What is HDR video?
HDR stands for High Dynamic Range, and it has been around in photography for years. Essentially, when a photographer sets the exposure for a picture, they must chose what they want to be properly exposed. The Dynamic Range is the difference between the darkest and lightest part of the picture that will retain detail. Anything above this range becomes blown out in white, and anything below becomes black. A perfect example of this effect can be seen when taking a picture in an outdoor scene. With most cameras, if the photographer exposes for the ground, the sky will be white because it is much brighter than the objects on the ground. But if the photographer exposes for the sky, the ground is far too dark and sometimes simply becomes a silhouette.
High Dynamic Range allows a photographer to expose both the sky and the ground at the same time, making the resulting image look more like the scene does for the human eye.
The camera has been set up to properly expose the scene outside.
The camera has been set up to expose the interior properly.
A frame of video shot in HDR, combining an exterior and interior exposure.
Why use HDR video?
The advantage to using HDR video is that it allows your viewers to see the scene outside and the interior of the scene at the same time. The human eye has a much wider dynamic range compared to most cameras, so we expect to be able to see both scenes at once. This technique truly becomes useful in real estate, as the view outside a window may be just as meaningful as the layout of the room.
Why is HDR more expensive?
Most video cameras are not able to capure HDR video. Our cameras have the capacity, but post processing the images is both time and resource intensive. The camera alternates between capturing a bright image and a dark one while filming. We then take each frame and render them as JPG image files. From there, special software combines the light and dark images to create an HRD frame. Finally we recombine these frames into a video. The whole process can take hours, depending on how long the shot is.
What are the limitations?
Because we are changing exposure every other frame, the video cannot contain very much motion, as any object in motion will leave a ghosting effect. Because of this, HDR video is limited to smooth panning shots which are themselves ideal for real estate.