So I shot a bunch of footage in HLG3. Everything in camera was done correctly. Used my grey card for the white balance and exposure was properly set according to what it showed in camera. I put it in Premiere Pro and the whites are blown out when in camera there were no zebras showing, camera meeter was on 0.
It is what it is for the footage I've already shot. But I would like to know what happen? I've watch a few videos on youtube of people using HLG. It looks great and easy to work with. So with your help, hopefully I can fix whatever the problem is and give it another shot!
There's already a bit of discussion and various suggestions on how to handle this. This is happening because now Premiere will treat Rec. 2100 HLG footage as Rec. 2100 HLG footage, and when adding those clips to a Rec. 709 sequence, you are adding footage that has luminance values beyond that of Rec. 709 / SDR.
My suggestion is to apply the SDR conform effect to your HLG clips, or, perhaps add a track with an adjustment layer over your HLG clips with SDR conform on the adjustment.
Others (including Adobe) suggest you can override the color space of your footage to Rec 709, and you CAN do this (Right Click > Modify > Interpret Footage) but it's of my opinion that this can have some issues as well, such as inconsistencies between proxies. It's another option available to you though.