The Exposure Triangle Is Misleading And Unnecessary.

No, that is not correct at all because you cannot ignore the scene luminance when saying the same aperture and exposure time yields the same exposure*.

Scene luminance along with aperture and shutter speed affect exposure*

If you double the scene luminance while keeping aperture and shutter speed constant then you have doubled the exposure*, not kept it the same.

* exposure - amount of light that struck the sensor per unit area while the shutter was open
** optimal exposure - the maximum exposure* within dof and motion blur requirements without clipping important highlights.
*** under exposed - more exposure* could have been added with the DOF and blur constraints still being met without clipping important highlights.

I wonder what the Baud rate was back then...

Yes a beginner will be concerned about how light or dark the camera's jpeg is and I was as well when I first started.

But imo it is important that the beginner also understands the true/correct reason why the ISO 200 shot will potentially have more visible noise. It is not because of the higher ISO but because of the lower exposure*.

Hence me starting this thread explaining how I was mislead by the exposure triangle's 'teachings'.

* exposure - amount of light that struck the sensor per unit area while the shutter was open
** optimal exposure - the maximum exposure* within dof and motion blur requirements without clipping important highlights.
*** under exposed - more exposure* could have been added with the DOF and blur constraints still being met without clipping important highlights.

lets drive the final nail home.

from the manual of the pentax K1000 the largest selling film camera ever. 3,000,000 sold

extract from the user manual.

You haven't driven even the first nail anywhere yet 😂

And that image proves nothing at all 😄

there's 1 word that describes the whole process . what's the mystery "word" everyone is welcome to guess or do some extensive research.

Which process do you mean?

If you mean setting exposure*, I don't care what ISO the camera sets, after setting exposure* as I described earlier, as long as important highlights are not clipped. The image lightness is set in post when maximising the quality of the raw data.

If your aim is a nice looking jpeg sooc then yes, you should consider setting ISO to output the image lightness you want after setting the exposure*.

You don't need an 'exposure triangle' to do any of the above, hence the title of this thread "The Exposure Triangle Is Misleading And Unnecessary."

* exposure - amount of light that struck the sensor per unit area while the shutter was open
** optimal exposure - the maximum exposure* within dof and motion blur requirements without clipping important highlights.
*** under exposed - more exposure* could have been added with the DOF and blur constraints still being met without clipping important highlights.

As I recall the film cassettes were coded to provide this information automatically

Sherm

Most basic optics models treat light like a continuous fluid, which works for many phenomena, but when light is recorded, it is recorded as if it is a finite number of discrete particles, like marbles or ball-bearings. There is no natural force forcing these particles to arrive evenly; they arrive randomly in time and spatial position, but with much exposure, they get closer to being even, as ratios (the absolute differences will increase, though).

Let's say we were recording an out-of focus solid wall, where we'd expect the photon count to be the same for all pixels. Let's say we expected 9 photons on average, after 9ms. That is an average of 1 photon per millisecond, but what actually records is random pushes and lags:

             TIME->
Ideal:  0     1     2     3     4     5     6     7     8     9
Real-A: 0 1     2  3  4           5            6 7          8
Real-B: 0   1    2 3             4     5        6    7  8 9  10

Here we have the ideal arrival rate, and two samples of how the photons might arrive at two pixels in the same exposure.

Perhaps for your chosen photography, that last section of the graph to the right is "flat" and "iso-invariant-enough", but for someone who shoots very low exposures in the shade or with very warm incandescent lighting, that may be quite far from "iso-invariant".

I would use "brightness" for the amount of light coming from the scene, and exposure for the amount of light arriving at the sensor over the time that it's recording an image.

Don Cox

If you want a "lighter photo", you can just stick it in an image editor and make it lighter, or boost a slider during conversion. "More exposure" is primarily for "less noise"; not "more brightness". Brightness is a cheap parlor trick to meet human visibility requirements.

Not on any film camera that I own. During the last few years of film cameras, I think. But then, I normally loaded cassettes from bulk film, so maybe I didn't notice.
Don

Cassette DX coding started 1983.