Sony a7S III vs a7R III | Differences and Similarities

Photography enthusiasts waited for the a7S III release for a long time. a7S Mark III is the successor of a7S Mark II released in 2015. In this post, we will be comparing the new Sony a7S III against the a7R III full-frame mirrorless camera. The a7S lineup is praised for its performance in low light conditions and video recording ability whereas the a7R series excels at still photography. Note that the successor to the a7R III (Sony a7R IV) is readily available in the market. Let’s jump into the Sony a7S III vs a7R III comparison right away.

Camera ModelCurrent Price & Availability (Amazon)
Sony a7S IIICheck Pricing & Availability
Sony a7R IIICheck Current Price
Sony a7S III vs a7R III | Pricing & Availability

Overview & Features | Sony a7S III vs a7R III

Image Sensor & Processor

Sony a7R III is 2 years older than a7S III. As speculated, the a7S III is also powered by the same BSI-CMOS Exmor R used in a7R III. The readout speed between the two models remains unchanged. a7R III features 42.4 MP effective resolution in contrast with the 12.1 MP in a7S III. Although Sony a7S III does not offer enough resolution, it does boast a larger pixel size which helps the camera to achieve an outstanding low light shooting capability. The larger pixels in a7S III also assists in easy tracking of subjects.

Sony a7R III comes with a Bionz X image processor. However, the newer a7S III comes equipped with a modern Bionz XR processor. The combined power of newer Bionz XR in addition to the Exmor R BSI CMOS image sensor allows the a7S III to record 10-bit videos in 4:2:2 color sampling internally and RAW videos externally.

The a7S III does well in the low light conditions and video recording, thanks to its larger pixels. This full-frame mirrorless camera satisfies the need for videographers. But when it comes to still photography, the a7R camera series in the Sony Alpha lineup is a better choice.

Video Recording

The a7S lineup is tailor-made for video recording. The larger pixels and better processing speed allow a7S III to capture breathtaking 4K videos at 24, 25, 30, 50, 60, 100, & 120 fps with 4:2:2 color sampling. In addition, a7S III boasts being the first one to record 10-bit videos within the Alpha lineup. Unfortunately, the a7R III cannot outperform the new model in 4K or even FHD video recording. With the help of an external recorder, Sony a7S III can do wonders with 16-bit RAW video recording support up to 4K resolution. Keep in mind that 4K RAW video output is only limited to 4K 60p as of now due to the limitations of the compatible external recorders in the market right now. This may change in the future. On the other hand, Sony a7R III cannot shoot RAW. It can only shoot 4K 8-bit videos up to 30 fps supporting 4:2:0 color sampling internally and 4:2:2 externally.

Going into FHD recording, a7S III records 1920 x 1080 videos at 24, 25, 30, 50, 60, 100, & 120 fps with 4:2:2 color sampling. Sony a7R III also shoots full HD videos up to 120 fps. However, due to 4:2:0 internal color sampling and 8-bit video recording limitation, it does not provide much room for color correction in post-production.

HDR is a new addition in the a7S lineup with the Sony a7S III model. But the a7R III already supports HLG HDR, up to 15 stops. Both models support MPEG-4, AVCHD, & XAVC S video formats. The a7S III also supports the highly advanced H.265 codec as well. Therefore, a7S III can store videos with a lower size without compromising quality.

Monitor & Viewfinder

Sony a7S III is superior to a7R III as it provides a fully touch articulate TFT LCD monitor. Both models feature a 1,440,000 dotted 3″ TFT LCD monitor. Even though the specifications of the monitors are comparable, the articulating display in Sony a7S III allows the user to have a better degree of freedom while recording or shooting photos. Many vloggers are extremely happy about this update.

Moving on to the viewfinder section. The newer a7S III comes with a 0.64″ 9,437,184 dot Electronic viewfinder. It is the first 9.4M dotted viewfinder. Whereas, Sony a7R III features a 0.5″ 3,686,400 dot Electronic viewfinder. It is safe to say that Sony a7S III is undoubtedly superior to a7R III in terms of viewfinder and monitor quality.

