The Google Pixel 6 Pro and Samsung Galaxy S20 Ultra share the same telephoto camera
It seems that the collaboration between Google and Samsung on the Pixel 6 series runs deeper than the Tensor SoC and the ISOCELL GN1 primary camera of both devices. Apparently, their cooperation also extends to the Pixel 6 Pro's telephoto camera, which the Pixel 6 lacks.
On Google's website, it describes the 48 MP telephoto camera as having 0.8 μm-wide pixels, an f/3.5 aperture and a 1/2.0-inch sensor size. Additionally, the company states that the camera supports 4x optical zoom and optical image stabilisation (OIS) with a 23.5° field of view (FoV). If you are familiar with recent Samsung flagships, then these specifications match those of the Galaxy S20 Ultra's telephoto camera.
Incidentally, Samsung replaced this 48 MP sensor with dual 10 MP sensors on the Galaxy S21 Ultra that delivered 3x and 10x optical zoom, respectively. Undoubtedly, the 48 MP camera is a huge upgrade over the last telephoto camera Google used in a Pixel smartphone, a 16 MP one found in the Pixel 4 XL. The same could be said for the 12.2 MP camera that the Pixel 5 used to capture 2x shots, albeit digitally.
In saying that, Google pitches the Pixel 6 Pro as its first true flagship smartphone. Equipping an expensive flagship with an old sensor that your competitor has ditched flies in the face of that claim, somewhat. Hopefully, the Pixel 6 Pro's cameras match expectations when we put through their paces.