After something of an at-home hiatus, John Hess at Filmmaker IQ is back and he’s dropped a doozy with his new video. Have you ever wondered why the bokeh in anamorphic lenses is oval-shaped? Have you ever wondered why it’s oriented in the wrong direction relative to the de-squeeze that anamorphic footage has to go through?
Well, it’s nothing to do with the aperture, as John explains in this video. Well, put into its simplest explanation, the reason is that you’re effectively shooting two different focal lengths simultaneously when you use an anamorphic lens. One for the horizontal field of view, and a different one for the vertical.
Oh yeah, it’s a pretty weird concept to wrap your head around. But John explains it with a little bit of the maths (he doesn’t go too deep into it) and shows off some handy diagrams to illustrate the point.
And, sure, while many of the low budget “anamorphic” lens conversions do add an oval aperture to the lens to give the illusion of using an anamorphic lens, that’s nothing to do with why the bokeh is oval in a real one.