Sony Alpha 1. 8K, 10 bit Mirrorless Camera.

a1-1600.f1cb27a519bdb5b6ed34049a5b86e317-600x338 Sony Alpha 1. 8K, 10 bit Mirrorless Camera.
Sony Alpha 1. 8K 10 bit 4:2:0 Video makes this a very interesting camera.

Much rumoured for some time here it is, the Sony Alpha 1.

Some of the headlines are impressive to say the least:

  • Full Frame 8K 30fps recording from over sampled 8.6K recording using 10 bit 4:2:0 XAVC-HS.  200-400Mb/s. This should be possible for 30 minutes of continuous shooting.
  • 5.8K over sampled Super35mm 4K shooting mode. Wow!!
  • 4K up to  120fps, codecs including 10 bit intraframe and long GoP 16 bit raw output. EDIT: Originally I thought this would be oversampled from 8K up to 30fps, but I’m now hearing that it’s pixel binned. If that is the case there may be a lot of aliasing and moire in this mode.
  • S-Log3 and SGamut3.cine and YES it has S-Cinetone, so should be a good match for the FX6 and FX9.
  • 15+ Stops of dynamic range in both video mode and 15 stops in photo mode.
  • 5 Axis internal stabilisation. Built in motion detection gyros and image stabilisation as well as the ability to stabilise in post production with Catalyst Browse. 
  • Faster eye AF and improved AF – how the hell can it get any better?

Available March 2021 for $6,500 USD – A lot of money for a stills camera but not a lot for an 8K, 15+ stop video camera!

Screenshot-2021-01-26-at-17.32.56-1024x963 Sony Alpha 1. 8K, 10 bit Mirrorless Camera.
Sony Alpha 1 Full Frame 8K 10 bit video capable camera with over sampled super 35mm 4K and 120fps!



I think this is a camera that simply cannot be ignored, whether you shoot corporate videos or make Hollywood blockbusters. I have never been a fan of the ergonomics of a stills camera when shooting video. The Alpha 1 does not have ND filters and you will need to use an MI shoe adapter to get XLR audio in. Also the LCD screen on the back is quite small to use as an LCD finder for video. But it does have a very nice built in OLED EVF that looks to be of exceptionally high quality. There doesn’t appear to be any LUT options or dedicated log shooting mode.

But despite these missing or not quite right for video things, you cannot ignore 8K, the over sampled Full Frame 4K and oversampled Super 35mm 4K – plus 4K 120fps. All in all, this camera ticks a lot of boxes. It could be very nice for chroma key or green screen applications.

It won’t be the low light monster that either the A7SIII or FX6 are. But given recent improvements in sensor technology you can bet the low light performance won’t be terrible.

I also have to wonder what this sensor and processing could do if repackaged into a video camera body. Throw in an ND filter system, a couple of SDI outs and a proper viewfinder – as done with the A7SIII – FX6 – Could this be turned into the F55 replacement many are looking for? If it was it could end up better than a Venice. Could this become the Venice II?

With many parts of Sony now coming under the Alpha Group, for example Pro cameras in the US are now sold by the “Digital Imaging” arm of Sony, the same people behind the Alpha cameras. Could we be seeing the start of a new approach for large sensor video cameras sharing a lot more common DNA than in the past and all coming from just one part of Sony. It makes sense. If they do turn this into a video camera with all the right options and ergonomics it could be an awesome piece of kit.

But let’s just slow down for a minute. I haven’t seen any footage other than via YouTube yet, so maybe it’s not as good as the specs suggest. If the Full Frame 4K is pixel binned that particular mode might not be so good. I suspect this camera is going to be awesome! But at the same time for video shooters the FX9 and FX6 still make a lot of sense. The variable ND is a huge time saver, I’m not sure I ever want to go back to carrying a box of ND’s. Do I need 8K? Certainly no one except Sony have ever asked me for 8K – Sony use it for the CLED video walls. If I did lots and lots of green screen or other effects work it could be beneficial – we need to see how good the codec is first.

