Film is nowhere near the dynamic range if digital cameras nowadays. You can over or under a digital image by a factor of 32 and still get a useable image thoug

Film is nowhere near the dynamic range if digital cameras nowadays. You can over or under a digital image by a factor of 32 and still get a useable image though the highlights might clip or you might have noise inherent to the exposure. In fact, many modern cameras are ISO invariant, meaning that as long as you have enough light hitting the sensor, your ISO basically doesn't matter at all. And that's only for black and white film. Color film has much worse dynamic range. To put number on it, the ratio between the dimmest and brightest spot you can record is around 2^15 for a modern full frame camera. The best films will give you 2^13 from no noticeable exposure to depletion of the halides, and the worst around 2^4.