How can phones have HDR if their panels are 8-bit?

[itripley]

I thought all HDR displays were inherently 10-bit because all the HDR content I find (4K Blu-rays, etc.) is 10-bit but recently I just found out that there are a lot of HDR displays, like all the flagships smartphones (some exceptions are the ROG Phone II and the new OnePlus 8 Pro) and a lot of Vesa Certified DisplayHDR monitors (like my Dell S2719DC), out here that are only 8-bit. I know there are a lot of factors like brightness and contrast but I feel like color(s) is the most important thing in High Dynamic Range and I don't understand how they can be truly HDR, I'm guessing all this time these displays were all along HDAren't or HDR compatible.

[Sakkura]

This is the problem with HDR at the moment, it's not very clearly defined. But you're right, proper HDR does require a 10-bit panel. But they can use 8-bit color with dithering to attempt to fake 10-bit HDR. Or they can just try and put HDR in the spec sheet even though there's really nothing HDR about it.

 

You may want to look for compliance with a particular HDR specification to get a better idea of what kind of HDR a particular screen is actually offering.