Shutter Speed

Here at Onyx I have the opportunity to use our Canon 7D Digital Single Lens Reflex camera for both photography and video. Video isn’t necessarily new to digital cameras, but the DSLR allows more control for users to make conscious decisions about how they want to shoot their video. To put it shortly, it’s more like a professional motion picture camera where you need to understand all of the components that it takes to get correct exposure.

That being said, a good chunk of videos I see online aren’t being shot properly on these DSLRs. What I see a lot of the time is a talented still photographer using video on a DSLR. You may wonder how I can tell they are naturally still photographers. It’s quite simple. Their shutter speed is all out of whack. Shutter speed is in my opinion the most important difference between using a camera for stills and for video.

The shutter on a camera is essentially the part of the camera that turns to allow light to hit a film plane or in a digital camera’s case, the sensor. The amount of light that reaches the plane is determined by how fast the shutter turns. In traditional film cameras, the film is exposing at 24 frames per second (fps). Films have been shot at 24 frames per second ever since inventors realized that it took 24 frames per second projected for the human eye not to see black between frames. The shutter is responsible for spinning to expose a frame, and then turn to cover a frame so that the camera can reset for the next frame. It’s a very complicated process that happens 24 times in a second. It’s happening so fast that when you look into a film camera you don’t even notice it happening.

Because the shutter covers the film plane for half of the time it takes to record 24 frames it’s said to have a speed of 1/48^th of a second. It’s also put in terms of angle. 1/48^th of a second is also known as having a shutter angle of 180˚ due to the shutter being a semi-circle shape.

So after knowing all of that, it’s safe to say that a person’s motion is best represented by 1/48^th shutter speed when shooting 24 fps. When shooting 30 fps the natural shutter speed is 1/60^th and so on and so forth. Representing natural movement is something that still photographers may not be used to. In still photography changing the shutter speed is second nature to prevent blurry subjects or to adjust to different lighting environments. There’s no motion capture aspect of still shooting. So making the switch over to video from still mode should always include one constant, 1/48^th shutter speed (when shooting 24fps.) In the case of the Canon 7D the closest shutter option it has is 1/50^th.  The difference is negligible. If someone changes the shutter speed to a higher speed such as 1/100^th it produces a choppy image. A person moving in a high shutter speed doesn’t look natural at all. High shutter speed captures more movement and has less blur. The video gives you a clearer image of how bass strings move. It got rid of the blur that would make the strings look natural. Shooting at 1/48^th gives movement just enough blur so that it looks natural but isn’t as drastic when you shoot at a lower shutter speeds such as 1/30^th of a second.

So what does all this mean for people shooting video with DSLRs? Keep your shutter speed constant. Not everyone needs a high shutter speed because not everyone is shooting Saving Private Ryan (warning Rated R footage). So many still photographers want to change the shutter speed because it’s what they’re used to, but I’m begging you not to. Especially when you’re planning to exhibit them on a theater screen.

A constant shutter speed limits your tools to correctly expose subjects “in-camera.” In really bright outdoor situations, you might be pulling your hair out over the ISOs and f-stops to get the look you want without sacrificing your aperture or shutter setting and without overexposing your image. The answer lies in putting Neutral Density filters on your lens. These cut down the light in specific increments but are also very costly and require several add-ons for your camera.

Using a DSLR to capture properly exposed video can be a task. The average DSLR user doesn’t have all of this equipment and rightfully so. It’s incredibly expensive. And that’s why I see so many videos shot with DSLRs that have obvious high shutter speeds.