that is not what Im saying, every iso step =is a halving of the number electroner, the sensor has no knowledge of iso at all, it collects photons and the number of photons / electrons is determined by time and the light inlet.
That is an absolutely incorrect statement.
With the now-beaten-to-death exceptions of ISO 50 and HTP, ISO is entirely
a function of the sensor. As I've repeatedly attempted to explain, with increasing ISO the sensor applies increasing amounts of analog amplification, and all this happens on the sensor, well before the analog signal is digitized.
Yes, the number of photons that impinge upon the sensor is dependent upon the aperture and shutter (and, of course, the luminance of the scene as projected by the lens). But the number of electrons that reach the analog to digital converter (ADC) depends on how much analog amplification the sensor applies to the readout -- and the amount of amplification is directly set by the user (or the autoexposure system) with the ISO control.
With ISO 50, 100, and 200+HTP, the number of electrons per photon is the same. With ISO 200 (without HTP), thanks to analog amplification, twice as many electrons per photon make it to the ADC. The number of electrons per photon is doubled again with each additional stop of ISO.
(As a side note, "inbetween" ISO settings, those not powers of two times 100 or whatever the base ISO is, are again, with most camera systems, achieved by digital pushing or pulling from the nearest full-stop ISO. ISO 125 produces the same raw file as ISO 100 but with a metadata flag telling the raw processor to add 1/3 stop of digital push, and ISO 160 is really ISO 200 with 1/3 stop digital pull.)
And just, to further clarify what digital versus analog exposure adjustment means...if you were to write a computer program that translated the data in a raw file into a massive spreadsheet, divide every number in the spreadsheet by 2, and then translate from the spreadsheet back to the original raw file format, you'd do exactly the same thing that ISO 50 does. If you were to translate ISO 50, ISO 100, and ISO 200+HTP (assuming identical scenes, apertures, and shutter speeds) files each into separate spreadsheets, they'd all have the exact same numbers in them. But, if you exposed at ISO 200 (without HTP, but still keeping the shutter and aperture and everything else the same), the numbers in your spreadsheet would be twice as big...but they'd also have a higher standard deviation, indicating additional noise due to the distortion from the higher analog gain applied to the sensor readout. If you then, say, made the shutter a stop faster, the ISO 200 numbers would be back in line with the ISO 100 numbers, but you'd still have a higher standard deviation because of the additional noise from the increased analog amplification.
I really don't know how to express this any more clearly. If you still don't understand, then perhaps you should explain how you think the whole shebang actually functions, rather than just vaguely handwave about photons and electrons with unspecific and irrelevant references to Web pages that actually describe things correctly, and the opposite of what you describe.