Proving that speed, resolution, and video capabilities can all coexist, the Alpha a7R IIIA Mirrorless Digital Camera from Sony is a versatile, high-performance camera characterized by not only its resolution, but by its multimedia versatility. Revolving around a full-frame 42.4MP Exmor R BSI CMOS sensor and updated BIONZ X image processor, the a7R IIIA affords an impressive 10 fps continuous shooting rate along with improved autofocus performance for faster, more reliable subject tracking along with wide frame coverage. This updated Fast Hybrid AF System employs a combination of 399 phase-detection points and 425 contrast-detection areas for quicker acquirement of focus in a variety of lighting conditions, and also maintains focus on subjects more effectively. In addition to speed and AF, the processing improvements also help to realize greater image clarity throughout the sensitivity range from ISO 100-32000, which can further be expanded to ISO 50-102400. Video recording capabilities have also been extended for enhanced quality when recording UHD 4K video with the full width of the full-frame sensor, or when using a Super35 area and 5K oversampling to minimize moiré and aliasing. Additionally, benefitting both stills and video operation, the a7R IIIA retains the 5-axis SteadyShot INSIDE sensor-shift image stabilization, which is now effective to minimize the appearance of camera shake by up to 5.5 stops.
In addition to imaging updates, the a7R IIIA also sports a revised body design, which includes a 3.69m-dot Tru-Finder OLED electronic viewfinder for bright, clear, and realistic eye-level monitoring. An updated rear 3.0" 2.36m-dot tilting touchscreen LCD is also available for intuitive settings control and to better support working from high and low angles. For greater shooting flexibility, dual SD memory card slots are now featured, and a larger NP-FZ100 battery is also employed to achieve up to approximately 530 shots per charge when using the viewfinder. Suiting the camera's use in trying conditions, the magnesium alloy chassis and extensive weather-sealing also render the a7R IIIA dust- and moisture-resistance
a7R IIIA Improvements
Compared to its predecessor the a7R III, the most significant improvement of the a7R IIIA is the rear LCD resolution, which jumps from 1,440,000 to 2,359,296 dots. The USB port has also been upgraded from a USB 3.1 Gen 1 Type-C Port to a faster USB 3.2 Gen 1 Type-C Port. Beside these two improvements, the a7R III and a7R IIIA are equal in specifications and performance.
42.4 MP Exmor R BSI CMOS Sensor and BIONZ X Image Processor
Featuring a back-illuminated design, the full-frame 42.4-megapixel Exmor R CMOS sensor works with the BIONZ X image processor to offer high-resolution stills and video while minimizing noise and improving speed. This sensor structure works with gapless on-chip lens design and an anti-reflection coating, as well as eliminating the optical low-pass filter, to improve light collection and enhance detail. Also, the copper wiring layer dramatically improves data transmission speed for creating 14-bit, high-resolution 42.4-megapixel stills with a native sensitivity range from ISO 100-32000, which can be further expanded to ISO 50-102400. Also, it enables internal UHD 4K video recording with a wide dynamic range using the full width of the full-frame sensor. The BIONZ X processor also works in conjunction with a high-speed front-end LSI to realize faster processing times along with the ability to capture an impressive 15-stop dynamic range at low sensitivity values.
The sensor and processor combination also avails fast continuous shooting at up to 10 fps at full resolution, for up to 76 consecutive frames, and with full-time AF/AE when working with either a mechanical shutter or an electronic shutter. If shooting in live view mode, a continuous shooting rate of up to 8 fps is also possible.
Fast Hybrid AF System
An evolved 4D FOCUS system now employs a combination of 399 phase-detection points, which cover approximately 68% of the frame, along with 425 contrast-detection areas for reliable and quick autofocus and subject tracking performance. This Fast Hybrid AF System now achieves twice the focusing speed and more reliable tracking compared to previous a7R models, as well as improved low-light focusing response down to -3 EV. The use of phase-detection points also enables the use of A-mount lenses via the optional LA-EA3 or LA-EA1 lens mount adapters with full continuous AF/AE tracking compatibility.