And for a lot of what I do the low light, low noise performance of the FX6 and FX9 are important. Exactly how the Alpha 1 stacks up against them remains to be seen. Plus I find LUTs and a dedicated CineEI mode makes shooting Log or Raw so much simpler than having to expose S-Log3 correctly when shooting run n gun.

So while the idea of the Alpha one excites me a lot. I really want to see what it’s like to actually work with before passing final judgement.

More information here on Alpha Universe: https://alphauniverse.com/

I’m not impressed by the video below. Lots of over exposed shots and some odd grading choices which is a bit disappointing. Hopefully these are issues with the video production rather than the camera.



What I don’t know:

It can read the sensor at Full Frame 8K and 30fps, so I assume there is a Full Frame downsampled 4K recording mode. But can it record Full Frame 4K without pixel binning/skipping faster than 30fps? Or does it have to go down to a lower sampling rate or crop to go above 30fps?

What will the quality of the 4K 120fps be like. Can the full 8K sensor be read at 120fps.

I assume the 16 bit 4.3K raw out will be a downsample from the 8.6K Full Frame readout. Again limited to 30fps perhaps, or a reduced scan mode for higher frame rates?

This is from Sony:

  • New 50.1-megapixel (approx., effective) full-frame stacked Exmor RS™ CMOS image sensor in combination with an upgraded BIONZ XR™ imaging processing engine with eight times more processing power[i]
  • Blackout- free continuous shooting at up to 30 frames per second[ii]
  • Fast sensor readout enables up to 120 AF/AE calculations per second[iii], double the speed of the Alpha 9 II, even during 30fps continuous shooting
  • Bright and large 0.64-type 9.44 million-dot (approx.) OLED Quad-XGA electronic viewfinder with the world’s first[iv] refresh rate of 240 fps
  • Silent, vibration-free electronic shutter
  • World’s first[v] anti-flicker shooting with both mechanical and electronic shutter
  • Electronic shutter flash sync[vi] up to 1/200 sec. for the first time in the Alpha™ series
  • World’s fastestv mechanical shutter flash sync up to 1/400 sec.
  • 8K 30p[vii] 10-bit 4:2:0 XAVC HS video recording with 8.6K oversampling for extraordinary detail and resolution, in addition to 4K 120p[viii] 10-bit 4:2:2 movie shooting capabilities
  • Wide dynamic range of 15 stops for stills[ix] and 15+ stops for video[x]
  • Improved Real-time Eye AF (autofocus) for humans and animals, and new Real-time Eye AF for birds[xi], as well as Real-time Tracking that automatically maintains accurate focus
  • 5-axis optical in-body image stabilization for a 5.5-step[xii] shutter speed advantage
  • S-Cinetone color matrix as seen in FX9 and FX6to deliver expressive cinematic look
  • Professional workflow support with the industry’s fastest[xiii] built-in Wi-Fi, SuperSpeed USB 10Gbps, 1000BASE-T Ethernet and more

SAN DIEGO, CA – January 26, 2021 – Sony Electronics, a global leader in imaging sensor technology and digital imaging, has announced the arrival of the groundbreaking new full-frame mirrorless Alpha 1 camera  asserting their commitment to leading the industry with a stunning combination of innovative new features.

The most technologically advanced, innovative camera that Sony has ever released, the Alpha 1 combines high-resolution and high-speed performance at a level that has never been accomplished in the world of digital cameras.  With a brand new 50.1-megapixel full-frame stacked Exmor RS™ image sensor, up to 120 AF/AE calculations per second, 8K 30p 10-bit 4:2:0 video and much more, the Alpha 1 will allow creators to capture what they’ve never been able to before.

“We are always listening to our customers, challenging the industry to bring new innovation to the market that goes far beyond their expectations.” said Neal Manowitz, deputy president for Imaging Products and Solutions Americas at Sony Electronics. “Alpha 1 breaks through all existing boundaries, setting a new bar for what creators can accomplish with a single camera. What excites us the most – more than the extensive product feature – is Alpha 1’s ability to capture that which has never been captured before. This camera unlocks a new world of creative possibilities, making the previously impossible now possible.”

