For those not familiar with Axiom Beta and the team at Apertus, see the short video explaining what their new camera is all about.
Apertus are running a crowd funding campaign aiming to raise development funds for the making of the Axiom Beta – the world’s first 4K open source camera, offering a plethora of sensor and mount option. We’ve been following their campaign closely and if you’ve missed out you can catch up on the latest developments around the Axiom Beta here and here.
Image sensors in AXIOM Beta cameras in both Super35 and 16mm versions support several HDR Modes to extend dynamic range. According to the official documentation, the CMOSIS CMV12000 (Super35) and CMV2000 (16mm version) sensors are listed as being capable of capturing up to 15 stops in High Dynamic Range (HDR) mode. Just a quick note, those sensors are off-the-shelf and CMOSIS is one of the very few manufacturers which shares documentation on the sensors; such information is vital to developers.
However initial tests show it is possible to push the sensor far beyond that. See the video below.
From Apertus: “In this video we tuned the PLR (Piecewise-Linear Response) Mode to increase dynamic range by around 6 F-stops in the highlights. To measure this, the aperture was opened/closed with a variation of 6 f-stops. While not very scientific, it is a pretty good way to obtain a ballpark estimate.
Notice the window frame manages to maintain its illumination level and how PLR only affects the clipped highlights. While not flawless, the footage shows there is a lot of potential.”
Even though the PLR settings can be pushed even further, there would always be a trade-off:
Color saturation decreases with the amount of PLR highlight recovery and the noise gets stronger in those areas. Internal camera compensation for these effects might be possible. More benchmarks and measurements are planned in the future.
Another consideration for PLR is that compressing more dynamic range into the same bit-depth actually leaves you with less bits per latitude level so PLR might not always be desirable.
The beauty of PLR though is that it can be dynamically tuned to each scene and in theory could provide more optimal results in pretty much any lighting conditions.
Here is some footage with and without PLR:
HDR mode offers some incredible benefits to shooters and we cannot await to see the finished models of the Axiom Beta in both Super35/Four Thirds and Super 16mm sensor options. The monochrome versions would offer more creative options as well and will provide a more budget alternative to the Red Epic Monochrome or even the Digital Bolex D16 Monochrome.
The Axiom Beta crowd funding campaign (link here) is in its final stages with less than 5 days left, and the guys at Apertus are very close to meeting their goal of 100,000 at 90% so every penny counts and if you like what they are doing consider supporting them.
For more details on the Axiom Beta sensors and HDR mode follow the links below.