Google’s brand new flagship smartphone Pixel 4 comes with a variety of new and innovative camera features. Google has already said that some of those features, for example the astrophotography mode, will be made available on older Pixel devices via software updates.
However, two of the new functions will be reserved for the latest generation Pixel devices: Dual exposure controls, which let you adjust highlights and shadows via sliders in the camera app, and Live HDR+, which gives you a WYSIWYG live preview of Google’s HDR+ processing. Google confirmed this in a tweet:
Hi Mahfooz, Dual Exposure Controls and Live HDR+ require low-level capabilities in the hardware that are only available on Pixel 4, so they will not be available on older Pixel devices.
— Made by Google (@madebygoogle) October 21, 2019
According to the tweet the reason these two features won’t be available on the Pixel 3 and older devices is down to hardware rather than a marketing decision. It appears the older phones simply don’t have enough processing oomph to display the HDR+ treatment and manual adjustments in real time.