The newly developed image sensor is built with integral memory and paired with an upgraded BIONZ XR imaging processing engine, making it capable of shooting 50.1-megapixel images continuously at an astounding 30fps with up to 120 AF/AE calculations per second. The Alpha 1’s shooting capabilities are further enhanced by a 9.44 million dot OLED Quad-XGA electronic viewfinder, with a refresh rate of up to 240 fps[xiv], ensuring no black out.  Additionally, for the first time in an Alpha series camera, 8K 30p 10-bit 4:2:0 video is available. The Alpha 1 is also capable of 4K 120p / 60p 10-bit 4:2:2 recording and includes S-Cinetone color. The Alpha 1 is also packed with features that support field professionals with faster workflow, including 3.5 times faster wireless FTP transfer speed[xv] and more.

Unprecedented Resolution and Speed

Continuous Shooting at Up to 30 Frames Per Second

The Alpha 1 captures moments that would otherwise be lost thanks to its high-speed performance, providing any photographer the speed they require to capture fast-moving objects. High speed readout from the 50.1-megapixel image sensor and a large buffer memory make it possible to shoot up to 155 full-frame compressed RAW images[xvi] or 165 full-frame JPEG images[xvii] at up to 30 frames per second with the electronic shutter while maintaining full AF and AE tracking performance[xviii].

300x250_xdcam_150dpi Sony Alpha 1. 8K, 10 bit Mirrorless Camera.

At an astonishing calculation speed of up to 120 AF/AE per second, the Alpha 1 can maintain focus with high accuracy even for fast moving subjects. It can automatically adjust exposure, even with sudden changes in brightness, with an AE response latency as low as 0.033 secondsii.

Advanced Electronic Viewfinder with the World’s Firstiv Refresh Rate of 240 fps

Complimenting the camera’s ability to capture images at an unprecedented speed, the Alpha 1 viewfinder features the world’s firstiv 240 fps refresh ratexiv, for a super-smooth display. The viewfinder does not black out when an exposure is made to offer an uninterrupted view and allow for seamless framing and tracking, even during continuous shooting. The 9.44 million-dot (approx.), 0.64 type Quad-XGA high-definition OLED display and refined optics deliver the highest resolution in its classiv. It also offers 0.90x[xix] viewfinder magnification, a 41° diagonal FOV, and a 25mm-high eyepoint for clear, low distortion viewing from corner to corner.

Advanced Autofocus

Sony continues to push the boundaries of autofocus technology with the introduction of the Alpha 1, which can easily track complex, fast-moving subjects with high precision. The camera features 759 phase detection points in a high-density focal plane phase-detection AF system cover approximately 92% of the image area – ensuring accuracy and unfailing focus in environments where focusing might otherwise be difficult.

Sony’s advanced Real-time Eye AF improves detection performance by 30% over the previous systemi, thanks to the powerful image processing engine, BIONZ XR. It ensures accurate, reliable detection, even when the subject’s face looks away. In addition to improved Real-time Eye AF for humans and animals, the Alpha 1 employs high-level subject recognition technology to provide Real-time Eye AF for birdsxi, a first in an Alpha series camera. Optimized algorithms ensure that tracking is maintained even if a sitting bird suddenly takes flight, or the framing suddenly changes[xx].

The Alpha 1 also features AI-based Real-time Tracking that automatically maintains accurate focus. A subject recognition algorithm uses color, pattern (brightness), and subject distance (depth) data to process spatial information in real time at high speed.

Silent, Vibration-free Electronic Shutter

High-speed readout from the new image sensor has made it possible to reduce rolling shutter by up to 1.5 times when shooting stills, compared to the Alpha 9 II. It also offers silent anti-flicker continuous shooting with an electronic shutter for the first timev in the world. The electronic shutter[xxi] operates silently, without mechanical noise, and is vibration-free. Stress-free continuous shooting is now possible even when shooting in challenging lighting situations with florescent or other flicker-prone types of artificial lighting. And for the first time in an Alpha camera, electronic shutter flash sync up to 1/200 sec[xxii] is possible. The advantages of the electronic shutter advantages can now come to life even when using flash for broadly expanded shooting versatility.

