Sony’s A7 series has long been their most popular camera series, hitting the sweet spot between specs and price, and the brand new Sony Alpha A7 IV was unveiled on October 21st.
The previous Alpha A7 III was one of the best-selling full-frame mirrorless cameras of all time, but nearly four years later, it may have outlived its usefulness.
Because Sony has already revealed all of the key specifications for the new A7IV version, we can now compare the two models to see what’s changed.
Why would you buy the new kid on the block when the street price of the 4-year-old A7 III is significantly lower than the A7 IV at launch? We’ve put together this detailed Sony A7 IV vs A7 III comparison to help you decide between the two.
The A7 III features a 24.2-megapixel BackSide Illuminated (BSI) Exmor R sensor that produces excellent still images and 4K video.
The sweet spot for most recent entry-level and mid-range mirrorless cameras is 24 megapixels, with much higher megapixel counts reserved for premium flagship models.
Backside Illuminated (BSI) is a special manufacturing process that should result in better image quality in low-light situations than cameras with the same number of megapixels that do not use a BSI sensor.
The A7IV ups the ante by employing a newly developed 33 megapixel Exmor R BSI CMOS sensor, which will presumably become the sensor of choice for all of Sony’s future entry-level and mid-range full-frame cameras.
This new sensor gives it a resolution advantage over the previous A7III (by 27 percent) as well as rivals such as the Canon R6, Nikon Z6 II, and Panasonic S1, while not stepping on the toes of the 42 megapixel A7R III or the 61 megapixel A7R IV.
The new A7 IV camera employs the most recent BIONZ XR processor, which was previously found in the A7S III camera and offers a whopping 15+ stops of dynamic range.
This processor also has 8x the processing power of the BIONZ X processor found in the A7 III, which is no slouch either.
There’s almost nothing to choose between the two models here, with both the A7 III and A7 IV offering ISO ranges up to 204,800.
Both cameras have a native ISO range of 100-51,200 for stills, which can be increased two stops to ISO 204,800 and can be reduced to ISO 50 if necessary.
For video, the A7III has an expanded ISO range of 50-204,800, whereas the new A7IV starts at ISO 100 and goes up to 102400.
The A7IV records 4K UHD video in the XAVC S-I format at up to 60 frames per second at 4:2:2 color depth is 10-bit to the inserted memory card or over HDMI to compatible third-party recorders using either Long GOP or All-Intra frame encoding.
In full-frame, 4K/30p video is oversampled from 7K, but in APS-C Super 35 mode, 4K/60p video is oversampled from 4.8K.
When shooting in 4K at 30p, the camera uses the entire width of the image sensor to oversample from 7K of data, but when shooting at 60p, a 1.5x crop is applied.
It is compatible with the S-Cinetone, HLG, S-Log3, and S-Log2 profiles.
The older A7 III has no 4K/60p or 10-bit recording, and it also crops 4K/30p video by 1.2x, so while Super 35mm 4K/60p on the A7IV is disappointing, it’s still a significant improvement over the Mark III camera.
They can both record Full 1080 HD at up to 120fps, with dedicated Slow and Quick motion modes ranging from 1fps to 120fps.
The A7 IV also inherits a number of features from the A7S III that distinguish it from the A7 III.
These include AF Speed settings for the A7S III, no recording time limits, a blue peaking color, the ability to shoot vertical videos, live streaming support, and dual NTSC and PAL recording on the same memory card without having to reformat it.
Furthermore, the one-touch movie button has been relocated from the rear of the A7 III to the top panel of the A7 IV, from where it was rather awkward.
The Sony A7 IV also supports the Digital Audio Interface (via MiShoe), which allows you to use the ECM-B1M digital shotgun microphone.
The new A7IV also includes new video settings not found on the A7III, such as Breathing Compensation to help reduce focus breathing with certain Sony lenses, Shockless White Balance to make manual white balance changes more smooth, Flexible Exposure Mode to switch between auto and manual exposure settings separately for the aperture and shutter speed, and two types of Shot Marks to mark favorite takes or scenes.