The apt focus system also lends itself to a variety of focusing functions for refined accuracy, including Lock-on AF, which maintains focus on moving subjects throughout the use of a configurable frame that is set over the desired moving subject, and Expand Flexible Spot, which employs neighboring focus points to retain focus on moving subjects even if the originally selected point loses focus. Additionally, Eye AF can be used to base focus on recognized subjects' eyes for portraits and is available in both AF-S and AF-C modes. Autofocus can also be used in conjunction with the Focus Magnifier function for critical focus when homing in on minute subject details. The rear touchscreen can also be used for Touch Focus control, and a Touchpad Focus Control mode lets you use the rear screen intuitively while keeping your eye to the viewfinder.
For more personalized control over focus, and benefitting working in either vertical or horizontal shooting orientation, the AF area can be switched in orientation to better suit your subject matter. AF tracking sensitivity can also be customized in five steps to match how a subject is moving and frequently used focus point settings can be memorized and recalled with a custom button for faster switching between focus settings.
5-Axis SteadyShot INSIDE Image Stabilization
Packed into the robust a7R IIIA is a 5.5-stop effective 5-axis SteadyShot INSIDE image stabilization system that compensates for five different types of camera shake encountered during handheld shooting of stills and video. This allows users to confidently use any lens, even adapted lenses, for critical imaging without encountering blur from camera shake.
For long focal lengths, the system will correct for pitch and yaw adjustments. Macro and high-magnification imagery, on the other hand, will benefit from the inclusion of horizontal and vertical shift compensation. All shooting styles will get usage out of the roll compensation. All 5 axes of stabilization will function at all times, even when used with third-party lenses and adapters or lenses with built-in optical stabilization.
UHD 4K Video Recording in XAVC S Format
Internal recording of UHD 4K movies is possible in multiple frame rates up to 30 fps and, based on the Super35mm recording area and effective 5K resolution, oversampling renders greater detail and full pixel readout is possible, that is void of pixel binning, for higher quality imagery with reduced moiré and aliasing. Full-frame 4K recording has also been dramatically improved for improved quality when working at mid to high sensitivities to permit full use of the entire sensor width. Full HD 1080p recording is also supported in frame rates up to 120 fps, and both resolutions utilize the 100 Mbps XAVC S format contained within an MP4 wrapper with 4:2:0 sampling. The high-speed, 120 fps recording also enables 4x and 5x slow-motion movie recording with the frame rate set to either 30p or 24p. In addition to high-resolution internal recording, uncompressed HDMI output also enables the use of an optional external recorder for clean 4K recording with 4:2:2 sampling.
4K video recording also avails the ability to produce 8MP stills during playback by taking a frame grab from a movie and storing it as a separate file.
Additional Video Features
Support for HDR Content:
- Affording extensive customizable color and gamma controls, the a7R IIIA allows users to adjust the gamma, black level, knee, color level, and more. Also, users can use the same S-Log2 Gamma Curve that is found on high end Sony Cinema cameras that squeezes up to 1300% more dynamic range into the video signal then traditional REC709, for increased post-production flexibility. HLG (Hybrid Log-Gamma) support is also available, along with the BT.2020 color space, for recording within a wide color gamut and, in addition to S-Log2, S-Log3 is also available for producing an effective 14-stop dynamic range with increased grading control in the shadow to mid-tone regions of the image.
Slow & Quick Motion:
- Take more control over your video capture capabilities with a variety of new frame rates available in an S&Q mode. This will allow shooters to capture Full HD video at one of either steps between 1-120 fps. These settings will allow you to slow down action as well as speed up a slow-moving scene. This setting is also NTSC/PAL switchable.
Enhanced Zebra Function:
- An enhanced Zebra function is ideally suited to aid in monitoring exposure values in high-contrast scenes. Video signal level targets can be set from 0 to 109, and specific ranges can be set to make exposure level adjustments easier.
Time Code and User Bit Settings:
- A time code can be used to record hours, minutes, seconds, frames on image data for more precise editing while the User Bit function can record date, time, and scene number to aid in editing together footage from multiple cameras.
- UHD 4K movies and lower-resolution proxy movies can be simultaneously recorded. The smaller proxy files are ideal for quick previewing or pre-editing that can reduce the time required for final 4K editing.
