Videography 101 – Understanding Dynamic Range
After we went over exposure and lenses and you now understand how to use each of them it is time to understand how your camera reacts to light so you can use that to your advantage.
The sensor in your camera has an ability to capture a specific amount of light values. The values range from what the sensor will consider as 100% brightness to 0% brightness which is black.
The range between what the camera will record as bright to darkness is called Dynamic range.
Different cameras have different dynamic range. The more dynamic range the camera has the more data the camera can store and the more you will be able to see the light and dark points in the video you shoot.
Here is an example. The video on the right is a video shoot with the Canon T2 that has 8 stops of dynamic range, the video on the left is a video from my Sony a6300 which Sony claims to have 14 stops of dynamic range.
If you look at the places in the video where we have a lot of light you can see that the Canon T2i video is all white and on the Sony you can still make out details.
If you try to shoot too bright spaces or too dark spaces, depending on your camera’s dynamic range, you will make your sensor blind either by giving it too much light or by giving it too little light. So the basic rule when shooting a video is that you want to try to avoid aiming the camera at places that are either too dark or too bright in the same frame.
One way to do it is using a diffusion which is easy to create, and I cover it in this DIY diffusion panel video.
The first thing you will need to do to be able to avoid it is the turn on your camera’s light meter.
That Light Meter (usually referred to as zebra stripes) will tell you when and where in your frame you have too much light. These zebra stripes will turn on in the part of the image that has a light value that surpasses the values you selected.
Adjust the light levels to your liking. I usually set main to about 90% or 95% and now when you aim your camera at an area with a light you can see if you are making the sensor go blind in that area which is referred to as “clipping the lights”.
Another useful tool is a histogram. A histogram is a measurement of the light values in the footage displayed as a graph.
On the left side we have the blacks, in the middle the mid-tones and on the right side the whites.
You want to have the histogram evenly distributed.
If your histogram is shifting too much to the left that means most of the data in the video is in the darks points, if the histogram is shifting too much to the right that means most of the data in the video is in the highlights.
The important thing to remember is that the camera has a specific tolerance between the bright areas and the dark areas and pushing it beyond that specified limit will cause the sensor to go blind and create areas in the video the are unusable.
Obviously, the more expensive cameras will record more dynamic range leaving you with more options to push the footage in the color grading process.
Understanding how to shoot your camera with the zebra lines or the histogram is one of the most important tools a camera operator can have and most times will be the main factor that will make your video look good or horrible.