Reasons to Choose Sony A7 IV over A7S III
The Sony Alpha A7 IV is Sony's latest full-frame mirrorless camera and successor to the very popular A7 III model. A7 IV is not as video oriented as the Sony Alpha A7S III or not as highly-specced as the flagship Sony A1 but one would argue that it represents the optimal combination of stills and Video at a very reasonable price level ( relative to the other two models at least).
In order to help the user who couldn't make their mind yet about the A7 IV, here we have listed 16 reasons why we would choose Sony A7 IV over A7S III. We know that there are also many areas that A7S bests the A7 IV but for this post, we will be focusing on the pros of A7 IV. Very soon we will also have a follow up post which that time will list the reasons to pick A7S III over the A7 IV.
16 Reasons to Choose Sony A7 IV over Sony A7S III
1- Price
Sony A7 IV body sells for $2499 and Sony A7S III sells for $3499. The $1000 price difference is quite substantial, well not enough to buy you a new GM lens but may a G like the excellent Sony 20mm F1.8G for $899, why not? (It is also much harder to find the A7S III in stock these days in USA.)
2- Higher Resolution Stills
A7 IV has a 33MP sensor whereas the A7S III has a 12 MP sensor. We understand that Sony wants to give priority to High ISO performance and Dynamic Range on the A7S III but the tests show that the 33MP sensor is head to head in High ISO and dynamic range with the 12MP sensor. Besides, 12 MP is so low these days, gives very little room for cropping. Even the APS-C crop (1.5x) mode of A7 IV gives you 14.6MP images.
3 -More Detailed 4K Videos
The higher resolution sensor of A7 IV also helps the video quality, especially at 4K. The A7 IV over-samples a 7K region of its sensor which gives us a 4K video that is sharper and more detailed than A7S III's 4K which is oversampled from 4.2K region of its sensor.
4- Breathing Compensation
Sony A7 IV is the first camera to feature Breathing Compensation option which adjusts the size of the frame dynamically in-camera during video recording by applying a certain percentage of crop in order to minimize the phenomenon called Lens Breathing, where the angle of view changes according to the focusing distance. The limitation is that it only works with a selected list of lenses at the moment, check this list of lenses here. Sony recently added this function to one of its cinema cameras, the FX-6 with a firmware update so there is a chance that it can also be added to the A7S III.
5- Photo, Video and Slow&Quick Dial
The buttons, dials and switches on both cameras are very similar except one significant difference in favor of the A7 IV: A7 IV has an extra dial which is used to quickly switch between Stills, Video and S&Q modes. With this switch, the menu selections also change accordingly. And the implementation is much better than the one found on the Canon R5 C.
Sony A7 IV Stills Video S&Q Dial
6- Better Customisation
In addition to the new mode dial on the A7 IV, it is also possible to configure the settings such as aperture, shutter speed, AF Mode, Metering, ISO, white balance etc. independently between Photo and video mode so the transition between modes is seamless and much faster. It is also possible to configure the various dials separately in Manual mode vs other shooting modes, which makes the A7 IV much better for hybrid use.
7- Anti-Dust Shutter Mechanism
As seen on Sony A1 before, the A7 IV features an option ( that doesn's exist on A7S III ) where you can choose to have the shutter remain closed while changing the lens and the camera is off. This helps to protect the sensor from dust.
8- Lossless Compressed RAW Option
The A7S III only offers two RAW shooting options, the Compressed and Uncompressed whereas the A7 IV has an additional Lossless Compressed RAW option in addition to two other that are the same with A7S III. This file retains all the information while providing smaller file sizes. One disadvantage is that the A7 IV continuous shooting slows down when this option is selected.
9- Animal & Bird Eye AF Tracking in Video
The Real-time Eye AF on the A7 IV can nowdetect and track birds and animal eye for both still images and movies in addition to humans which is an improvement over the A7S III AF which can track human and animal eye in stills and human only in videos.
10 New Dial that replaces the exposure compensation dial
The re-designed dial on the A7 IV has no markings on it and it is not limited to exposure compensation use. Now the new dial rotates without a stop and can be customised to use for other settings.
Sony A7 IV New Customizable Dial replaces Exposure Compensation Dial
11- AF assist function
The A7 IV has an 'AF assist' function which allows the user to change focus manually even when the camera is set to C-AF or Tracking. The A7S II doesn't have this option.
12- Variable shutter
The feature which was first implemented on Sony A1 is now available on the A7 IV as well. This useful feature allows you to set the shutter speed with a higher degree of precision compared to the usual 1/3 step which in return helps to eliminate the flickering of certain light sources inconditions where the standar Anti-flicker wouldn't not be very effective.
