We not too long ago put Sony’s new flagship of the Alpha sequence, the A1 by means of our lab take a look at procedures – curious to listen to how good it truly is? Then learn on …
After testing the Sony a7S III a while in the past, it was good to carry a Sony Alpha digital camera in my palms once more. I actually do just like the reasonably small bodily dimension and weight compared to different full-frame cameras just like the Panasonic S1 or S1H for instance.
Below the hood, the Sony A1 provides spectacular options (learn extra about these here), like internally recorded full-frame 8K as much as 30 fps or 4K 120fps, all in 10bit with correct LOG encoding in S-Log2 and S-Log3, and a further ProRes RAW recording chance with the exterior ATOMOS NINJA 5 recorder (see our article right here). Additionally, my pricey buddy and colleague Johnnie made a evaluate of the digital camera together with one among his particular “Johnnie signature” mini-documentaries here.
Utilizing the NVIDIA GeForce RTX3090 card with the Sony 8K H265 information
Because of NVIDIA we have now a loaner RTX3090 card at our workplace, and consider it or not, utilizing the 8K H265 information on an 8K (7680×4320) DaVinci Resolve (17.2) timeline was easy and reasonably fluid. GPU reminiscence utilization was round 10GB, with the GPU working at round 30% load. Including noise discount (3 frames temporal and spatial) after all causes a large drop of playback, however you continue to get about 8 fps with the settings depicted additional down on this article (5 stops below with noise discount) – after all, GPU load is then hovering round 90% and 16GB reminiscence is used. That is actually astonishing, as most graphic playing cards are stumbling already to playback 4K H265 information on a FullHD (1920×1080) timeline. In 8K, we’re speaking 33 megapixels of decision per body (UHD = 8.3 megapixels)! Spectacular! However now, let’s leap into the lab outcomes!
Rolling Shutter of the Sony A1
Capturing at 8K full-frame 25 frames per second, an excellent rolling shutter of 16.6ms is obtained (decrease is healthier). That’s on par with the Canon R5 for instance (which confirmed 15.5 ms in 8K DCI (17:9, which is 7% much less image top).
Taking a look at 4K full-frame recording at 25 frames per second, the rolling shutter drops considerably to eight.1ms. Clearly, some kind of pixel binning is going on right here – so will probably be attention-grabbing to see if the dynamic vary will profit from taking pictures within the downsampled 4K full-frame mode vs. 8K full body. In APS-C crop mode at 25fps, the rolling shutter is 11.1ms.
These are excellent rolling shutter values for an 8K full-frame digital camera! For comparability, the Sony FX6 (in addition to the Sony a7S III) reveals an 8.7ms rolling shutter for full-frame, 25fps UHD recording, the ARRI ALEXA Mini LF reveals 7.4ms for UHD 25fps full-frame recording.
Dynamic Vary of the Sony A1 at ISO800 utilizing inner recording
Please head over here to see how we take a look at dynamic vary. Capturing our Xyla21 chart at ISO800 utilizing the SGamut3.Cine / S-Log3 mode in 8K 25fps inner (H265) recording reveals the next waveform chart (on an 8K timeline):
12 strong stops will be recognized above the noise flooring, and a reasonably strong thirteenth cease, in addition to a faint 14th cease, are seen contained in the noise flooring.
That’s in keeping with the IMATEST end result at 8K decision (full-frame), exhibiting 11.9 stops of dynamic vary at a sign to noise ratio of two (SNR), and 13.2 stops at SNR = 1.
Additionally, within the center graph of the three diagrams above the SNR = 1 line (blue) about 1 – 1.5 extra stops are recognized by IMATEST.
Downsampled inner 4K recording
Now, let’s take a look on the downsampled 4K (UHD) full body picture of the Sony A1 taking pictures inner UHD XAVC HS:
As you’ll be able to see, taking pictures in UHD full body on the Sony A1 there appears to be some kind of downsampling taking place internally, which mixes pixels and subsequently reduces the noise, main to raised dynamic vary outcomes: 12.7 stops for SNR = 2 and 13.8 stops for SNR = 1.
Exterior 4.3K ProRes RAW recording at ISO800
Switching the Sony A1 to exterior RAW recording over HDMI, utilizing the Atomos Ninja V we’re getting a extra noisy picture, however the dynamic vary end in IMATEST (in comparison with inner 8K recording) will increase to 12.3 stops at SNR = 2 (13.3 stops at SNR = 1), see beneath. Clearly, for exterior ProRes RAW recording once more some kind of downsampling of the total sensor decision to 4328×2446 ProRes RAW is going on, thereby rising the dynamic vary outcomes on the SNR = 2 and SNR = 1 thresholds.
Sidenote: for some purpose, we couldn’t get the exterior ProRes RAW recording to work with the Sony A1 – information had been exhibiting high-quality on the Ninja V, however corrupted when performed again on the Ninja or in Premiere Professional. Earlier this week a brand new firmware for the Ninja V was launched, which solved our points. However sadly, that meant there was no time to redo the latitude take a look at in ProRes RAW. However I’m glad at the least with the assistance of my colleague Florian we had been capable of repeat the dynamic vary take a look at.
