Flying a drone to capture video brings a whole new perspective and a new tool for cinematography. Rolling shutter is nothing new to the world of cinematography, but understanding what causes rolling shutter and how to prevent rolling shutter will add that extra touch of quality to your cinematography video.
Global Shutter vs Rolling Shutter
First we need to visit on the difference between what a rolling shutter is and a global shutter. Most of our DSLR cameras on drones today use rolling shutter, but if you want to work with a global shutter camera, you will need to invest in a heavy lifter rig that can carry a high end camera like the ARRI Alexa.
The difference between the two types of shutters mostly show up in motion. Global shutter is a process where the sensor will turn on all the pixels to capture the image at the same time, and then after the set shutter speed time is up, the sensor will then turn off all of the pixels at the same time to then transfer all of the pixel's data at once in parallel off of the sensor. With Rolling Shutter, the sensor will start from say the top left pixel, and scan across each row to turn each pixel on to capture the image, and then after the specific shutter speed time, the sensor will then scan from say the top left pixel again and scan across each row to turn each pixel off and to transfer each pixel's data off of the sensor in series.
Image via SLRLounge
Here is a great video that explains and demonstrates how rolling shutter works.
Here is a video that we shot of lightning from the Phantom 4 drone. We slowed the video down to see each frame.
Rolling shutter is often unnoticed when the camera is not moving, but with a drone, there is always movement. So to avoid rolling shutter, we will need to make the right movements to minimize the amount of motion. The number one mistake most drone footages has is panning. Even the slightest adjustment of pan will catch the human eye, which will instantly break a good shot. The next bad pan move is how fast the pan is done. A super slow pan is ok, but can also have errors because your on the edge of stopping and starting the pan, but a lot of drone footages I have seen will have really fast pans, which will turn a clear shot into a blurry shot because of rolling shutter, and motion blur.
Here is a video that we created to give an example of how important it is to not pan your camera around.
With this new drone technology we now have the opportunity to place a camera in places that used to be hard to do, or expensive to do, and now we can capture some amazing stuff. The main lesson we wanted to leave you with is to be very light on the pan and tilt of your camera. If you need to pan and tilt, do it slow, and make sure the main object you want to stay focused on does not move at all. And do not forget to plan your shot out to minimize the amount of motion. There is a fine balance between the amount of motion you need to capture stunning shots, and to no break it with to much motion.