Sony a1: what you need to know
The Alpha 1 is Sony’s new flagship camera, which it claims is a tool that can be used for sports, news, nature, portrait and commercial photography alike. To do this, Sony says it achieves a combination of resolution and speed that have previously seemed mutually exclusive.
We spoke (at some length) to Sony product experts from both the US and Japan about the a1 to dig a little bit behind the headline specs and try to address as many ‘but can it…?’ questions as possible. Here’s what we found…
New 50MP sensor
The heart of the camera and its capabilities is, unsurprisingly, its new 50MP sensor. It uses the same stacked CMOS approach as the a9 / a9 II to provide its fast readout. In addition to the DRAM built into the back of the sensor to cope with all the data being produced, Sony says the new 50MP sensor features a ‘high speed processing circuit with new analogue-to-digital method’ between the photodiodes and the DRAM at the back of the chip. Sadly they would not give any more details about this ‘secret’ technology.
Perhaps the most striking feature is the ability to read out the sensor in less than 1/200th of a second. This is 1.5x faster than the a9, despite having 1.44x more rows to read out (and twice as many pixels overall).
Sony wouldn’t directly comment on whether this is a dual-gain design, but did say that it offers ‘excellent performance in S-Log at ISO 4000’ which strongly suggests there is a second gain step.
High speed shooting and advanced stills
The headline figure is that the a1 can shoot its full 50MP resolution at up to 30 fps. Sony says this utilizes full 14-bit readout but is only available in lossy compressed Raw mode: the use of lossless or uncompressed Raw sees the capture rate drop to 20 fps.
Mechanical shutter shooting tops out at 10fps, as does shooting with A-mount lenses, using the LA-EA5 adapter.
If you want the ability to capture 30 frames per second but don’t necessarily need 50MP worth of data, the camera offers an oversampled 21MP mode that creates JPEG or HEIF images from the full 50MP data. Not coincidentally, 21MP is the same resolution as the camera offers from its APS-C crop mode, allowing for seamless switching back and forth.
HEIF images can be captured in a choice of 4:2:2 or 4:2:0 subsampling and can be shot in any of the camera’s color modes, including true 10-bit Hybrid Log Gamma, for in-camera capture for HDR displays.
Lossless Raw compression
The a1 is the first Sony camera to offer a lossless Raw compression option. As you’d expect, this promises smaller Raw files but with all the potential editing capability of the sensor’s output, which isn’t always the case with Sony’s existing, lossy compression.
The lossless compression option should provide files between 20 and 50% smaller than uncompressed files, depending on the image content. This compares favorably with the 50% reduction seen with lossy Raw compression. Moving to lossless Raw sees the maximum shooting rate drop from 30fps to 20fps but allows up to 96 images in a burst, rather than around 82 in uncompressed capture mode.
The company would not comment on whether it will be possible to extend this feature to existing models that use older processors. ‘We can’t comment on future developments, but we are listening to our customers,’ we were told.
As well as reducing the rolling shutter distortion effect in action photos, the faster e-shutter readout allows the a1 to combine electronic shutter with conventional flash at shutter speeds as high as 1/200 sec, which is faster than the sync speed of some cameras’s mechanical shutters. In APS-C/Super 35 mode, this increases to 1/300 sec.
For situations where this still isn’t sufficient (or there’s still some risk of banding in the image), the camera’s mechanical shutter can sync at up to 1/400 sec, or 1/500 sec in Super 35 mode. This is made possible thanks to a new shutter mechanism that uses both a motor and a spring to speed up the return travel.
Sony does note that these highest speeds are not available if you trigger a flash using the X-sync socket: the fastest sync requires the quicker communication possible via the camera’s Multi-shoe hotshoe.
As well as the ability to sync with flashes at up to 1/200 shutter speed, the sensor readout rate (and hence the electronic shutter rate) is sufficiently close to the speed of most conventional mechanical shutters that we’re told it can be used under artificial lighting with minimal risk of banding.
However, like a mechanical shutter, there’s still a risk that the shutter will fire during the dark part of a flickering light source’s flicker cycle. To address this, the a1 has a flicker reduction mode that syncs the shutter to the brightest point in the flicker cycle (a feature we first saw in Canon’s EOS 7D). This automatically adapts to the flicker of lights powered in either 50 or 60Hz electrical systems.
In situations where this isn’t sufficient (eg LED lighting with less predictable flicker patterns), the a1 offers a variable shutter mode in both stills and video, that let you fractionally tune the shutter speed to avoid clashing with the lights’ flickering.
