Just weeks after release raspberry pi camera module v3Raspberry Pi released another camera. Raspberry Pi High Quality Camera Revised for 2020.
The $50 Raspberry Pi Global Shutter Camera isn’t the successor to the High Quality camera.That camera is definitely still among us Best raspberry pi accessories list. Instead, a global shutter camera is an accessory that provides compatibility with lenses and tripod mounts, but replaces the rolling shutter used in previous cameras with a faster global shutter. The new shutter captures images and videos without rolling shutter artifacts, making it ideal for capturing fast-moving objects such as athletes in sports games or fan blades without distortion. However, you will have to accept lower resolutions than other Pi cameras.
Raspberry Pi Global Shutter Camera Specifications
| Header Cell – Column 0 | global shutter camera | high quality camera |
|---|---|---|
| sensor | Sony IMX296LQR-C | Sony IMX477 |
| sensor resolution | 1.6 megapixel | 12 megapixel |
| Maximum resolution | 1440×1080 pixels | 4056×3040 |
| shutter | global shutter | roll shutter |
| lens compatibility | C or CS mount | C or CS mount |
| size | 38×38×19.8mm | 38×38×19.8mm |
At a casual glance, the global shutter camera looks almost identical to the original high quality camera. The only thing is a plastic cover embossed with the Raspberry Pi logo. The cover is there to protect the delicate surface mount electronics from damage. Global shutter cameras use the same C/CS lenses as high quality cameras. This means you can mix and match your favorite lenses between the two lenses.
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The similarities are in sensors. The global shutter’s 1.6-megapixel Sony IMX296 sensor is no match for the Sony IMX477’s 12-megapixel. But this new camera’s pixels aren’t everything.
All past models of Raspberry Pi cameras use a rolling shutter. An array of 2D light-sensitive pixels creates values according to the amount of light they can see. These values are converted to values that the Raspberry Pi understands. The array has rows of analog-to-digital converters that send data to the Pi with a small delay per row. This delay is what causes distortion in fast moving objects in a video or image. Have you ever tried to shoot a video of a propeller or tabletop fan? Those curves splashing in the image are what the sensor “sees” as the blades pass the sensor window. For still images or slow video, this is fine. But when you want to record sporting events, scientific experiments, machine learning, etc. at high speed, you need the sharpest possible image, and that’s where the global shutter comes into play.
Global Shutter works by assigning each pixel its own analog storage element. Triggering the shutter dumps the analog value into each pixel’s storage element, where it can be read. You only get 1.6 megapixels, but resolution isn’t as important to this camera as sharpness at high speeds.
Raspberry Pi Global Shutter Camera Design
Following the design of the original high-quality camera, the Global Shutter Camera features the same metal tripod mount you’d expect to see on other models of the Raspberry Pi camera. A black plastic cover protects the circuitry from accidental shorts, something that 2020’s quality cameras didn’t have. The same four M2.5 screw holes are on the corners of his PCB and can be easily covered. A camera in a case designed for high quality cameras.
Lenses are interchangeable between the two models. This means you can reuse the various options you purchased for your High Quality camera, including those that can use Canon lenses. C-mount lenses require readily available adapters, which are cheap and easy to use.
Using the Raspberry Pi Global Shutter Camera
The software for global shutter cameras is exactly the same as these days. camera module 3There is .libcamera and Picamera2. The former is a terminal application with great features for controlling all aspects of the entire camera range (including setting the Camera Module 3’s focus system). The latter, his Picamera2, is a Python module that replicates much of the same functionality and can be easily integrated into any Python project.
In our tests, the global shutter camera has a maximum frame rate of 60 fps. I tried using the libcamera application to force the camera to record at a higher position, but each time the parameter was ignored. The only time the framerate changed was when I set the rate below 60. The global shutter camera ran fine at 30 fps. I contacted the Raspberry Pi to confirm the specs. Retest if you get an error.
Since global shutter and high quality cameras use the same lens and software, an important area to test is the claim of no rolling shutter artifacts. To benchmark this, we used the same 16mm lens at a constant height under test.
Rolling shutter artifacts are produced by fast moving objects, such as airplane propellers. Our budget doesn’t extend to hiring a plane, so a desk fan was the only option. I removed the safety cover on the fan (don’t try it at home) to maximize the chances of the camera capturing blade movement. I set the camera resolution to 1440 x 1080. This is the maximum value supported by the Sony IMX296 sensor for global shutter cameras.
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First, I captured a video using libcamera and a high quality camera. Rolling shutter artifacts were clearly present. What appeared to be dark waves crossed the spinning blades at full speed. Moving the fan (carefully) made little difference and I saw some artifacts. The same test using a global shutter camera detected little to no rolling shutter artifacts. The spinning blade was still blurry, but there was no dark wave across it.
I then moved the test to Picamera2 and configured the test to use the same resolution, then recorded video using both cameras. Again, we saw horrible rolling shutter artifacts with the high quality camera, but not with the global shutter camera.
What kind of projects is the Raspberry Pi global shutter camera suitable for?
If you need to capture fast-moving images or videos, a global shutter camera is the way to go. Sports, machine learning, and scientific experiments benefit from speed, and interchangeable lens options let you choose the right lens to capture your subject. The global shutter speed is useful for machine learning projects that need to acquire objects quickly.
A common photography project is where a global shutter camera is useless. Use a high quality camera to capture slow-moving or stationary objects. You will get better quality images.
Conclusion
Global shutter cameras have limited appeal, but for those who want that feature set, they’re welcome to come. Even if you want the best possible image quality, nothing beats a quality camera. We liked that it adheres to the mechanical standards used in high quality cameras. Being able to reuse the lens and existing tripod and armature means you don’t have to pay more.