Dual Driven Shutter System for 1/400 Flash Sync

The Alpha 1 boasts the world’s fastest flash sync speedv of 1/400 sec. with mechanical shutter, making it even easier to capture dynamic action. In addition to a carbon fiber shutter curtain, the Alpha 1 features the newly developed dual driven shutter system utilizing spring and electromagnetic drive actuator, offering high durability and lightness at the same time.

High Resolution Shooting Enhancements

Even with this sensor’s high pixel count, the Alpha 1 offers high sensitivity with low noise, plus 15+ stops of dynamic range for video and 15 stops for stills, for smooth, natural gradations from shadows to highlights thanks to its cutting-edge processing system, throughout a wide ISO sensitivity range of 100-32,000 (expandable to 50-102,400, when shooting stills).

Additionally, the new camera features an evolved Pixel Shift Multi Shooting mode that composites up to 16 full-resolution images. In this mode, the camera precisely shifts the sensor in one pixel or half-pixel increments to capture 16 separate pixel-shifted images containing a total of 796.2 million pixels of data, which are then composited into a 199 million pixel (17,280 x 11,520 pixels) image using Sony’s Imaging Edge™ desktop application. With a flash sync of up to 1/200 sec. in this mode, it is ideal for photographing architecture, art or any other still life subject with a level of detail and color accuracy that is simply stunning. 

Professional Video Quality

8K High-resolution Movie Shooting

For the first time in an Alpha camera, the Alpha 1 offers 8K 30p 10-bit 4:2:0 XAVC HS recording with 8.6K oversampling for extraordinary resolution. Combined with Sony’s acclaimed autofocus technology, gradation and color reproduction performance, the Alpha 1 will help the user realize their creative vision with the finest detail. It’s 8K footage can also be used for flexible 4K editing during post-production.

Supporting Various Video Formats for Professionals

The Alpha 1 offers in-camera 4K recording at up to 120 frames per secondviii which allows the user to shoot up to 5X slow-motion video[xxiii]. In addition to supporting 10-bit 4:2:2 recording, this feature can be used with efficient Long GOP inter-frame compression or high-quality Intra (All-I) intra-frame compression.

The Alpha 1 features S-Cinetone, the same color matrix that produces the highly regarded FX9 and FX6 color and skin tones. It delivers natural mid-tones, plus soft colors and gorgeous highlights to meet a growing need for more expressive depth. The S-Log3 gamma curve makes it possible to achieve 15+ stops of dynamic range, while the S-Gamut3 and S-Gamut3.Cine color gamut settings make it easy to match Alpha 1 footage with video shot on VENICE cinema camera, FX9 and other professional cinema cameras.

Heat-dissipating Structure

A unique heat dissipating structure keeps image sensor and image processing engine temperatures within their normal operating range, preventing overheating while maintaining compact body dimensions. This makes it possible to record 8K/30p video continuously for approximately 30 minutes[xxiv].

Supporting Hand-held Shooting

A high-precision stabilization unit and gyro sensors, plus optimized image stabilization algorithms, achieve up to a 5.5-step shutter speed advantage, maximizing the quality of the high-resolution images derived from the camera’s 50.1-megapixel sensor. The Alpha 1 also features an Active Mode[xxv] that offers outstanding stabilization for handheld movie shooting. When using Sony’s desktop applications Catalyst Browse or Catalyst Prepare[xxvi] for post-production, an accurate image stabilization function is available which utilizes metadata generated by camera’s built-in gyro.

Other features that the Alpha 1 offers include; 16-bit RAW output[xxvii] to an external recorder[xxviii] via HDMI for maximum post-production flexibility, a digital audio interface has been added to the camera’s Multi Interface (MI) Shoe for clearer audio recordings from a compatible Sony external microphone, 5.8K oversampled full pixel readout without pixel binning for high-resolution 4K movies in Super 35mm mode and more.

