180° DEGREE RULE (for regulate the shutter speed) With the rise of digital cinema it is critical to get the classical film look. We use a lot of tools for obtain the film look, and in digital post production we can do a lot of corrections; however, during the production, we often underestimate the ancient rule of 180° degree shutter speed. How does the shutter speed influence your film/image? If you are a professional photographer you don’t need any explanation; but this is a critical point for understand why we have to use a specific value of shutter speed. I try to explain briefly: if you take a photo at a low shutter speed (for example half a second or a second) of an object in movement you get a lot of motion blur, on the contrary if you use a very fast shutter speed (for example 1/8000 sec.) you stop the object, you get stop motion. But keep in mind that in a movie there is no perfect movement: movement it is an illusion created by a series of fixed images one after another, and in the classic hollywood movie the number of fixed images that you see in a second are 24. So these 24 images put one after another are enough to create the magic illusion of the real life (which is not real life anymore, but a potential means for creating an artwork). In a traditional film camera, the physical shutter has the shape of a half circle (as to say 180° degree shutter angle, because a complete circle is 360°) This half circle rotate making one complete revolution of 360° for every single frame, so if you are shooting 1 frame per second (fps), the frame would be exposed only when is not covered by the half circle ( it is just when the frame it is not covered that the light can hit it) so it will be hit be the light just for half of a second. In a traditional film camera, during the other half of a second (when the frame it is not hit by light ) the the next frame of film moves on ready to be exposed by light, and so on for 24 times each second. Just for make things simple weve made the example at 1fps and now we know that the shutter speed would be half a second, so using a digital camera at 24 fps, the shutter speed must be 1/48 of a second.
Posted on: Fri, 04 Jul 2014 09:59:22 +0000
Trending Topics
Recently Viewed Topics
© 2015