can't you just make the new phones readings match the old phone. Set the phones side by side under your lights at 50%. should get you close enough for what we do.I have an iphone 6 and only thing i use it for is photone occasionally! The iphone 13 pro when i upgraded i got way different readings due to the enhanced light sensors working differently so i continued using the old phone just for readings! That is til @Lil Dab or someone wants to mail me there par meter to calibrate photone on my new phone!
can't you just make the new phones readings match the old phone. Set the phones side by side under your lights at 50%. should get you close enough for what we do.
@JP1 right! I love when some good old school shit comes along my Playlist.