video looks flat when exported

If you're on a Mac, and also using iPhone footage, you've got two separate issues to deal with.

iPhone media on an SDR/Rec.709 timeline

The first is the footage, as Ann's link would cover. It's HLG, a form of SDR. In Premiere that must be transformed to the Rec.709 specs to be used on a normal SDR timeliine.

• Select one or more clips, right-click/Modify/Intepret Footage
• Set the Override-To option to Rec.709
• Redo all color correction on your sequence

And now it will export correctly.

Mac Display Issue

For some reason unknown outside Cupertino, when the Mac Retinas came out Apple designed their color management utility ColorSync to only use part of the standard, long-used Rec.709 standards for video display.

They display only applying a gamma transform of 1.96, which is the camera transform from the Rec.709 specs.

They do not apply the second required transform added many years ago in Bt.1886, for a display gamma of 2.4. Which all broadcast compliant Rec.709 systems utilize.

So the heart of the issue is that on Macs, the display of the Rec.709 video is different than on any standard broadcast/streaming Rec.709 display pipeline. So to understand the nature of the problem, read this following bit:

1) The file is fine, as-is, on export from Premiere Pro. It is only when playing that file through QuickTime player, or Chrome and Safari browsers on a Mac, that the file is displayed incorrectly.

2) When played on any Rec.709 compliant display system that file exported from Premiere Pro will display correctly.

3) If you modify the file to make it darker/more saturated, it will look as you expect on a Mac but on any Rec.709 compliant display it will be too dark with crushed blacks and perhaps over-saturated.

That's what we've all been dealing with for something like 4-5 years now. There isn't a fix, as you can't make a file that looks the same when displaying with two widely different gammas.

So some deliver only worried about how it looks on Apple gear, knowing it's crud outside the Apple-sphere. Or not caring.

Some deliver to the Rec.709 standard knowing it will look as expected on most non-Mac gear and let it go.

Some darken/up-saturate a wee bit trying to ride the middle ground. Which will 'show' a bit light on Macs, a bit dark on Rec.709 systems, PCs and all.

Your choice.

Neil

And it looks the same on the phone.  The other gamma lut I found is a .cube and won't open