>
I’ve been threatening to start a Raspberry Pi project ever since I bought one of the small computers during the original lockdown. While those plans never materialized, Raspberry Pi’s new Camera Module 3 could well be the spark that rekindles my DIY camera.
Raspberry Pi has made camera modules before – in fact, the first one was the company’s first official accessory back in 2013. So why would the third module convince me to complete a project? Because it’s basically a modern digital camera, with autofocus and HDR capabilities. And it could be the heart of a personalized camera that I would actually use, rather than admire on a shelf.
The Camera Module 3 is based on Sony’s IMX708 sensor, which is the same as the one found in the Oppo Find X2 smartphone. You don’t get that phone’s image processing pipeline, but this is modern hardware – and it’s the first official Raspberry Pi camera accessory with autofocus.
Yes, we’ve seen AF sensors before from third-party accessories like Arducam’s 64MP autofocus camera, but not at the impressively low price of the Camera Module 3. The standard costs just $25 / £26, but you can also buy a wide – angled version (with a 102-degree field of view, compared to the standard 66-degree FOV) for $35 / £36. The latter could be ideal for a homemade webcam.
The autofocus looks impressively snappy from the early demos (see below). This is because it uses phase-detection autofocus (PDAF), with contrast-detection AF (usually better for static subjects) providing a handy backup. It would have been quite embarrassing for Panasonic if the Raspberry Pi beat it to create a phase-detection AF camera. Fortunately, last week’s Panasonic Lumix S5II meant the camera giant got there just in time.
The Camera Module 3’s improvements aren’t just about autofocus – the overall image quality should be pretty solid and certainly better than those digicams from the 90s that have become mind-bogglingly popular again. Not only does the IMX708 have a resolution of 12 MP (apparently pixel-binned of 48 MP), but it also has larger 1.40 μm pixels than its predecessor. You can also record HD video with the full sensor area.
Even creating HDR (High Dynamic Range) images is possible if you’re willing to accept a drop to 3MP resolution. This is because the Camera Module 3 takes simultaneous exposures at different exposure times in difficult lighting and then applies tone mapping to get a better exposed result.
So that’s the brains of my camera project sorted. The Camera Module 3 is compatible with all Raspberry Pi’s except the Pi 400 or original 2016 Pi Zero, meaning I can reuse my Pi 4 Model B – optimistically bought with a HyperPixel screen to be the centerpiece of my Sonos Album Art display to be – to build a fancy new digital camera. Now it’s time to work out the camera body…
Return of the camera
The downside to the Camera Module 3’s larger sensor size (it’s a 1/2.43-inch chip versus its predecessor’s 1/4-inch sensor) is that many current cases won’t be compatible with it. For example, it will not work with the camera lid on the Raspberry Pi Zero Case.
Still, there are certainly new things in the pipeline – I’d like to see an equivalent of the Pi HQ camera bag (opens in new tab). And I could still be tempted into the ultimate project; building a custom camera around Module 3. There are a few 3D printer friendly designs available, such as the Pikon camera (opens in new tab)and of course a YouTuber by the name of Jeff Gerling (opens in new tab) has already adapted it to work with the new Module 3.
That said, the project does involve 3D printing, soldering, and a whole lot of patience that could be too much for me at this time of year. So I’ll probably wait for a ready case to arrive (maybe a version of the Naturebytes wildlife camera bag (opens in new tab) for a wildlife camera), before tackling the interface conundrum.
There are a number of ways to control the Camera Module 3, including the Picamera2 beta which is part of Raspberry Pi OS Bullseye. The latest version has autofocus support, but will no doubt require some tinkering (and browsing through Raspberry Pi’s Camera software manual (opens in new tab)) to get the camera going.
For me, it’s the autofocus and HDR powers of Module 3 that give it an edge over Raspberry Pi’s other new announcement: the new High Quality Camera module. This now supports M12 mount lenses in addition to the C-mount lenses that worked out of the box with the previous version.
Unfortunately, as appealing as building my own interchangeable-lens camera is, that module is based on the same camera hardware as before, with no autofocus. So I’ll probably stick with the Camera Module 3 and leave the 3D printing for another day – if my past Raspberry Pi projects have taught me anything, it’s to start small before getting carried away with big ideas.