This is the new Huawei P20 Pro smartphone, which boasts what the manufacturers claim is the best ever smartphone camera. Actually, a combination of three sensors with individual lenses, a 40 megapixel (yes!) 1/1.7 inch colour sensor (significantly larger than the 1/2.9 sensor in the iPhone X), a 20 megapixel monochrome sensor (both these sensors are approximately equivalent to a full-frame 27mm lens) and a 8 megapixel 80mm equivalent lens for zooming.
Have you ever wondered why camera lenses produce a circular image circle (in general) but sensors are rectangular? Of course the answer is mostly historical – the format of a 35mm photo is in 3:2 aspect ratio, a ratio that people have long known to work well due to human binocular vision.
But lenses, in general, are circular. they produce an image circle, a circle that, in general, allows the 35mm sensor to just fit inside it. You don’t want your image circle much bigger than this (except for tilt-shift lenses) because that makes your lenses heavier and more expensive.
Are you the sort of person who thinks that digital photography is as unexciting as shaving? Then read on…