The a1 promises further improvements to the already impressive subject recognition and tracking of the a9 II. The most visible change is the addition of ‘real-time’ (automatically engaged) Eye-AF for birds. As with the animal and human eye AF modes, this recognition system uses algorithms trained by machine learning: a particularly large challenge, given how small birds’ eyes can be and how diverse the appearance of different bird can be. We’ll be interested to see how it behaves when we get hold of a camera.
In addition to this, the faster readout and increased processing power means that all of these features are being implemented more quickly and more frequently. The a1 is able to perform 120 AE and AF calculations every second: twice as many as the a9 II can manage.
Sony says improved noise reduction allows the a1 to gain more usable AF information from the sensor, enabling the AF system to work down as far as f/22.
Interestingly, Sony says you can still select 759 phase-detection AF points in APS-C mode, which is the same number as is available in full-frame mode. This is only possible when using FE lenses, not APS-C-only optics, but we were given no explanation why.
The a1 uses the same 9.44M dot OLED viewfinder that we first saw in the a7S III. This offers a resolution of up to 2048 x 1536 pixels, which the camera can deliver in its 120 fps ‘High’ speed setting. A 240 fps ‘Higher’ setting is also available, which Sony says only drops to 1600 x 1200 pixel resolution. This is comparable to the maximum resolution of the 5.76M dot finder found in some other recent cameras.
The viewfinder has two modes: a full-screen mode that gives 0.9x magnification (a 41° angle of view) and 25mm eyepoint, or a ‘Zoom Out’ mode which places narrow black settings bars at the top and bottom of the display. This reduces the angle of view to 33°, but increases the eyepoint to 33mm. Zoomed-out mode is automatically engaged if the viewfinder is set to the 240 fps refresh rate.
The a1 also offers a ‘Frame Rate Low Limit’ mode, which maintains viewfinder responsiveness even when you’re shooting at slow shutter speeds. If engaged, the camera will continue to drive the viewfinder at 60 fps even when you’ve chosen a shutter speed slower than 1/60 sec. The viewfinder blacks out when an image is being taken (since it can’t offer viewfinder refresh while it’s taking a longer exposure), but makes it easier to follow action between exposures.
The fast 50MP sensor allows the a1 to become just the second consumer 8K stills/video camera we’ve encountered. Sony takes a rather different approach to Canon, reading out an 8640 x 4860 pixel region (the full width of the sensor) which is then downsampled to 7680 x 4320 8K output, promising lower levels of moiré. Noticeably this is 16:9 video, rather than the wider 1.89:1 DCI aspect ratio that Canon samples pixel for pixel.
8K video can be captured at up to 30p (or 25p for PAL users), and can be saved as 10-bit 4:2:0 XAVC HS files (H.265). HD proxy video can be captured alongside this footage, to make editing easier. The highest-quality 400 Mbps footage can be written to a V90-rated UHS-II SD card but there’s also a 200 Mbps option that can be recorded to a V60 card, so you don’t need to invest in CFexpress cards to capture 8K.
8K can also be output over HDMI but only in 8-bit 4:2:0 format.
The camera uses a similar heat dissipation design to the one developed for the a7S III. Sony says this is 5X more effective at dissipating heat than the a7R IV’s. This, in conjunction with lowering the overheat protection setting, allows for ‘more than 30 minutes’ of 8K capture. The precise figure you’ll get will depend on the ambient temperature and the bitrate you use, but we’re told recording durations significantly longer than 30 minutes are possible.
Unlike the a9 and a9 II, the a1 allows you to capture all its video with S-Log2 or 3, in true 10-bit HLG or the S-Cinetone look from Sony’s pro cameras. Sony says S-Log3 allows the capture of 15EV of dynamic range.
In terms of 4K capture, the camera can’t produce over-sampled 4K from its 8K footage, so you’ll have to do that in ‘post if you wish. Instead it offers pixel-binned 4K from the full width of its sensor at up to 60p, or up to 120p with a 1.1x crop. These can be captured as up to 10-bit 4:2:2.
4K footage can also be shot with Active Steadyshot stabilization, which adds digital correction on top of the in-body stabilization’s effect. This is not available in 8K. Information from the camera’s gyro sensors is written as metadata into the video clips, which can be used to provide more effective stabilization, during the edit.
Oversampled 4K is available in Super35 mode, which uses 5.8K capture. 4K footage can be saved with a choice of XAVCS HS (H.265) or XAVC S-I All-I (H.264) formats.
