Rumour has it the 64-megapixel telephoto sensor on the upcoming Samsung Galaxy S20 and S20+ won't be used for pixel-binned 4-in-1 16-megapixel photos. And that it'll offer 8K video support, likely at 8K@30fps. The Galaxy S20 and S20+ rumoured specs sheet claims the two phones will offer 3x optical zoom and up to 30x digital zoom. And it seems the zoom will be of the lossless variety as it'll crop actual pixels from the sensor. These are all speculation for now, unfortunately. So, information might come out differently when the flagships launch next month. 

Source: GSMArena