A new leak disputes an earlier one that claimed the Sony Xperia XZ3 will have a single 48MP camera. Instead, it will use the same dual camera module as the XZ2 Premium. That's a 19MP module with f/1.8 aperture and a 12MP module with f/1.6 aperture. There's no zoom here, the fields of view are just too similar - 25mm and 22mm respectively. The 13MP selfie camera (f/2.0) sounds like it was lifted off the Premium model too. This isn't a Premium model, however. The screen is listed as 5.7" 1,080 x 2,160px, same as the XZ2. And it will use the Snapdragon 845 chipset, making this a mid-season...
Source: https://www.gsmarena.com/alleged_specs_suggest_the_sony_xperia_xz3_will_use_xz2_premiums_dual_camera-news-32679.php