The Exposure Triangle Is Misleading And Unnecessary.

Of course it is 🙂 Did you actually look at the title of my thread "The Exposure Triangle Is Misleading And Unnecessary."? 😊

In my op I explain why the exposure triangle is useless to me now and how I was mislead by its 'teachings' when I first got into photography. Now, whether anyone chooses to agree with me or not is their choice to make, hence the discussion in this thread.

That's nonsense because in my very op I state very clearly what exposure* is and in most of my posts' signature I include what exposure* and optimal exposure** mean to me.

All of that is described in my "Why are my photos noisy?" thread.

* 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.

When I use to shoot sporting mainly paintball events I always felt that I needed to upload that days work as soon as possible (most of the time it was 30min after the event). after about a year of doing this I looked at the log as to when the work was being downloaded I had 1 client that had done this 2 hours after the event in 1 year.
After that I was in no real hurry and looked at getting things out within 24hrs.

Even with sponsors 24 - 36 hours was about the earliest I uploaded and never had one sponsor logon 36 hours after the event in 12 years

Ignoring scene luminance, using the same aperture and exposure time yields the same exposure. ISO has no effect, whatsoever, on exposure.

ISO can be implemented differently on digital cameras.

• It can be implemented as an amplification of the pixel voltage before analogue digital conversion.
• It can be implemented as change in analogue gain, by reducing the capacitance of the pixel.
• It can simply be ignored and the data tagged to indicate 'ISO intent'

Once the raw image is processed, ISO setting may affect processing, like increasing noise reduction.

A large part of the noise in the image is coming from 'shot noise' which is random variation of light quanta reaching the pixels and that noise is only related to subject luminance and exposure.

There are other sources of noise, but that noise mostly affects the darkest part of the image. ISO settings can have a significant effect on that noise.

Best regards
Erik

Best regards
Erik

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