This does educate but does not help a beginner. A beginner shoots in an automatic mode.
I would say that a lower ISO will cause the camera to select higher exposure. Higher exposure means less noise in the image.
ISO has the same function in whichever exposure mode a photographer chooses. If the conversation shifts from, "What does ISO do?" to, "Which exposure mode should I use?" that would be my cue to have a conversation about the pros/cons of delegating exposure and ISO setting selection to the camera.
When I got into digital capture for the first time, I shot raw. But I had a lot of experience with film before that. So I'm an outlier. And all the film photographers who are going to convert to digital probably already have. So that means a beginner in photography probably just has cellphone experience. If we assume that the beginner doesn't want to shoot raw, the explanations get much simpler. We should just preface them by saying this doesn't all apply to raw.
As I said before, I think a beginner should turn off all the automation if they really want to learn how to be a good photographer. It was true in the film era, and it's truer now with instant feedback. But I'm probably in the minority there.
I agree.
Ideally, a beginner should have a good teacher that teaches him right things and has time for the student, and a beginner should be willing to learn.
In practice, none of the conditions are fulfilled in most cases.
I agree. Though I have nowhere near the technical expertise as you or the other guys doing the heavy lifting in these threads, I do teach basic photography and editing to individuals and small groups. I start my students on Manual exposure and auto ISO. Then we work on situations where they might elect to use Aperture or Shutter priority. Then we add manual ISO to the mix. I have them start in raw+jpeg and try to give them enough information and practice to make an informed choice. I am following this thread to get ideas to work into my teaching plan.
Jim, what you've described is probably one of the most significant and paradoxical things about the whole photography experience.
It's so incredibly easy to understand photography with film and a simple film camera. There is no mystery at all. Anyone can learn to get very good at it. And acquire sound, scientifically-based technique and knowledge. Yet it is very difficult to get the feedback needed, because it takes so much time in the exposure-sequence-see-results-process. And many drop out because it's hard to get the needed experience.
On the other hand, it's hard to understand photography with a digital camera. The simple truths are just not apparent. And it's very easy to be led to to erroneous conclusions and to believe falsehoods. Yet it is so easy to get feedback - both true and false.
I grew up with film. There was nothing else to use for the first 45 years of my photography journey. Starting before I was 10, I probably learned 90% of the important basics in the first few days. I was earning a living at it in my mid-teens. There was nothing difficult about it at all. And it fascinated me. lf I were 10 today I could certainly learn to use a digital camera. Probably faster than I learned to use a film camera. But actually understand photography? After becoming bored with the repetitiveness of the process, after becoming annoyed at the comparisons to "film photography" (which I would view as irrelevant), after becoming involved in the Internet turf wars of competing brands (which would be inevitable to a teenager today) I would probably become disinterested and forget about it.
That is not true. JimKasson gave you the right answer before Iliah Borg's post.
If you look through Iliah's posts you will see that even he told you that JimKasson had given you the correct answer. For some reason you did not want to accept it and kept banging on for an answer. Eventually Iliah Borg stepped with the same answer as Jim but with more detail.
In any case, the answer to your question is in the manual, as Iliah Borg mentioned to you, as well as the online user manual. It seems to me you are not a believer of RTFM 😎 and maybe prefer to be spoon fed answers.
"Auto: automatic calculation of grid zero (gray point position) and setting grid step to 1EV. The zero is located at the level that is 3 stops (8 times) lower than the maximum pixel value rounded up (ceiling) to the nearest power of 2. For example, if the maximum value of all pixels in the photo is 3000, then the nearest power of two greater than this value is 4096 and the EV0 value for this photo will be automatically set to level 512."
This is effectively what JimKasson posted even before Iliah Borg's post.
As Willie-John McBride, captain of the invincible 1974 Lions said, 'get your retaliation in first'.
I pinned a thread at the top of BQs with links to common questions, so that they could be found thereafter.
I was about 6 or 7 in preschool when I argued with the teacher that the Sun is a star. "No", she said, "the Sun is the Sun, and the stars are the stars, the Sun is not a star".
"But the Sun is a star just close to us, I read it in a book" - "No, the Sun is the Sun, and the stars are the stars" - etc.
I was put in a corner for that, although not for long.