The Sony a7 IV is the company’s latest mid-range full-frame mirrorless camera, whereas the a7R III is a four year-old high-end, high-res model, so at first glance, they’re not the most obvious cameras to compare.
However, Sony’s habit of keeping older models in its lineup means they’re both still available. And, because the a7 IV is new, and still commanding its full MSRP, whereas the a7R III has been marked-down to sit below the fourth ‘R’ model, it seems like they’ll be comparable in price, at least at the moment.
A refresh, in the form of the a7R IIIA (ILCE-7RM3A), gains a higher-resolution rear display, suggesting Sony plans to keep it around for a while longer, so we think it still makes sense for us to try to address which of the two cameras is better.
Given that most modern cameras are very good, this article won’t simply declare one camera to be better than the other. Instead we’ll try to point out the relative strengths and weaknesses, so that you can work out which will be better for you and your photography.