A closer look at the mechanical shutter
Drones have become go-to tools for mapping and aerial surveys, and by now you’re probably well aware of the process: your UAV flies along a preset path at high speed, snapping photos at regular intervals and at a consistent altitude. The photos are then stitched together by clever software to form accurate maps.
In this article, we’re going to dive deeper into the underlying technology and look at a key feature that sets enterprise-grade mapping drones apart from the rest: the presence of a mechanical shutter.
A closer look at how CMOS cameras work
To understand why mechanical shutters are so important for mapping and surveying applications, it’s useful to go back a few steps and explore how cameras (and camera drones) work.
When light enters a camera, it's captured by an image sensor, which is composed of millions of tiny pixels. These pixels are made from a material called a complementary metal oxide semiconductor (CMOS). When light hits the CMOS, it creates an electrical charge that’s used to generate the image.
So how does the shutter fit in? The shutter controls how long the CMOS is exposed to light. If the shutter is open, light enters the camera and hits the CMOS. When the camera takes a picture, the shutter opens temporarily, allowing light to hit the CMOS and create an image.
What is the mechanical shutter and how does it differ from the rest?
There are several different shutter types, each of which exposes the CMOS’s pixels to light in a different manner.
Mechanical shutters work by exposing the entire frame of the image sensor to light in one go. This means every pixel represents the exact same moment in time of exposure. As we’ll see shortly, this timing is everything. It makes more sense when you think about how mechanical shutters work in contrast to electronic shutters or rolling shutters.