Enhanced Workflow with Network Technologies including Connectivity to 5G Compatible Devices

The Alpha 1 has been designed and configured to support photo and video journalists and sports shooters who need to deliver stills or movies as quickly as possible with advanced connectivity options. It offers several features for fast, reliable file transfers. Industry’s fastestxiii built-in wireless LAN allows communication on 2.4 GHz and 5 GHz[xxix] bands with dual antennas to ensure reliable communications. 5 GHz includes 2×2 MIMO support (IEEE 802.11a/b/g/n/ac) offering 3.5 times faster wireless FTP transfer speed than the Alpha 9 II – a notable advantage for news and sports shooters who need to deliver with reliable speed. There is also a provided USB Type-C® connector to support fast data transfer when connected to a 5G mmWave compatible device such as Sony’s Xperia PRO and makes high-speed PC Remote (tethered) data transfer available for smooth handling of large image files. The Alpha 1 also has a built-in 1000BASE-T LAN connector for high-speed, stable data transfers, including remote shooting. FTPS (File Transfer over SSL/TLS) is supported, allowing SSL or TLS encryption for increased data security.

In addition to compressed and uncompressed RAW, the Alpha 1 includes efficient lossless compression with no quality degradation, Lossless Compressed RAW. There is also a new “Light” JPEG/HEIF image quality setting that results in smaller files than the “Standard” setting, allowing faster deliver for news and sports photographers who depend on speed. Along with a versatile range of RAW and JPEG formats, the Alpha 1 includes the HEIF (High Efficiency Image File) format for smooth 10-bit gradations that provide more realistic reproduction of skies and portrait subjects where subtle, natural gradation is essential. Images shot on the Alpha 1 can be trimmed in-camera to a desired aspect ratio, size, or position for versatile usage.

The Alpha 1 is also compatible with a variety of apps, add-ons and tools. With Imaging Edge Mobile and Imaging Edge Desktop[xxx], professionals can easily transfer RAW files and files that use lossless compression and remotely control Touch Tracking and Touch Focus for convenient AF operation. The Transfer & Tagging add-on (Ver. 1.3 or later) can automatically covert voice memos attached to image files to text captions or transfer the files to an FTP server from a mobile device. Desktop applications Catalyst Browse/Catalyst Preparexxvi allow professionals to browse and manage video clips shot by Sony’s camera. In addition, the Remote Camera Tool[xxxi] can remotely change camera settings and shoot from a computer connected via LAN cable and feature a number of refinements for the Alpha 1: faster transfer, touch response, dual slot and HEIF support, and more.

Reliable and Easy Operability

Professional users need more than just refined features and performance. They also need the reliability and durability demanded of any professional tool. The Alpha 1 has two media slots that both support UHS-I and UHS-II SDXC/SDHC cards, as well as new CFexpress Type A cards for higher overall capacity and faster read/write speeds. It also features a durable magnesium alloy chassis, long battery life with the Z-battery which can be extended using the optional VG-C4EM Vertical Grip (sold separately), an improved dust removal feature, shutter close function on power-off? to protect image sensor, plus dust and moisture resistance[xxxii] that maximizes reliability in challenging environments. It includes a durable, reliable HDMI Type-A connector, and USB PD (Power Delivery) support, allowing higher power to be supplied from an external source so that users can record for extended periods with minimal internal battery usage.

A revised menu structure provides easier navigation, and touch-responsive menu operation offers fast, more intuitive control with Touch Focus and Touch Tracking on its 3.0 type 1.44 million-dot (approx.) LCD monitor. For easy customization, a subset of the camera’s shooting settings now changes according to the selected shooting mode, making it easier than ever to use different aperture, shutter speed and other settings for shooting stills and movies.

Pricing and Availability

The Alpha 1 Full-frame Interchangeable-Lens Camera will be available in March 2021 for approximately $6,500 USD and $8,500 CAD. It will be sold at a variety of Sony’s authorized dealers throughout North America.