Body Design and Built-In Wi-Fi/Bluetooth
- An updated Quad-VGA OLED Tru-Finder EVF is featured and has a 3.69m-dot resolution for bright, clear viewing in high detail. Both Standard and High-quality settings can be used, depending on the shooting situation, in order to optimize the viewing experience. This updated viewfinder design also affords the use of autofocus in the Focus Magnifier mode as well as improved focusing peaking to benefit manual focus operation.
- In addition to the EVF, a 3.0" 2.36m-dot rear LCD is also available, which has a touch panel design for intuitive operation and focusing control. The screen also tilts upward 107° and downward 41° to benefit working from high and low angles.
- Magnesium alloy chassis assures rigidity, durability, and stability while remaining lightweight. The lens mount has also been improved to better support heavy lenses and the grip rigidity has been improved for more comfortable handholding.
- A durable shutter unit incorporates a coreless motor and brake system that reduces vibrations to better control shutter shock as well as extend its rated lifespan to approximately 500,000 actuations.
- Weather-sealing has been employed to resist dust and moisture for reliable operation in harsh weather conditions.
- Using the same NP-FZ100 battery as the a9, the a7R IIIA has improved battery life and is now rated for approximately 530 shots per charge with the EVF or 640 shots with the rear LCD.
- Dual SD memory card slots allow for flexible file saving and handling and can be configured to partition raw and JPEG files or can be used for overflow recording. One of the card slots is rated to support UHS-II memory cards.
- Integrated PC sync terminal for wired flash sync with strobe packs or wireless radio remotes.
- A USB 3.2 Gen 1 Type-C port has been added, in addition to a micro-USB port, for faster, more reliable tethering support. The USB Type-C connection allows the camera to be charged from the host power source while connected.
- The a7R IIIA features a 3.5mm microphone input jack for compatibility with external microphones. And for users needing more, the camera is also compatible with the Sony XLR-K2M XLR Adapter for recording professional balanced XLR audio signals with phantom power and adjustable mic/line inputs. For monitoring audio, a 3.5mm headphone jack is available as well as real time audio levels for a visual reference.
- Built-in Wi-Fi enables the a7R IIIA to instantly share imagery to mobile devices for direct sharing online to social networking, via email, and to cloud storage sites. NFC (Near Field Communication) is also supported, which allows for one-touch connection between the camera and compatible mobile devices; no complex set-up is required. Once connected, the linked mobile device can also display a live view image on its screen and remotely control the camera's shutter.
- Bluetooth connectivity allows for location data acquisition.
Pixel Shift Multi Shooting
This unique compositing mode allows you to achieve even greater resolution than the 42.4MP sensor affords. Working in conjunction with the sensor-shift image stabilization, this mode shifts the sensor while making four consecutive exposures in order to acquire approximately 169.6MP of information for greater color accuracy and detail than possible with a single exposure. These files can then be merged together during post-production by using the Sony Imaging software suite.
Other Camera Features
- A Ratings function lets you assign star values, from 1-5, to images in-camera for faster editing and sorting at home during post-production.
- An advanced 1200-zone evaluative exposure metering sensor delivers consistent and accurate results using multi-segment, center-weighted, or spot metering modes.
- Highlight and Average metering modes helps avoid blown-out highlights and provide stable auto-exposure, respectively.
- Anti-flicker shooting automatically recognizes and times the shutter action to minimize the flicker effect for more consistent results on still images.
- Picture Effect modes: Posterization (Color), Posterization (B/W), Pop Color, Retro Photo, Partial Color (R/G/B/Y), High Contrast Monochrome, Toy Camera (Normal/Cool/Warm/Green/Magenta), and Soft High-Key.
