DxOMark: The Samsung Galaxy S20+'s "fake zoom" is better than the S10's optical zoom
The S20+ recorded an overall score of 118, a couple of points less than the top-spec Galaxy S20 Ultra (122), and just one more than the Galaxy Note 10+ (117). In the still photo category, the S20+ earned a score of 124, right on par with iPhone 11 Pro Max (124) and the last-gen Huawei P30 Pro (125). In the video category, the S20+ made away with a score of 100, on par with the S20 Ultra, Mate 30 Pro, and iPhone 11 Pro Max.
The S20+ is marketed with a "30x zoom", which we found out to just be almost completely digital zoom. That shows here, as the phone only earned a zoom score of 81, less than other zoom-centric phones like the Mi 10 Pro (110), Mate 30 Pro (91), and the S20 Ultra (88). Optical zoom is still better, especially at longer lengths.
Interestingly, though, the S20+'s zoom is better than the iPhone 11 Pro Max's 2x optical zoom (74) and the Galaxy S10+'s (68). This lends credence to the idea that cropping into a high-res bigger sensor delivers better results than a dedicated 2x optical zoom lens. LG, in particular, has received criticism for eschewing a telephoto lens on the LG V60 ThinQ in favor of a 64 MP main camera. That seems to have been the right decision.
As always, DxOmark's scores aren't to be considered gospel.