ARRI might have already announced a 6K camera, but there is potentially a new one on the horizon.
We have now heard from multiple sources (more than just the one source from about a week ago) that a 6K camera with a Super 35mm sensor is coming sooner rather than later (an announcement could come this year). Supposedly part of the reason for the new SXT camera is not just for internal 4K/UHD, but because the electronics will be powerful enough to handle a 6K sensor. Keep in mind we don't have all the details yet, but these are pretty strong rumors from reliable sources.
They've also mentioned that the current ALEXA sensor in the SXT will be upgradeable to this new 6K sensor, which, if true, would be the first time that the sensor on an ARRI camera is upgradeable in this generation. At this point moving to a higher-res Super 35mm sensor is the right move for ARRI, even if plenty are happy with the current ALEXA and not many high-end projects are finished in 4K yet. There will come a time where major features all want 4K finishes, and they want the best quality possible, not just an upscaled 3.4K image with no room for cropping or stabilization. The ALEXA 65 will likely remain an ARRI rental only, so having an ARRI 6K Super 35mm camera that rental houses and owner/ops can actually purchase will be huge.
We don't have reliable specs yet, but this would probably be an entirely new sensor, because the pixel pitch of the current ALEV III sensor means that getting to 6K would make the sensor way too big for Super 35mm lenses. While the ALEXA 65 seems to be three ALEV III sensors put together (hence the A3X name), 6K on Super 35mm has to have much smaller pixels, as we can see with the RED DRAGON sensor.
ARRI ALEXA ALEV III Sensor
- Sensor Size: 28.17mm x 18.13mm
- Sensor Resolution: 3414 x 2198
- Pixel Size: .00825mm
ARRI ALEXA 65 A3X Sensor
- Sensor Size: 54.12mm x 25.58mm
- Sensor Resolution: 6560 x 3102
- Pixel Size: .00825mm
RED DRAGON Sensor
- Sensor Size: 30.7mm x 15.8mm
- Sensor Resolution: 6144 x 3160
- Pixel Size: .004996mm
I would expect a new ARRI sensor to have a similar pixel pitch as the DRAGON, potentially smaller if they keep the physical sensor size the same as the ALEXA. Going to this kind of resolution would be a return to what ARRI has harped on since the beginning, that oversampling is the best way to get a proper image (and something Sony also did with the F65). When you're working with 6K (and your final output is 4K), you're getting a much better image, because single sensor cameras have to interpolate colors between pixels, since each pixel can only represent one color (red, blue, or green).
The thing that has been on ARRI's side since they started producing the ALEXA is image quality. Regardless of the resolution, they've had one of the most pleasing images and have been one of the easiest cameras to work with. They've stated numerous times that they didn't want to move to higher resolutions until they could get dynamic range and colors they were happy with, but we know that was only a matter of time. Since Sony has been able to create global shutter 4K sensors with 14 stops of DR, clearly the technology is out there now.
Let's keep in mind again that none of this is official, but we have heard from multiple reliable sources. There is always the possibility that things could change well before announcement, or they could even decide to push it back and keep with their current SXT cameras for some time to come. These things can always be fluid until just before announcements, so we'll just have to wait and see. But if you were looking for ARRI to stay competitive on the resolution front, it looks like that could be happening sooner rather than later.