Martin Munthe

Hitchcock refusing a long lens in Rear Window.

To a German filmmaker in the 1920's this would be the perspective of a small kid. To us it's just "action" and "drama". That's why you would never find this kind of shot in a Hitchcock movie.

Yes, the interocular distance between the eyes helps the brain to judge scale (750 mm being the most common). But the arctan value (distance behind the lens of your eye and it's retina) is also important for judgement of scale in the brain. If you lose an eye you are still going to be able to judge scale by that distance. A camera doesn't have periferal vision. We do. That's where the comparison between eye and camera has to end. We can only extend what a normal lens sees by adding a bigger sensor/bigger negative. It's really a very simple principle. An eye that is only 8 mm deep belongs to a small person. An eye that is 300 mm deep belongs to a very large person. If you put two 300 mm lenses at a normal interocular distance of 750 mm you will still have the feeling that the world in front of you is a miniature. The German way of making films was to view the camera as a person (the audience) or a character (pushing dramatic events either through straight POV or the "perspective"). That's why normal lenses was extremely important. You had to have a dramatic reason for turning the audience eyes small or large. You'll find this line of visual thinking in art dating back to medieval times and older. Look at how a classical painter measures reality in front of him with different tools.

Greetings. I have a historical interest and have been a fan of Hitchcock since as long as I can remember so I set out to solve this talk of "50 mm" that Hitch often dropped in conversation with journalists. Hitchcock was from the "Vienna School" of filmmaking (no that's probably not a term ). The same "school" or line of thinking that Murnau and Lang and Michael Curtiz belonged to. It has very old engineering roots. We can date it back to the lte 19th century if we like. Let's not forget that the first film cameras are primitive models of the human head. Friese-Greene built a stereoscopic film camera in around 1888 that was mounted at human eye level. That "school" followed the thinking that the focal lenght represents the physical size of the watching audience. Shot length = tiny person. Normal and then long lenses representing giants. For all of you that have done work in stereoscopy understand the principle since perspectives and size get's weird when you go out of the normal (around 50) lens zone in stereo 3D. So to confirm what Hitch was talking about - I ran some of his films through a camera solve software tool that retrieves FOV meta data. Matching that to type of camera used and voilá! Psycho, Rear Window and so on (35mm open gate) is shot 50mm all through. And his VistaVision films are all shot using the 50 mm. He did not switch lenses to match FOV. Field of View was not a priority. His VistaVision films have about 10 more degrees of viewing angle. "Shrinking the equivalent of the human eye" or the other way around was probably not even something he thought about. My guess is he picked this up from the directors and cameramen at Babelsberg/UfA. Modern films must have looked weird to that era of directors. The camera jumping from dwarf to giant for no story reason other than to fit the camera on set or for it to "look cool". We are actually talking about a part of the language of cinema we don't speak anymore. A set of primes must have been viewed as a box of different sized people. From dwarf to giant. Murnau experimented with the "effect lenses" (everything outside the normal 50) a great deal to create claustrofobia and dreams. I've chatted with a few optical engineers and the consensus seems to be that 45 mm is spot on the median human being (Angle of View not Field of View). 45 is however still an unusual focal length. I only know of IRIX having a modern 8K lens. Samyang are on their way Q2 2023.