In a nutshell: Raspberry Pi has released a new series of autofocus camera models for its popular single-board computers. The Raspberry Pi 3 camera module is offered in four different versions: sensitive to visible light and infrared, with a standard or wide field of view (FoV). All of them use the Sony IMX708 sensor with backlight and create 12-megapixel images (resolution 4608 x 2592 with pixels of 1.40 microns).
The original camera module was released in 2013 as the first official Raspberry Pi accessory, and later that year it was followed by an infrared-sensitive NoIR variant. The camera module 2, built on the Sony IMX219 eight-megapixel camera, was released in 2016 and has been serving the community ever since. To date, more than two million units of Camera Module 2 have been sold.
Cameras with a standard field of view provide a viewing angle of 66 degrees, and cameras with a wide field of view provide 102 degrees.
The camera module is equipped with an autofocus that can focus on objects at a distance of 5 cm to infinity. It is mainly based on phase detection autofocus, but will revert to the Pi contrast detection algorithm if the result of highly reliable phase detection autofocus is not available. All previous Raspberry Pi cameras had fixed-focus optics and a static set of lenses optimized for focusing to infinity.
As Raspberry Pi founder Ebon Upton notes, phase detection allows the autofocus algorithm to work continuously when capturing video to maintain focus as the target moves in the scene and/or the shooter moves.
The new camera module also supports high dynamic range imaging, which involves simultaneously taking photos with different exposure times and combining them into one photo that correctly exposes light and dark areas. The resulting image has a quarter of the resolution of the shot without HDR, Upton said, but in some situations the sacrifice is worth it.
The Raspberry Pi was able to stick to the $25 price for the standard field-of-view variants; the wide-field-of-view models have a more complex and expensive optical stack and thus cost $35.
The Raspberry Pi Camera Module 3 is already available from many authorized resellers.
