Luttieapple log 2 support in luttie (iphone 17 pro)
luttie's film engine now decodes apple log 2 from the iphone 17 pro: same log curve as apple log, apple's wider gamut. what changed, and how to use it.
luttie now decodes apple log 2, the log profile on the iphone 17 pro. pick it as the film engine's source and your footage converts correctly before the film stock sees it.
what apple log 2 is
apple introduced apple log 2 with the iphone 17 pro and iphone 17 pro max, the first iphones to record it.
the change is the colour gamut, not the curve. apple's own documentation describes apple log as rec.2020 primaries with an apple-defined log curve, and apple log 2 as "apple gamut" primaries with a log curve. the academy's aces transform for apple log 2 and opencolorio both use the original apple log curve with the wider primaries, taken from apple's white paper. that's what luttie does now.
what was wrong before
luttie only knew the original apple log. if you graded apple log 2 footage with the source set to apple log, the curve was right but the colours went through the wrong gamut conversion. greys stayed neutral, which is why it was easy to miss, but saturated colours shifted.
if you graded iphone 17 pro log footage in luttie before today, reopen it with the source set to apple log 2.
how to use it
- open the editor and load a frame from your footage
- in the film panel, pick a negative, then set source to apple log 2
- grade as usual: print or scan, exposure, printer lights
grading is free in the browser. to use the look in resolve, premiere, final cut or the blackmagic camera app, export it as a .cube (luttie pro). the lut then expects apple log 2 input, so apply it to the log clips directly with no other conversion before it.
apple log 2 is also in the free film simulator, so you can see a frame on every film stock at once.
what isn't covered yet
the apple log lut pack is still built for the original apple log. on apple log 2 footage its colours will be off, so build your look in the editor instead until there's an apple log 2 version.
how we checked it
apple log 2 shares apple log's curve in the engine, so only the gamut matrix is new, and the tests check that greys still land neutral through it. the gpu shader that runs the preview matches the cpu model to within half an 8-bit step, the same tolerance every other log source meets.
more on grading log: log footage · how to colour grade iphone prores log · how the film engine works