13- USB streaming for Webcam
Both the A7 IV and the A7S III can be used as a webcam but the implementaion on the A7 IV takes this a step further by eliminating the need of using an additional software, it is pretty much plug-and-play. It can also stream at 4K (only 15fps though) and Full HD up to 60fps.
14- Focus Map
This is another interesting function that only the A7 IV sports in the SOny Alpha line of cameras. Focus Map when selected shows you the amount of depth of field in your image by overlaying different colors for the zones that are in the foreground, and in the background. The areas that are in focus doesn't have any overlaying colors. I personally don't use this function but can think that some would like it.
15- Higher speed USB at 10Gbps
This may not be important for many users but the USB Type C port on the A7 IV vsn go upto 10Gbps transfer speeds whereas the A7S III can only go upto 5Gbps.
16- Shot Mark Feature
The A7 IV has new feature called 'Shot Mark' which enables the user to mark scenes in desired parts of the video clips, which later can easily be accessed within camera or on Sony’s Catalyst Browse & Prepare applications.
Here we are at the end of our list. To be honest, I was planning to name this post as "10 Reasons..." but as I got in to more detailed, it ended up at 16 reasons. Let is know what you think please. Are there any other reasons that you cna think of in A7 IV's advantage? Are these enough reasons for you to choose it over the A7S II? Please write you opinion in the comments section below.
Check Price and Availability of Sony A7 IV at: B&H Photo / AmazonUS / AmazonCA / AmazonDE / AmazonES / AmazonFR / AmazonIT / AmazonUK / AmazonIN / AmazonAU
Check Price and Availability of Sony A7S III at: B&H Photo / AmazonUS / AmazonCA / AmazonDE / AmazonES / AmazonFR / AmazonIT / AmazonUK / AmazonIN / AmazonAU
| FEATURE and SPECS COMPARISON | |  |  |
| Model | Sony Alpha A7 IV | Sony Alpha A7S III |
| Sensor Resolution | 33.0 MP | 12.0 MP |
| Announced Date | 2021-10-21 | 2020-07-21 |
| Camera Type | Pro Mirrorless | Pro Mirrorless |
| Sensor Type | BSI-CMOS | BSI-CMOS |
| Sensor Size | Full frame | Full frame |
| Sensor Sensitivity | ISO 100 - 51200( expands to 50 - 204800) | ISO 80 - 102400( expands to 50 - 409600) |
| Lens Mount | Sony E | Sony E |
| Image Stabil. | Sensor-shift ( up to 5.5 stops) | Sensor-shift ( up to 5.5 stops) |
| Eye Tracking Focus | | |
| Weight | 659g | 699g |
| Dimensions | 129 x 97 x 81mm | 129 x 97 x 81mm |
| Weather Sealing | | |
| Focus Points | 759 | 759 |
| Min AF Detecting Range | -4eV | -6eV |
| Animal Eye Tracking | | |
| Minimum Shutter | 30 sec | 30 sec |
| Maximum Shutter | 1/8000sec | 1/8000sec |
| Continuous Drive | 10.0fps | 10.0fps |
| Max Video Reso | 3840 x 2160 | 3840 x 2160 |
| Video fps at Max | 60p, 50p,48p, 30p, 25p, 24p | 120p, 60p, 50p,30p,25p,24p |
| Video Formats | MPEG-4, XAVC S, XAVC HS, XAVC S-I, H.264, H.265 | MPEG-4, XAVC S, XAVC HS, XAVC S-1, H.264, H.265 |
| High Speed Video | 120fps | 240fps |
| Max Video Mbps | 600 | 500 |
| Max Video Color Depth | 10bit | 10bit |
| Storage Slot | 2 | 2 |
| UHS Support | UHS-II | UHS-II |
| CFexpress Support | Type A | Type A |
| Battery Life | 600 | 600 |
| Battery Model | NP-FZ100 | NP-FZ100 |
| RAW Video | | |
| Webcam | | |
| Anti Flicker | | |
| Microphone Port | | |
| Headphone Port | | |
| Wifi | | |
| Weather Sealing | | |
| Timelapse | | |
| Screen Type | Fully articulated | Fully articulated |
| LCD Size | 3.00" | 3.00" |
| Screen dots | 1440000 | 1228800 |
| Touch Screen | | |
| Viewfinder | | |
| Viewfinder Type | Electronic | Electronic |
| Viewfinder Coverage | 100% | 100% |
| Viewfinder Magnification | 0.78x | 0.9x |
| Viewfinder Resolution | 3,690,000 | 9,440,000 |
| NFC | | |
| Selfie Friendly Screen | | |
| AF Joystick | | |
| Bluetooth | | |
| Full-size HDMI Port | | |
| Gyro data Stabilization | | |
| Price | Amazon, B&H Photo | Amazon, B&H Photo |