Exclusive stories and exciting new content shot with the new camera and Sony’s other imaging products can be found at www.alphauniverse.com, a site created to educate and inspire all fans and customers of Sony ? – Alpha brand cameras.

For detailed coverage on the new product on Alpha Universe, please visit this LINK.

The new content will also be posted directly at the Sony Photo Gallery.

For detailed product information, please visit:

Additionally, a product launch video focused on the Alpha 1 can be found at this LINK.

###

[i] Compared to the BIONZ X imaging processing engine.

[ii] “Hi+” continuous shooting mode. In focus modes other than AF-C, effective at 1/125 sec. or higher shutter speed. In AF-C mode, effective at 1/250 sec. or higher shutter speed, and the maximum continuous frame rate will depend on the shooting mode and lens used. 20 fps max. when shooting Uncompressed or Lossless compressed RAW.

[iii] At shutter speeds of 1/125 sec. or higher. The number of AF calculations will depend on the lens used.

[iv] As of January 2021, Sony survey. Among full-frame mirrorless cameras.

[v] As of January 2021, Sony survey. Among full-frame interchangeable-lens digital still cameras.

[vi] Up to 1/200 sec. Synchronization via the sync terminal is not available for electronic shutter.

[vii] [APS-C S35 Shooting] is fixed [Off] when shooting 4K 120p and 8K movies.

[viii] 10% image crop.

[ix] Sony internal tests.

[x] When recording with S-Log3. Sony internal tests.

[xi] Still images only.

[xii] CIPA standards. Pitch/yaw shake only. Planar T* FE 50mm F1.4 ZA lens. Long exposure NR off.

[xiii] As of January 2021, Sony survey. Among interchangeable-lens digital still cameras.

[xiv] Field of view is fixed at 33° and resolution is UXGA when selecting frame rate at 240 fps.

[xv] 3.5 times faster when compared against the Alpha 9 II.

[xvi] “Hi+” continuous shooting mode, compressed RAW, CFexpress Type A memory card. Sony tests.

[xvii] “Hi+” continuous shooting mode, CFexpress Type A memory card. Sony tests.

[xviii] At 20 frames per second, users can shoot up to 238 full-frame compressed RAW images or 400 full-frame JPEG images.

[xix] 50mm lens, infinity, -1m-1 diopter.

[xx] Accurate focus may not be achieved with certain subjects in certain situations.

[xxi] Shutter speed slower than 0.5 sec. cannot be set while continuous shooting. Tracking performance and max. aperture differs by settings and lenses.

[xxii] Up to 1/200 sec. Synchronization via the sync terminal is not available for electronic shutter.

[xxiii] Post-production editing and S&Q mode recording required. Data must be recorded to a CFexpress Type A memory card when the frame rate is 120 (100) fps or higher.

[xxiv] Sony internal tests with [Auto Power OFF Temp.] set to [High].

[xxv] Active Mode is not available for 8K recording.

[xxvi] Catalyst Browse™ version 2020.1 or later, Catalyst Prepare version 2020.1 or later are required.

[xxvii] 8K is not applicable.

[xxviii] Compatible recorders to be announced.

[xxix] 5 GHz communication may be restricted in some countries and regions.

[xxx] The Imaging Edge (Remote/Viewer/Edit) desktop application Ver. 3.1 or later is required for compositing. 

[xxxi] Remote Camera Tool version 2.3 or later is required.

[xxxii] Not guaranteed to be 100% dust and water resistant.

13 thoughts on “Sony Alpha 1. 8K, 10 bit Mirrorless Camera.”

    1. Compared to what? For 2 decades green screen was successfully performed using 8 bit SD. I bet there is the potential to pull a perfectly respectable key using 8K 8bit 4:2:0 that a lot of 4K 10 bit 4:2:2 might struggle to match.

        1. And what is Denver Riddle comparing it to? Does Denver Riddle realise that a Bayer sensor is only capable of creating the equivalent of 3:1:1 anyway.