A 16-bit ~4K Raw video stream made from 4.3K capture is available in parallel with all shooting modes. We don’t have details of which recorders will work with this stream but the Atomos Ninja V saving as ProResRAW seems likely.
199MP high-resolution pixel-shift mode
As with previous Sony cameras, the a1 offers a choice of multi-shot high res modes. You have the choice of whether to shoot four frames (cancelling-out the Bayer pattern so that you’ve captured a red, green and blue pixel for every position and hence don’t need to demosaic), or a sixteen-shot mode, which does the same thing for four slightly offset positions, quadrupling the pixel count of the final image. In both cases the files need to be combined using Sony’s Imaging Edge desktop software.
The faster e-shutter mode of the a1 decreases how long it takes to shoot all these images, helping to reduce the impact of movement between frames. But it also means it’s possible to shoot high-res mode using flash, for the first time on a Sony camera. You can add a delay of up to 30 second between each capture to provide your strobes with time to recycle.
Wi-Fi and workflow
With the expectation that the a1 will be used by pros who need to deliver images quickly, Sony says it has put great emphasis on the camera’s connectivity.
As you’d expect, the a1 can be shot tethered and it offers the choice of USB, Ethernet or Wi-Fi communication.
The Wi-Fi uses dual-band 2.4 and 5GHz radios but uses MIMO (multi-in, multi-out) technology on the 5GHz band to allow FTP transfers that are 3.5x faster than the a9 II can achieve.
The a1 also becomes the first camera we’ve encountered to offer a 10Gb/s USB connection. This allows communication around 10x faster than the 1000baseT Ethernet port provided.
Body and handling
It may seem perverse to have written so much about a camera without having discussed its handling but that’s primarily because the a1 shares so much with the existing a9 II and a7S III.
The grip, dials and button layout is a match for the a7S III as, thankfully, are the better laid-out menus. As Sony’s full-frame cameras have developed over time their ergonomics have improved, and the latest menu system addresses the biggest of our remaining concerns. Sony also promises is less prone to locking you out of functions when the buffer is full: something that will is likely to be encountered more often on a 30fps, 50MP camera than the 12MP a7S III.
The good news is that the a1 allows you to make use of its touchscreen much more extensively than most previous Sony cameras. Like the a7S III you can use the touchscreen to control the menus, including the Fn menu, which immediately makes the camera quicker to use.
Unlike the a7S III, the a1 uses a tilting rear screen, rather than fully articulated panel. It features a surprisingly small and relatively low-res 3.0″, 1.44M dot LCD.
Other physical features
A lot of the camera’s other physical characteristics are carried over from the a7S III, including its ability to close its mechanical shutter to protect the sensor when the camera’s turned off: a feature Sony says pros have been asking for.
It uses the same NP-FZ100 batteries as the recent a7 and a9 cameras, from which is wrings a rating of 530 shots per charge using the rear LCD or 430 using the EVF (per CIPA standard testing). As always, we’d expect to get significantly more shots than this, especially when continuous shooting, so you can’t just divide 430 by 30 and anticipate that the camera will only shoot for just over 14 seconds!
The a1 can be powered over its USB socket using USB PD power sources, though it won’t charge the battery while it’s being used this way. It’s also compatible with the existing VG-C4EM battery grip, used by the a7S III and a9 II, which provides space for a second battery.
As with most pro-targeted camera bodies, Sony says the camera is extensively weather sealed, but doesn’t promise it’s either dust or water proof.
One aspect Sony didn’t particularly claim to improve is the camera’s image stabilization, with the specs quoting the same 5.5EV of correction we’ve become familiar with. Video stabilization can be improved, thanks to the capture of the IS gyro data for application in post-processing, but that’s the only apparent update.
It’s probably no coincidence that the companies that promise greater stabilization than this are usually the ones that have developed IS systems that synchronize the combined efforts of in-body and in-lens correction, allowing a greater degree of compensation. Sony doesn’t yet do this, instead splitting the work so that lens IS corrects pitch and yaw motion and in-body stabilization handles translational and rotational movement. This is the one area in which the a1’s spec claims fall behind those of the Canon EOS R5.
No matter how you look at it, the Sony a1 is a technically impressive camera and it has a price tag to match. However, at least on paper, it combines the speed of a sports camera with the resolution of a landscape camera, and with the features (lossless Raw compression, oversampled 10-bit 8K and fast transfers etc.) necessary to perform a wide range of roles to a level that a wide range of professionals will demand.
We’re told we can expect a camera soon, so keep an eye on our homepage for more information – and sample images – in the coming days.
Author: Go to Source