On 2018-06-14 19:48, Jim-P wrote:
In film cameras, ISO referrs to the sensitivity to light of the emulsion.
Manufacturers formulate different film emulsions with different
sensitivites tarding increased grain with increased ISO speed.

In a digital camera, presumably the sensor does not adjust itself to have
greater sensitivity. Or does it?

So what is happening in a digital camera when I choose a greater ISO
setting? Is more amplification being used?

Yes, the analog amplifier before the analog to digital converter changes
its gain. Like the volume control in a radio.

Cameras may also add digital multiplication at the end of the range.
This means that values can go 10, 10, 20... skipping intermediate
values. Or even more noise.

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Cheers, Carlos.