One of the strengths of the OnePlus 7 Pro is represented by the photographic sector, which on the back can count on a 48-megapixel main sensor, flanked by an 8-megapixel telephoto lens and a 16-megapixel wide-angle lens.
The Chinese manufacturer advertises the telephoto lens as capable of guaranteeing a 3x zoom but it seems that, in reality, the result offered is closer to a 2.2x zoom.
OnePlus 7 Pro uses the telephoto lens horizontally but the field of view is different when using portrait mode and 3x zoom. The sensor used is a 13-megapixel Samsung S5K3M5 and the telephoto lens cuts photos up to 8 megapixels for 3x zoom and in doing so it loses the visual field.
Carl, how well does this answer apply to https://t.co/w7EVAy0cuu?
— Artem Russakovskii (@ArtemR) May 23, 2019
OnePlus advertises the telephoto lens as having a focal length of 78 mm but, given the 8 megapixel image crop, in reality the focal length is 57 mm (ie that of a 2.2x zoom).
OnePlus provided an official statement to AndroidPolice team, the manufacturer made it clear that the OnePlus 7 Pro has a 3x zoom without digital zoom or loss of details, adding that the telephoto lens has two main purposes: to offer a 3x zoom and use for portrait mode, changing the field of view according to the camera mode (with 3x zoom it offers images without loss of detail at 8 megapixels, in portrait mode all 13 megapixels are used instead).
OnePlus states that the crop being applied results in no loss of detail, as you might see from digital zoom solutions like that used by the OnePlus 5. Customers are still getting the full 8MP claimed, but not all of the zoom effect is optical.