We have been poking around Steam OS 3.5 thanks to some tip-offs from the community and found some interesting updates, including HDR, saturation controls, overlay changes, and music controls.
Now, not all of these may be specific to Steam OS 3.5, some have been spotted in preview channels as well and there is no guarantee on the timeline of when and if these channels will hit the Stable channel (Stable is the default for all users)
HDR
In docked mode (the Steam Deck screen doesn't support HDR), if you have a HDR compatible screen, you can turn on HDR from the Steam Deck Display settings or the performance quick menu
Non-HDR content (such as the deck OS screens) also has a brightness control as enabling HDR mode also seems to create the effect of Auto HDR similar to that on the Series S/X Xbox consoles.
Allowing you to have the effect of HDR in games that don't have specific HDR enablement like Tales of Arise. it can be a bit aggressive and you can tune the brightness in the Advanced display settings
Overlay Changes
The performance overlay level 2 is getting a bit of an overhaul, with the battery and FPS swapping places, Gamescope becoming just FPS and the return of VRAM
Saturation
Goodbye VibrantDeck, hello built-in saturation controls, you may have seen it in the above display settings but it's also being added to the Display Quick menu under brightness
By default, the saturation is applied in the middle, which is actually an enhancement over the current stock version, which is the equivalent to turning the slider all the way to the left
The biggest enhancement for this over VibrantDeck, is these saturation levels also work while docked, so you can adjust the saturation level depending on your screen from the Deck.
Music Control
A new music control option has also appeared on the quick menu
However, this only seems to link to owned Soundtracks in your Steam library for now, hopefully, we will see some other music controls or radio added in future
One thing to note, although Decky Loader preview was updated recently as that music option has been added to the Beta and preview channels as well, it still causes a problem if you try to access the soundtracks from the menu
New Scaling Options
Nvidia Image Scaling (NIS) is now available as a deck-wide option as well as new Scaling Modes
We haven't had the chance to play with these too much but we will let you know whether these make any difference in games when we test them out.
NVIDIA Image Scaling is a driver-based feature that takes the in-game image from lower resolution and then upscales it to native resolution using a scaling algorithm and sharpening, making the output image look like it was rendered at native resolution.
We will keep our eye out for more interesting updates and if you spot any, feel free to come and say hi on our Discord server here