The Raspberry Pi camera has allowed people to capture and process images, then process them using computer vision routines. There is only one camera port per Raspberry Pi port, a limitation that may pop up when delving into the computer vision world which benefits from eyes in many places at once.
While you could use multiple USB webcams, according to Raspberry Pi’s documentation, “the quality and configurability of the camera module is highly superior to a standard USB webcam.” At around $30 for an 8 megapixel sensor, the RPi camera isn’t going to break the bank, and it’s well supported ecosystem-wise. But there’s still that one-camera-per-board limitation.
One solution comes in the form of the IVPort V2 Raspberry Pi Camera Muliplexer. This device lets you switch between up to four Raspberry Pi V2 cameras with a single board, using 3 GPIO pins for control. You can also use several of these boards together with additional GPIO pins for up to 16 cameras feeding to one Pi. There’s also a less expensive dual version if you only need to use two cameras; this one only requires a single GPIO pin for operation.
As seen in the video below, if you’re using two of these in a stereoscopic arrangement, the left and right camera will only be off by a few hundredths of a second. While this will restrict some applications, for something like a multi-camera security feed where the exact time isn’t critical, it should be very useful. You can find more info on the setup at their GitHub repo.
Seller Canerdurmusoglu also offers a version compatible with the first RPi camera if you need or prefer that version.