The waveform plot once more reveals strong 12 stops, additionally a reasonably strong thirteenth cease will be seen in addition to a faint 14th cease:
Additionally, the IMATEST ProRes RAW outcomes present about 2 extra stops buried within the noise flooring above the 13.3 stops SNR = 1 threshold (blue line within the center graph above).
These are actually good outcomes, representing the state-of-the-art of what’s doable with shopper 12bit A/D digital camera sensors – really surpassing the Panasonic S1H, S1, S5 for instance. The Canon R6 falls method behind in that comparability (see our lab article right here), and the Canon R5 reaches the same stage (article here) solely when taking pictures inner RAW – and this can be a very distinctive characteristic of the R5 that no different SLR model, full-frame digital camera on this worth bracket provides but. And sure, there’s after all the stunning Z CAM E2-F6 that shoots inner ZRAW – however ZRAW is one other story by itself, see our article here.
To me, the picture of the Sony A1 seems to be extra pure, much less processed than the one of many Sony a7S III (which is hampered by an excessive amount of inner noise discount that can not be turned off).
Latitude exams with the Sony A1
Latitude is the aptitude of a digital camera to retain colours and element when over- or underexposed and introduced again to reference publicity. It is vitally revealing, particularly when underexposing, how effectively the codecs maintain up and particularly, what the noise construction seems to be like.
As talked about earlier, resulting from our points with the Atomos Ninja V we weren’t capable of do the latitude take a look at in ProRes RAW, so we used inner 8K H265 recording as a substitute.
As ordinary, for our underexposure take a look at, we organized the scene by adjusting the studio gentle in order that my colleague Johnnie’s face stayed a tad beneath clipping (the crimson channel) – at F1.4 and 360° shutter angle (utilizing an 85mm T1.5 Zeiss Compact Prime). Stopping down from there in 1 cease increments we finally reached a luma worth of round 60% – that is our base publicity (for the data, it isn’t at all times precisely the 60% worth because it relies upon a bit on how code values are distributed with the respective LOG curve).
From there, we proceed to underexpose by stopping down the iris of the lens till F8 is reached, then shutter angles are lowered to permit additional decreasing the publicity. For all pictures, 8K inner SGamut3.Cine/S-Log3 at ISO800 settings had been used on the Sony A1.
Now let’s take a look on the first shot. As anticipated, the 4 stops above base publicity picture clip Johnnie’s brow (and some patches of the DSC Colour checker on the left, as do all Sony cameras with S-Log3), therefore the primary usable picture is at 3 stops above our (arbitrarily chosen) base publicity studio scene:
Not a lot to see from 2 stops over, 1 over, and so forth… so lets leap forward to the three stops underexposed scene, pushed again to base publicity:
A high-quality noise begins to seem, however all seems to be excellent – no shade shifts, no stripes throughout the picture, nothing. Excellent, let’s transfer on to 4 stops below, pushed again:
Once more, seems to be superb! So let’s see what the 5 stops below, pushed again picture reveals:
Luma and chroma noise turns into very evident within the picture, particularly within the darker elements of the picture – on the darkish aspect of Johnnie’s face for instance, or have a look at his T-shirt.
A little bit of noise discount in DaVinci Resolve (see settings beneath) does an excellent job on eradicating extreme noise and I discover the 5 stops below completely high-quality:
Now, the 6 stops underexposed picture shall be attention-grabbing, as we have now already reached the noise flooring within the shadows – Johnnie’s face is at round 60% luma at base publicity, 5 stops beneath which can be the darkish elements within the studio scene (at 5 stops below we went from 3 above base to five below = 8, plus 5 stops for the darkish elements within the picture = 13).
And right here, at 6 stops underexposure, pushed again the picture can’t be recovered anymore – massive blotches of chroma noise together with heavy luma noise corrupt the picture to an extent, that even when utilizing heavy noise discount the colours can’t be re-established:
Utilizing noise discount yields the next end result:
As will be seen above, shadows change into pink, the picture reveals heavy banding and can’t be totally recovered – recreation over.
Nonetheless, we have now to state that 8 stops of publicity latitude (3 above to five beneath) is a state-of-the-art end result for a shopper sensor, once more according to plenty of different cameras on this worth bracket and beneath, just like the Panasonic S1H, S1 and S5. A cinema digital camera with a extra subtle sensor design just like the ARRI ALEXA Mini LF (examined here) for instance reveals 10 stops of publicity latitude in our studio scene.
As anticipated, the Sony A1 reveals state-of-the-art shopper digital camera ends in the lab take a look at in all disciplines: rolling shutter, dynamic vary, and latitude, utilizing the interior codecs. This digital camera clearly reveals that outdated paradigms like the necessity for giant pixels to attain good dynamic vary are usually not true anymore. In any case, we’re speaking a few 50 megapixel sensor right here!
To me it appears reasonably clear that so long as these cameras use the present 12bit sensor learn out structure for video we can’t anticipate rather more than these outcomes. Simply on your reference, the benchmark up to now is the ARRI ALEA Mini LF which reveals about 2 stops extra within the dynamic vary and latitude self-discipline.
Have you ever already used the Sony A1? How do you just like the picture? Tell us within the feedback beneath!