ISO

What this is about

On a digital cinema camera ISO is not a film stock you load; it is a processing decision. The sensor captures what it captures — the ISO setting decides how that signal is amplified and where the dynamic range sits around middle grey. Raising ISO buys shadow visibility and spends highlight headroom; lowering it does the reverse. DPs therefore treat ISO as part of the look, set it in prep alongside the LUT, and change it consciously per scene rather than letting it drift shot by shot.

A term only helps when everyone on set means the same thing by it — so what follows is how it is used, not a dictionary definition.

What runs differently here

In planning terms, that means:

• On log and RAW cameras ISO mainly repositions dynamic range around middle grey; the sensor's sensitivity never changed.
• Doubling ISO equals one stop of exposure value — the arithmetic matches f-stops and shutter.
• Consistent ISO within a scene keeps noise texture consistent — grading can match brightness, not grain character.

With TillyGen

In the production plan night scenes carry their intended ISO and lighting level together, so gaffer and DIT prepare for the same exposure world.

Change one constraint and the consequences travel through the whole plan: affected shots are flagged, the call sheet is regenerated, and nobody keeps working from yesterday's version.