Dual Native ISO

What this is about

A dual-native camera hands the gaffer two lighting budgets. At the low base the image has maximum highlight headroom, which suits day interiors and controlled studio work. Switching to the high base at night is not digital gain: a second amplifier path takes over, so the picture can come back cleaner than it was one third of a stop below the switch. Which base a scene runs on gets fixed in prep with the DP, because it changes lamp counts, generator size and the truck.

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

Where this differs from the general case:

• The second base point is hardware, not gain — that is why it can look cleaner than the ISO just below it.
• Manufacturers publish both values per model; check the manual rather than assuming the whole camera family matches.
• The high base usually trades highlight headroom for shadow cleanliness, so day exteriors stay on the low one.

With TillyGen

In TillyGen the night scenes of a day are grouped together, so the camera stays on one base sensitivity instead of switching per setup.

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.