Sony A7III VS A7RIII
I own both the Sony A7RIII and the Sony A7III, but I when I’m forced to bring just one camera body however, I always go for the A7III.
This may strike many people as odd, after all, Sony has marketed the A7III as a entry level full frame camera, while the A7RIII is their premiere, professional, photographic workhorse. The cost reflects this as well, The A7III retails for around $2,000 while the A7RIII retails for approx. $3,200.
At first glance, the cameras seem to match on nearly everything except for the megapixels of the camera. Both cameras are capable of 10 frames per second, can shoot 4K video, and slow motion at 120 Frames per second at 1080P.
Why? well, many reasons, but for starters, I shoot a both photos and videos. It’s about a 50/50 split for me.
For most applications I feel that 42 megapixels is too much, I generally don’t crop that much, and large file sizes just eat up hard drive space requiring me to buy drives more frequently. Also, most of my work is going online and will be compressed down to a maximum of 2000 pixels wide anyway. If you are shooting products in studio or landscape images where extreme detail is needed, you would obviously be better off with the A7RIII.
The A7III also slightly outperforms the A7RIII in low light, producing less noise in scenarios requiring high ISO settings.
This is the real kicker. 24 megapixels seems to be the sweet spot when it comes to DSLR’s and compression ratios for video. A 24 megapixel image is derived from a sensor measuring 6000 X 4000 pixels, the equivalent to 6K. The A7III utilizes the entire sensor, downsampling 6K resolution down to 4K. This results in super sharp footage and excellent color replication. The processor in the A7RIII is not capable of this, so it crops in when filming, not utilizing the entire sensor. The result is a 5K downsample to 4K. The visual difference is minor, but it is noticeable at times. It’s more annoying not being able to utilize the entire scope of your lens (because of the crop factor). So if you set up a shot in photo mode instead of video mode, then hit record, it will “bump” in forcing you to recompose your shot.
Additionally, less pixels (which make them larger) do better in low light, which is more visible in video than in stills, so if you’re doing more video than photo, footage from the the A7III will look cleaner.
Here’s a short video I produced on the differences: