The PS5 is not able to display SDR, non-HDR content correctly on screen and suffers from a black crush issue.
With the PlayStation 5, Sony has chosen to make a clean sweep of the past and offer a whole new user experience for a new generation of console. This notably involves a brand new operating system, with a completely new interface. Among the changes integrated by Sony, we can mention the permanent display of an HDR stream, whether the source is HDR or not, where the Xbox for example, is content with an SDR stream (i.e. standard) when the content is not HDR.
On paper, this is a good idea from Sony, as it helps prevent black screens to turn on or off when switching to HDR on some TVs. Problem: Displaying SDR content is not ideal.
Black crush that you can’t miss
The problem is quite simple to reproduce: just turn off HDR or use the console with a classic screen. At this point, the console fails to reproduce in SDR what it is asked to display. The bug was identified by Digital Foundry teams, in particular Alexander Battaglia and John Linneman.
Yeah, it’s been a real issue for us. That said, in this case, it’s likely a full/limited RGB issue as PS5 typically crushes darker shades rather than increase the black floor.
– John Linneman (@ dark1x) March 28, 2021
John Linneman explains that the PS5 has a problem with reproducing SDR content on screen. When Digital Foundry captures an SDR game on the PS4, PS5 and Xbox consoles, it is the PS5 stream that is the only one to pose a problem, notably with “Black crush”. This means that the blacks can be displayed too deep: instead of being an area of the screen that should show a slight gray shadow, we end up with a full black that is far too strong.
In other words, even if you have a screen that shows bad HDR, it may still be better to enable this mode on PS5, since it will be better than the console’s SDR display.
A bug to fix
It is clear that Sony must correct this problem on PS5. Most, if not all, future games will be entitled to HDR processing that will go well with how the console works, but there is also a lot of historical content, especially backward compatible PS4 games, which will be problematic.