Image Stabilisation & Autofocus

Both a7R III & a7S III features the same 5-axis sensor-shift image stabilization technology, up to 5.5 stops. However, Sony compared the stabilization of a7S III to gimbal-like footage during the product launch.

Now coming to the autofocus section, both models feature phase-detection and contrast-detection AF. They support 425 contrast detection focus points. When it comes to phase-detection, Sony a7S III supports whopping 759 phase-detection AF points which is far more than 399 focus points in a7R III.

Sony a7S III is the first in Alpha lineup to provide a full touch screen. A photographer can rely on the camera to track the object or manually touch the screen to focus on subjects.

ISO & Shutter speed

Sony a7S lineup features better sensitivity than the other Alpha lineup. Also, the S in the model name stands for sensitivity. Now that there is a new sensor in a7S III, we can raise the ISO to a whole new level without increasing noise. The extended ISO range of a7S III goes from 40 – 409600. Sony a7R III on the other hand offers a standard ISO range from 100 to 32000 (Extended: 50 to 102400).

Both models support a shutter speed from 1/8000 s to 30 s. Also, both models provide up to 10 fps continuous drive speed.

Other Features| Sony a7S III vs a7R III

Sony a7S III and a7R III feature 2 storage slots (SD/SDHC/SDXC). However, a7S III also supports the newer CFexpress Type A card. Type A is smaller in size than its predecessors and has a higher writing speed. This in turn allows a7S III to write out at better speeds. Both a7R III and a7S III features 3.2 Gen 1 USB. The battery life of a7R III is 650 CIPA, superior to the 600 of a7S III.

Specifications | Sony a7S III vs a7R III

Sony a7S IIISony a7R III
SensorBSI-CMOS Exmor R Full FrameBSI-CMOS Exmor R Full Frame
ProcessorBionz XRBionz X
Effective Resolution12.1 MP42.4 MP
File Format for Still ImagesJPEG, 14 – bit Raw, & HEIFJPEG, & 14 – bit Raw
Image Stabilization5-axis BIIS5-axis BIIS
AutofocusPhase Detection AF/Contrast Detection AFPhase Detection AF/Contrast Detection AF
AF Focus Points759 : Phase Detect
425 : Contrast Detect
399 : Phase Detect
425 : Contrast Detect
ISO Range (Extended)40 – 40960050 to 102400
Shutter Speed1/8000 s – 30 s1/8000 s – 30 s
Continuous Drive Speed10 fps10 fps
4K Video Recording@120 fps – 10 bit 4:2:2 internally, & externally@30 fps – 8 bit 4:2:0 internally
@30 fps – 8 bit 4:2:2 externally
RAW Video16 – bit externallyN/A
4K Video Recording Frame Speed24, 25, 30, 50, 60, 100, & 120 fps24, & 30 fps
FHD Video Recording Frame Speed24, 25, 30, 50, 60, 100, & 120 fps24, 25, 30, 50, 60, 100, & 120 fps
Viewfinder0.64″ 9,437,184 dot Electronic0.5″ 3,686,400 dot Electronic
Monitor Type3″ TFT LCD articulating display3″ TFT LCD tilting display
Monitor Resolution1,440,0001,440,000
Storage2 Slots (SD/SDHC/SDXC/CFexpress Type A)2 Slots (SD/SDHC/SDXC)
USB Type3.23.2
Battery Life (CIPA)600650
Current PriceCheck PriceCheck Price
Sony a7S III vs a7R III | Specifications

Sony a7S III did not disappoint videographers and is definitely a big deal in the mirrorless world. But we now have other competitors in the market as well such as Canon R5 which can shoot videos up to 8K. If you’re a photographer who deals with large prints and cannot compromise with image resolution, a7R III would definitely be a better choice for you in that case. Don’t forget that there is a successor to Sony a7R III in the market as well – Sony a7R IV.

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Adarsh R

A blend of a photographer, a movie lover, and now a writer.