As i learned from your earlier explanation ISO value is just a number to show how much gain is used to brighten the exposure for a proper view (on a screen in most cases).
I hope you didn't learn that from me. One of the points I try to make is that 'ISO' intrinsically has nothing to do with 'gain'. That's one of the misnomers that leads to confusion. Digital still photography was derived from video, and in video there was 'gain' control, that changed the 'gain' of the amplifier driving the cathode ray tube, making the viewed image brighter, so video engineers came to calling the 'brightness' control 'gain'. However, ISO isn't that. The problem with the poor terminology is it leads people to believe that 'signal' is being 'gained' and that signal represents 'light'. The output of a camera is grey scale or 'lightness' and has no link to an absolute amount of light at all. So the exposure isn't being 'brightened', and gain isn't being used to do it. The 'brightening' term was introduced by gollywop, who is a fine and knowledgable fellow, but has the unfortunate consequence of engendering the fallacy described above.
In brief, the output is 'lightness', an exposure has no lightness, the processing of a raw file to a viewable output involves assigning lightness values to measured exposures at the sensor and that process doesn't require 'gain'.
Exposure is only related to time and aperture.
And scene luminance, and also transmission of the lens, including any ND filters.
So if i can manual lower iso value after the exposure, picture is taken , say 3 stops until it's in base "iso" and saves that rawfile manual ,but it showes a proper bright preview on my camera lcd to examen my scene, i can later in a raw developer corrected with 3 stops , and it wil be the same jpeg as the " normal" rawfile or better because the software has a better noisereduction.
Sorry, I'm not following what you're proposing there. You can't change the effects of the ISO control on the raw file after exposure. You can process as you like and assign any set of lightness values to the measured exposures in the raw file.
So if i follow you correct just lose the ISO adjustment, like i-ISO doesn't shows you which ISO value it has chosen only a preview of a rawfile you get when pushing the button.
What I'm proposing is this. A mirrorless camera is monitoring the sensor output all the time up to the exposure, since it is using that output to drive the VF. It can make an assessment therefore of the exposure at the sensor, and adjust the voltage gain (and other capture parameters) to best capture that range of exposures. It can do that without reference to 'ISO' since ISO doesn't change the exposure at the sensor, only changing the light coming from the scene or the aperture or shutter speed does that.
i have set my g80 on max iso 6400 and i-ISO.
This way i only have to think about Aperture and shuttertime.
As I understand it, 'iISO' increases ISO when subject movement is detected, which seems a bit back to front. The aim of raising ISO is to raise shutter speed, why not directly raise shutter speed?
Aperture for DoF and when shuttertime is important switch to S prio.
What when they are both important?
or use -EV for influence the shuttertime and correct later in post.
I think auto modes get needlessly complicated. Why not just set the aperture and shutter speed you want directly?
A noisy shot is better then no shot at al , so why bother to think to be better judge then the i-ISO modes?
Because you know your own acceptance thresholds and iISO doesn't.
helps me to avoid fxckups do wrong decicions.
