Recently, Xiaomi introduced its flagship camera phone 12S Ultra, which became the fifth smartphone with a 1 “camera (after the Panasonic DMC-CM1, Sharp Aquos R6, Sony Xperia PRO-I and Sharp Aquos R7). And many, seeing the phrase “inch camera”, for some reason then they decided that Xiaomi fit a 25.4 mm matrix inside the smartphone, but this, of course, is not the case – and today we will arrange a small educational program about what the optical size of the matrix is and what it is eaten with. strange abracadabra like “1 / 1.73 “”, people preferred to scroll further, and now this is one of the important characteristics of the camera, and you need to understand what it means.

Let’s start with the fact that the optical size is really the diagonal of the sensor (more precisely, its active area, because the sensor still has “frames” – but they are not considered). But it’s not measured in inches. More precisely, not exactly in inches – Vidicon inches are used for this. One Vidicon inch is equal to 17.3 mm – not very similar to an inch, you see. Nevertheless, the Vidicon inch, like the usual one, is denoted by a quotation mark-paw “. And this is not a recent notion of marketers to make cameras seem larger, but a vestige of history.

Vidicon

A vidicon is a very ancient type of video camera that was actively used on television in the last century until digital video cameras appeared. And even now, vidicons are still sometimes used, for example, for high-speed video shooting – but very rarely. The vidicon was a tube inside which an image was formed. Due to the design features, the walls of the tube were quite thick, so a 1-inch (25.4 mm) vidicon made it possible to use a photoconductive target (in other words, a sensor) with a diagonal of only 17.3 mm. Such vidicons were called inch (which is logical), and the diagonal of their sensor was called the vidicon inch.

Photographers had their own sensor sizing system based on film width, but in the world of digital photography this has been almost completely superseded by Vidicon inch measurement of optical size. As a result, almost all manufacturers indicate the optical size of the camera in this strange unit. So Xiaomi is completely honest in calling the 17.3mm sensor of the Xiaomi 12S Ultra “1””.

By the way, what does abracadabra like “1 / 1.73 “” mean – this is the optical size of the Samsung GW1 or Sony IMX686. It literally means “one, divided by 1.73, Vidicon inch.” That is (17.3 / 1 .73) mm, or 10 mm. For comparison, 1/2.76″ = 17.3/2.76 mm = 6.27 mm (Samsung JN1) and 1/1.31” = 17.3/1 .31 mm = 13.2 mm (Samsung GN1) Well, now you know what to do with it, and you can watch the Xiaomi 12S Ultra camera live and with a ruler in the JerryRigEverything video:

© Oleg Lazarev. mobile phone