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Telephoto

As is to be expected whenever Apple announces something new, a lot of shit is being flung around in the tech sphere over the iPhone 7 and 7 Plus. One particularly fun nugget is that the secondary camera lens on the 7 Plus’s dual-camera system is not, despite what Apple says, a telephoto lens. This is based on a few mixed-up notions from people who know just enough about photography to think they know a lot: namely that ‘telephoto’ is synonymous with ‘long’, and that 56mm (135 equivalence, when will this die) is ‘normal’ (and therefore not ‘long’ ‘telephoto’). 50mm was standardized on the 135 format because Oskar Barnack said so, essentially. Different versions of the story say that the 50 was based on a known cine lens design, or that glass to make the 50 was readily available, or that it was necessary to fill the new large image circle, but whatever the original motivating factor was – the original Leica I set a new standard with the 135 film format, and a new standard somewhat-longer-than-normal focal length with its Elmar 50/3.5. The idea behind normalcy is matching our eyesight. This, conveniently, tends to match up with the length of the diagonal of the imaging plane; √(24²+36²)≅43mm. 50 is already noticeably longer than this, and 56 even more so. There’s a reason 55-60mm lenses were popular as more portrait-capable ‘normals’.