Borja_Campillo iso is a weird number, it evolves around 19% mid gray. Since cameras are digital we can shift the mid grain by pulling or pushing digitally, which is called cine ei in alexa cameras. As you know a camera captures light lineary this is stalled in log and then previewed in rec709 like gamma 2.4. You can then decide how many stops you want below mid gray or above ny pushing the image digitally shifting the mid point. In the end its about rating the camera yourself. Edge 8k has two gain circuitries. One low and one high gain. Low gain can be as low as iso 160 high gain starts somewhere from 256p/3200 depending on how you rate tve camera (highlight stop and such)