Good friend of planet5D @tylerginter sent us this very interesting article he published in his blog about the 180 Degree Shutter and what it means for shooting video and for those of you wanting more of a “film” look for your movies. The article is a really interesting read and well worth your time if you're wanting to learn more about making good movies.
A couple of excerpts from the article – and yes, you MUST read it all on his site…
“To be completely honest, before these Video DSLRs came around I didnâ€™t really understand the principles of the 180 degree shutter rule myself. Video cameras Iâ€™ve used in the past always defaulted to a 180 degree shutter automatically so unless I went into the settings to change my shutter speed or frame rate, I was always good to go! However, this all changes with Video DSLRs hitting the market because they have no preset shutter speeds to rely on and most of the manufacturers of these DSLRs donâ€™t find this rule important enough to make it a primary feature. Therefore, I figured this would be a great opportunity to consolidate a few articles and resources on the web to answer this question once and for all.”
Here's an image that may help (borrowed from Tyler's article – which he got from wikipedia)
“Anyways, letâ€™s quickly reviewâ€¦ The physical shutter in a film camera has the shape of a half circle (as you can see in the animation). This is defined as a 180 degree shutter angle, makes perfect sense since a complete circle would be 360 degreesâ€¦ In order for the film to feed through the gate while properly exposing each frame of film, the disc will have to rotate one complete revolution for every frame. Therefore if you are shooting 1fps, the frame would be exposed to the open part of the disc (allowing light to hit that specific frame of film) for only half of its complete revolution or in other words 1/2 shutter speed.”
Now that I've gotten you interested in finding out how to fix this, please read the entire article on Tyler's blog…
(Photo credit: Effect of Different Shutter Speeds (Fast Shutter to Slow Shutter from Left to Right) on Photograph by Nevit Dilmen)