The A7IV inherits the A7S III and A1 models’ ten Creative Look presets for JPEG images, and an additional six ‘custom’ presets can be manually stored for quick access.
These can be applied to both stills and video, as well as USB streaming, whereas the Creative Styles on the A7 III were really only intended for still photos.
Standard (‘ST’), Portrait (‘PT’), Neutral (‘NT’), Vivid (‘VV’), ‘VV2’, ‘FL’, ‘IN’, ‘SH’, Black & White (‘BW’), and Sepia (‘SE’ are the presets.
The auto-focus system on the A7 IV supports Real-time Tracking AF as well as Human, Animal, and Bird Eye AF for both stills and movies, making it the first Sony camera to offer such comprehensive AF support for both shooting modes.
The A7 III didn’t come with these features when it was first released, but Sony added real-time Eye AF for animals (but not birds) with the Version 3.0 firmware update at the end of 2020.
It only works for stills, not video, and the A7 III does not support Real-time Tracking AF at all, instead of sticking with the previous Lock-On AF system.
Sony claims that the accuracy of the Eye AF has been improved by 30% when compared to the previous A7 III.
The new A7IV has the same autofocus system as the A7S III and A1, with 759 on-sensor phase-detect points and 425 contrast-detect points that work down to -4EV.
For burst shooting, the autofocus system on the A7 IV works down to f/22 versus f/11 on the A7 III.
It also has the most recent focusing algorithm, which is the same as the one used by the recently released A7S III, which is said to improve the already excellent AF tracking system.
This is slightly better than the A7 III, which has 693 phase-detection points covering 93 percent of the frame, as well as 425 contrast-detection points, with the system working down to -3EV low-light.
The AF Assist function, which is new to the A7 IV for videographers, smoothly switches between auto and manual focus by rotating the focus ring to switch into MF and shift focus to a different subject, with AF resumed when the ring rotation stops.
The Focus Map feature, which allows you to easily visualize the depth of field while shooting, is also new. When enabled, Focus (depth map) information is overlaid in real-time on a display of the live view, making it easy to see which areas are in or out of focus.
When it comes to the top continuous shooting speeds, the two models are perhaps surprisingly evenly matched.
Both offer 10fps burst shooting with Full AF/AE tracking, though the A7IV only does so when shooting JPEGs and/or compressed Raws.
However, if you want to shoot either uncompressed or lossless compressed Raw files, the burst speed drops dramatically to just 5-6fps, which we believe many users would prefer.
It should be noted that the A7III does not support the lossless compressed format; it can only be compressed or uncompressed.
With main competitors like the Canon EOS R6 offering 20fps burst shooting, the A7IV’s decision to stick with the fastest 10fps speed is somewhat perplexing.
The A7 IV, on the other hand, has a much larger buffer than the A7 III, especially when shooting Raw files, with the ability to shoot at 10fps for up to 830 JPG+RAW (uncompressed) or 1,000 JPGs, lossless compressed or compressed RAW in one high-speed burst, whereas the A7III could only manage a still very respectable 79 JPG+RAW images or 82 JPGs, 89 compressed RAW or 40 un
There is one major caveat to the A7IV’s improved buffer: it can only be achieved when using a Cfexpress Type A card, which is significantly more expensive than SD cards, with the fastest rate dropping to 8fps if you use the latter.
The A7 IV does not follow in the footsteps of its older brother; instead, it has a nearly identical body design and uses the same heatsink system as the A7S III.
The Sony A7IV is surprisingly small for such a feature-rich camera. Despite being slightly larger and thicker than its predecessor, it has a magnesium alloy body that weighs only around 658g with battery and memory card installed, just 8g more than the A7 III.
The Alpha 7 IV will feel very comfortable to hold thanks to a generous handgrip.
The body’s sealing has been improved, allowing it to be relied on in adverse conditions. It also has a design for ‘heat dissipation.’
That means no fans, no overheating, and an unlimited number of video recording hours in any resolution.
There’s a shooting mode dial on top, with a new separate Photo / Video / S&Q switch underneath, and the camera remembers basic exposure settings in each mode, a first for a Sony Alpha camera.