- Creative Style modes: Standard, Vivid, Neutral, Clear, Deep, Light, Portrait, Landscape, Sunset, Night Scene, Autumn leaves, Black & White, Sepia, Style Box (1-6), (Contrast (-3 to +3 steps), Saturation (-3 to +3 steps), Sharpness (-3 to +3 steps).
||35.9 x 24 mm (Full-Frame) CMOS
||Actual: 43.6 Megapixel
Effective: 42.4 Megapixel (7952 x 5304)
|Image File Format
||Auto, 100 to 32000 (Extended: 50 to 102400)
||1/8000 to 30 Seconds
1/8000 to 1/4 Second in Movie Mode
||Center-Weighted Average, Highlight Weighted, Multi-Zone, Spot
||Aperture Priority, Auto, Manual, Program, Shutter Priority
||-5 to +5 EV (1/3, 1/2 EV Steps)
||-3 to 20 EV
||Auto, Cloudy, Color Temperature, Custom, Daylight, Flash, Fluorescent (Cool White), Fluorescent (Daylight), Fluorescent (Warm White), Incandescent, Shade, Underwater
||Up to 10 fps at 42.4 MP for up to 76 Frames (Raw) / 76 Frames (JPEG)
Up to 8 fps at 42.4 MP for up to 76 Frames (Raw) / 76 Frames (JPEG)
Up to 6 fps at 42.4 MP for up to 76 Frames (Raw) / 76 Frames (JPEG)
Up to 3 fps at 42.4 MP for up to 76 Frames (Raw) / 76 Frames (JPEG)
UHD 4K (3840 x 2160) at 23.976p/25p/29.97p [60 to 100 Mb/s]
Full HD (1920 x 1080) at 23.976p/25p/29.97p/50p/59.94p/100p/119.88p [100 Mb/s]
HD (1280 x 720) at 100p/119.88p [50 Mb/s]
Full HD (1920 x 1080) at 50p/59.94p [28 Mb/s]
Full HD (1920 x 1080) at 23.976p/25p/50i/59.94i [17 to 24 Mb/s]
Full HD (1920 x 1080) at 50p/59.94p [28 Mb/s]
Full HD (1920 x 1080) at 25p/29.97p [16 Mb/s]
HD (1280 x 720) at 25p/29.97p [6 Mb/s]
|External Recording Modes
UHD 4K (3840 x 2160) at 24.00p/25p/29.97p
Full HD (1920 x 1080) at 24.00p/50i/50p/59.94i/59.94p
||Up to 29 Minutes
||Built-In Microphone (Stereo)
External Microphone Input
|Audio File Format
||AC3, Dolby Digital 2ch, Linear PCM (Stereo)
||Auto and Manual Focus
||Automatic (A), Continuous-Servo AF (C), Direct Manual Focus (DMF), Manual Focus (M), Single-Servo AF (S)
||Phase Detection: 399
Contrast Detection: 425
||-2 to +20 EV
|Viewfinder Eye Point
||-4 to +3
||Tilting Touchscreen LCD
||Auto, Fill Flash, Hi-Speed Sync, Off, Rear Sync, Red-Eye Reduction, Slow Sync, Wireless
|Maximum Sync Speed
||-3 to +3 EV (1/3, 1/2 EV Steps)
|Dedicated Flash System
|External Flash Connection
||Hot Shoe, PC Terminal
|Media/Memory Card Slot
||Slot 1: SD/SDHC/SDXC (UHS-II)
Slot 2: SD/SDHC/SDXC/Memory Stick Duo Hybrid (UHS-I)
||3.5mm Headphone, 3.5mm Microphone, HDMI D (Micro), USB Type-C (USB 3.0), USB Micro-B (USB 2.0)
||32 to 104°F / 0 to 40°C
||1 x NP-FZ100 Rechargeable Lithium-Ion, 7.2 VDC, 2280 mAh (Approx. 530 Shots)
|Dimensions (W x H x D)
||5 x 3.76 x 2.9" / 126.9 x 95.6 x 73.7 mm
||1.45 lb / 657 g
|Box Dimensions (LxWxH)
||9.7 x 6.1 x 5.7"
Sony Alpha a7R IIIA Mirrorless Digital Camera (Body Only)
Sony NP-FZ100 Rechargeable Lithium-Ion Battery (2280mAh)
Sony BC-QZ1 Battery Charger
Sony ALC-B1EM Body Cap for E-Mount Cameras
Accessory Shoe Cap
USB Type-C Cable
Limited 1-Year Warranty