISO trigger to a shutter speed based
> on zoom
>

Not exactly, P-mode does not switch between shutter & aperture priority
per se. It allows you to override the shutter/aperture settings
calculated by the camera keeping the same exposure.

For example, if the camera calculates a f/stop = 5.6 @ 1/500s, you can
shift that program to f/stop = 11 @ 1/125s (example settings only).

I have never used the auto-ISO feature so I do not know how it would
work in P-mode.


--

Len
 >> Stay informed about: Pondering Functionality 

Wolfgang Weisselberg wrote:
> Wilba wrote:
>> Wolfgang Weisselberg wrote:
>>> Wilba wrote:
>>>> Wolfgang Weisselberg wrote:
>>>>> Wilba wrote:
>
>>>> Can you change the ISO with one touch?
>
>>> Define "one touch".
>
>> Touching one control once to effect a change. Contrast with "two touch",
>> for instance, holding down a button while turning a wheel.
>
> Then it's one touch: you press the iso-botton once, twirl the
> back wheel and there you go. No need to hold down any button.

"You press the iso-botton once" - that's the first touch. "Twirl the back
wheel", that's the second touch. Two touches.

> I guess you want to rework/expand your one-touch/two-touch with
> things like "modal control".
>
>>> Explain why "one touch" is more important to ISO than
>>> aperture/exposure/shift/comp. Explain how analog photographers
>>> survived.
>
>> The functionality I described in the original post is best supported by a
>> user interface with one touch controls.
>
> Proof?

Opinions don't need proof.
 >> Stay informed about: Pondering Functionality 

Wolfgang Weisselberg wrote:
> Wilba wrote:
>
>> The key thing in what you said is, "Depending on the camera's mode".
>> I'm suggesting in effect abandoning the conventional modes,
>
> No Tv, Av, P, M any more?

Correct.

>> and directly controlling the four parameters independently
>> at the user interface level.
>
> You cannot!
> ISO, Exposure, Aperture, compensation. That's only 3 degrees of
> freedom. Set any 3 and the 4th is necessarily derived from them.

The three independent degress of freedom are ISO, shutter speed, and
aperture. Exposure compensation is an offset applied to the ISO. I want to
be able to specify each of those four parameters directly through the user
interface, i.e. not through modes.

>> I don't want to have to remember and think my way through all the
>> information contained in your preceding seven paragraphs. I want to
>> change
>> the four parameters directly according to my whim.
>
> I want to fly by waving my hands around, according to my whim ---
> and stand a better chance of getting my wish.
>
> The correct idea is to *learn* how to use your tool --- and once
> you understand that the finger directs and the thumb corrects,
> everything is absolutely clear.

Or you make a lateral jump in your thinking about how the tool is operated,
when ancient ideas don't work so well anymore.

>> In many cases doing that won't be more or less efficient than achieving
>> the
>> same effect with conventional modes. For instance, if you want to go from
>> aperture priority to shutter priority (without any change to ISO and
>> compensation), on a conventional camera you would turn the mode dial to
>> shutter priority and set the desired shutter speed, and on mine you would
>> set the aperture to auto and set the desired shutter speed. In both cases
>> you need two touches.
>
> Aeh, how do you set your aperture to auto? Press a button?
> Or twirl the wheel from f/5.6 to f/44+ (or f/1.0 --- I have
> an f/1.4 lens on the camera by default)? The latter would be
> extraordinarily stupid, because it
> a) takes too long
> b) destroys pre-set settings

When it's time to solve that problem, you do it the best way you can find.
If you were using a wheel, pressing it in to set to auto makes sense. But
remember, that's not the problem I'm pondering.

> With Canon, if I switch from Av to Tv, I get the same setting
> for exposure as I had last time on Tv --- so I can choose usable
> presets. I only wish Canon had a few 'customer presets', so I
> could set one e.g. to ISO 1600, Tv, Comp-1, 1/60s for available
> light (or even better, a custom 3D-curve that balances between ISO,
> time and aperture in what _I_ deem as good for available light) ---
> just turn the mode wheel and there you go, all (pre)set, one touch.
>
>> I see current DSLR user interface design as being stuck on an
>> evolutionary
>> path.
>
> So are human hands. Overcomplicated, easily broken, with fingers
> that can bend just one way --- your neck can even rotate!
>
>> Now that sensitivity is as flexible as shutter speed or aperture, you
>> need
>> to define and operate 2x2x2 = 8 distinct modes (manual or automatic for
>> three parameters).
>
> Please explain why one _needs_ to define and operate 8 different
> modes.

There are three independent parameter, each of which can be set to manual or
auto - two degrees of freedom. 2^3 = 8.
 >> Stay informed about: Pondering Functionality 

Paul Furman wrote:
> Wilba wrote:
>
>> Now that sensitivity is as flexible as shutter speed or aperture, you
>> need to define and operate 2x2x2 = 8 distinct modes (manual or automatic
>> for three parameters). Rather than remember a three-dimensional matrix of
>> modes, and which user interface control does what in each mode, I want
>> to simply set the desired value for each of the four parameters, via
>> dedicated controls.
>
> What determines the auto parameter(s)?

I'm not quite sure what you mean, but I'll see if I can work it out.

> fix shutter & aperture; auto ISO
> fix shutter & ISO; auto aperture
> fix aperture & ISO; auto shutter
>
> -exposure compensation modifies the auto
>
> -leave two on auto & the camera has to guess the priority of the remaining
> two.

Let me spell out all the combinations for myself here -

Aperture Shutter ISO
Manual Manual Manual
Manual Manual Auto
Manual Auto Manual
Manual Auto Auto
Auto Auto Manual
Auto Auto Auto
Auto Manual Manual
Auto Manual Auto

Wherever any one or more of aperture, shutter speed, and ISO is set to auto,
the camera makes that decision automagically. I think of exposure
compensation as an offset to the ISO (like the way it works on my ME Super -
turning the exposure compensation dial just turns ISO dial).

> I've not even tried the P mode but isn't that supposed to let you adjust
> shutter & aperture at the wheels, alternately? Does that effectively
> switch between shutter & aperture priority? I suspect program mode is too
> clever & I wouldn't know what it's doing.

I guess it depends a bit on the camera, how it has been implemented.

> So your system would put it in manual unless one control was set
> to auto?

You tell the camera, use this value for this parameter, e.g. 1/250th, f/8,
or 100, or you tell it to make the decision for you (auto).

> And two set to auto would turn off the previous leaving the most
> recent control on auto?

Set each parameter to your choice of value, or get the camera to choose a
value for that parameter. The key thing is that they are independent in the
user interface, rather than having the function of generic UI controls
change with each "mode".

> Or like auto ISO, you'd set a trigger level for each control. ISO
> increases if the aperture is already wide open; aperture opens to keep the
> shutter above the minimum speed. Too many options to keep track of
> perhaps.

That's the camera's job, and they do that fine already, AFAICT.
 >> Stay informed about: Pondering Functionality