Although there is no top LCD panel, there is a one-touch movie record button, twin exposure dials, and a brand new unmarked, lockable dial that can be customized to set either the shutter speed, aperture, ISO speed, drive mode, focus mode, or, as traditionally, exposure compensation.
The new full-size HDMI port, which is superior to the micro HDMI port found on the A7 III, allows you to connect an external monitor directly to the A7 IV.
Finally, the A7IV inherits the most recent menu system from the A7S III and A1, rather than the A7III’s outdated, clunkier menu.
The A7 IV, like the A7S III, has built-in image stabilization worth up to 5.5 shutter speed stops.
It also receives a new feature called Active Mode, which improves stabilization for movie shooting and was inherited directly from the A7SIII.
The older A7 III has a 5-axis in-body image stabilization system as well, but it only provides up to 5 stops of stabilization and does not support Active Mode.
Like the A7S III, you can use data from the camera’s gyro sensor and the Sony Catalyst software to stabilize A7IV footage in post-production.
The A7 IV features a higher-resolution, 3.69m-dot EVF with a refresh rate of up to 120fps, similar to the A7R III and A9 II models.
This model has 100 percent scene coverage, 0.78x magnification, and a high frame rate option of 120fps to help track moving subjects more smoothly and with little lag.
This is superior to the older A7 III’s 2.36 million dot XGA OLED electronic viewfinder, which has the same magnification but is lower-resolution and only goes up to 60fps refresh rate.
The A7 IV features a fully articulating 3-inch, 1.03-million-dot LCD screen with improved touchscreen functionality, including focusing and navigating the significantly improved user interface and main menu system.
The screen on the A7 IV is a vari-angle design inherited directly from the A7S III, which for some users will be a significant improvement over the A7 III’s more limited 180-degree flip-up design.
You can flip the screen out to the side, rotate it forward for easier operation when pointing the camera at yourself, and fold it flat against the back of the camera to protect it from scratches.
Simply put, it’s a much more versatile screen for vlogging, filming, and photography in general.
The Sony A7 III was clearly ahead of its time in that it was one of the first mirrorless cameras to have two SD card slots, though only one of them supports the faster UHS-II standard.
The new A7 IV also has dual card slots, but one of them can now accept UHS-II SD cards as well as faster CFexpress Type A cards, just like the A7S III.
The Sony A7 IV employs the same high-capacity NP-FZ100 battery as the A7 III, A7C, and A6600 models.
It has a CIPA-rated battery life of 610 shots when using the LCD screen, which is actually less than the A7 III’s battery life of 710 shots (for the LCD screen), possibly due to the faster BIONZ XR processor.
Both cameras can also be powered and charged via a USB-C connection, which is useful if you’re on the go and have a compatible power bank nearby.
The new A7IV has the fastest 5GHz Wi-Fi connectivity, whereas the older A7III is limited to 2.4GHz.
The Sony A7 IV is the latest camera to be released in 2021 that offers in-camera USB streaming – 10Gbps live streaming via its USB-C port, to be precise – allowing you to use the camera as a webcam. It can support up to 4K/15p or, more importantly, 1080/60p.
The much older A7 III model does not provide such a seamless experience; instead, it must be converted into a webcam using Sony’s Imaging Edge software.
The price of the new Sony A7 IV is one of the more contentious aspects of the device.
It costs £2399 / €2799 / $2499 body-only in the UK, Europe, and the US, which is significantly more than the current street price of the A7 III, which is around £1699 / $1799.
While the A7 III has been on the market for a few years and has naturally decreased in price, we believe Sony is being overly ambitious with the A7 IV.
It is no longer the “entry-level” model that its predecessor clearly was; instead, the A7 III will continue in that role, along with the more compact Alpha A7C (Sony always sells previous models).
Developing a successor to one of the most popular full-frame cameras in recent years was always going to be difficult, especially in light of rising prices and component shortages.
A lot has changed in the four years since the A7 III was released, and the new Mark IV is clearly a much more capable hybrid camera than its predecessor, at least on paper.
However, it is significantly more expensive than its older brother, as well as main competitors such as the Canon EOS R6, Nikon Z6 II, and Panasonic S1R.