          1. You claimed “It could be very nice for chroma key or green screen applications.” An experienced colorist disagrees. He has actually graded the footage himself. My own interest is HDR and Art Adams, Samuel Bilodeau and other respected authorities caution against highly compressed codecs and 4:2:0 so I would take a hard pass on this camera if I were looking to do high dynamic range 8K video as well.

  1. But what is he comparing it too? 8K 4:2:0 has double the horizontal chroma resolution of true 4K 4:2:2. But that’s only part of the story.

    8 bit 8K downsampled to 4K 10 bit will contain very similar tonal levels due to the way the interpolation will work. It might not be quite as good, but it will be close.

    Downsampled 8K 4:2:0 to 4K and you have true 4:4:4.

    FACT: NO bayer sensor can deliver better than 3:2:0 at it’s native pixel count, it’s simply impossible to divide up the pixels so that only 1/4 of the pixels do red and 1/4 do blue and get better than 1/2 chroma resolution vertically and half horizontally (4:2:0). Plus the Luma resolution never gets beyond 70-75% of the pixel count so the best you can expect is the equivalent of 3:2:0.

    FACT: Take 8K 3:2:0 and downsample that by a factor of two horizontally and by a factor of 2 vertically and you end up with a full luma and chroma sample at every point in the image – 4:4:4.

    Because of this a camera with a4K bayer sensor (which in reality is only really 3:2:0) will struggle to achieve even half of the chroma resolution of an 8K 4:2:0 source.

    And which highly compressed codec as there are VAST differences between different codecs. H265 is between 2 and 5 times more efficient than H264. 300Mb/s H265 can deliver the same image quality as 1Gb/s H264. And as you go up in resolution codecs become much more efficient because there is less difference between adjacent pixels.

    Can you share a link to a chroma key test with this camera?

  2. I can’t answer your question because I am not a professional colorist. In this video, Denver Riddle says you want 4:2:2 for keying or HSL secondary qualifications that demand precision. (starting at 1:00)

    https://youtu.be/yIfKtdm4u2I

    My own interest is HDR, and authorities are fairly unanimous in warning against highly compressed codecs and 4:2:0 for high dynamic range video. I also wonder whether the HDR PQ footage from the a1 is green like it is with my a7s III.

    1. But that’s like saying you need a 10 gallon bucket to wash a car. Like a 10 gallon bucket, 4:2:2 is a container. It’s not the bucket or container that matters, it’s what’s in it. 5 gallons of water is still 5 gallons, even if it’s in a 10 gallon bucket. Putting the more or less equivalent of 3:2:0 that a normal bayer sensor delivers into a 4:2:2 container doesn’t make it 4:2:2. But take the more or less 8K 4:2:0 and put that in a 4K 4:4:4 container and you really do have 4K 4:4:4.

  3. Alistair you said above ‘Downsampled 8K 4:2:0 to 4K and you have true 4:4:4.’

    Can you please explain how this happens in a bit more detail? And by what process do you mean downsampled – dropped into a 4k timeline in resolve for example or by transcoding to something?

    1. 4:2:0 in essence means you have a colour sample every other pixel on every other line, so in every 2×2 block of luma pixels there is 1 colour sample. When you take an 8K image and convert it to 4K you will combine 2×2 blocks to create one new pixel. Every 2×2 pixel group will have a colour sample, so every resulting new pixel will have a colour sample, so every point in the resulting 4K image will have a corresponding colour sample, so it is 4:4:4.

      1. Thank you. If I take the native 8k 4.2.0 file from the A1 and want to transcode it into a better format for resolve to get to 4:4:4 , would I need to set the output to scale into Prores 4444 ?

    1. My reply was aimed at Den.

      But I would also ask if this experienced colourist cautions against every Bayer camera then? After all a bayer sensor can’t deliver 4:4:4, you are lucky if you get the equivalent of 3:2:0, don’t forget Green is only sampled every other pixel and red and blue every other pixel on every other line. There is no way this can ever be the equivalent of 4:4:4, it’s closer to 4:2:0 than anything else.

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