Raspberry Pi has just released the third version of its Raspberry Pi camera module, which comes in four variants, starting at 30 euros. For the first time, there is HDR imaging and autofocus.
The Raspberry Pi Camera Module 3 is the successor to the Camera Module 2 from 2016, but now features an 11.9 megapixel (MP) Sony sensor instead of the older model’s 8.1 MP Sony sensor. The Camera Module 3 is also available in four variants: standard FoV (Field of View), wide FoV, NoIR (infrared sensor) and infrared sensor with wide fields of view.
The standard field of vision versions are at the entry price of 30 €, and offer a wider horizontal field of vision of 66°, against 62° for module 2. The two options with wide field of vision cost a few euros of more (from 38 €), and offer a horizontal field of vision of 102 degrees. Eben Upton, Raspberry Pi manager, notes that the wide-field-of-view variants have slightly lower angular resolution than Module 2, but users benefit from new applications such as digital panning.
Motorized autofocus and HDR
But the two big new features of Camera Module 3 are motorized autofocus – rather than the fixed focus of its predecessors – and High Dynamic Range (HDR) imaging that most of us are accustomed to smartphone cameras.
Thanks to autofocus, Mod 3 can capture sharp images of objects located at a distance of about 5mm, which is a marked improvement over the “average” images that Mod 1 and 2 could take at a meter away with their prime lenses, according to Upton.
HDR is made possible by the back-illuminated Sony IMX708 sensor in Camera Module 3, which allows it to capture light and shadows like the human eye.
A new variant of the high quality camera
Upton claims HDR is the “most interesting feature” of the Module 3 and explains in detail why it is important for the new Pi camera accessory. As is the case with many smartphones, the Module 3 takes multiple photos with different exposures – normal, lower and higher – to create a higher quality image.
“For a scene with both bright and dark areas (a high dynamic range scene), there isn’t necessarily one right choice of exposure time: you’re faced with a difficult choice between exaggeration of bright areas and underexposure of dark areas.High Dynamic Range (HDR) sensors like the IMX708 tackle this problem by taking multiple simultaneous exposures with different exposure times.We can then select the exposure that best captures the detail of each region of the image, then apply a tone mapping process to compress the dynamic range of the result for display or storage,” says Upton.
The autofocus functionality builds on the IMX708’s Phase Detection Autofocus (PDAF) capabilities, but uses the Raspberry Pi’s Contrast Detection Autofocus (CDAF) algorithm in the lack of a reliable PDAF (Phase Detection Autofocus) result, according to Upton.
Raspberry Pi has also launched a new variant of the $60 high-quality camera, which features interchangeable telephoto and wide-angle lenses for both C and CS mounting standards. The new Raspberry Pi variant features a native M12 mount, eliminating the need for adapters that some customers used to connect fisheye lenses.
Only the Raspberry Pi 400 and the 2016 release version of Zero are incompatible with Camera Module 3 because they do not have CSI connectors. It also shares the board dimensions and mounting hole positions of Module 2. But it is not mechanically compatible with the camera cover for the Raspberry Pi Zero case.
On the software side, Module 3 is only supported by libcamera software and Picamera2 beta based on libcamera under Raspberry Pi OS Bullseye.
Source: “ZDNet.com”