A Comparison of the Autofocus in the a7R III, a7R IV, and a9

Sony's a7R III, a7R IV, and a9 are some of the latest and greatest from the camera manufacturer, and with them come some powerful autofocus capabilities for demanding photographers. How do the three cameras stack up against each other? This excellent comparison review takes a look at the autofocus systems in all three cameras to help see which is right for you. 

Coming to you from Dustin Abbott, this excellent video takes a look at the autofocus systems of the a7R III, a7R IV, and a9. All three cameras have some mightily impressive autofocus capabilities, but there are differences in each, and if you are shooting anything that relies heavily on AF capabilities (sports, wildlife, etc.), what are seemingly minutiae in capabilities can end up making the difference in whether you get the shot you need or not. Unsurprisingly, the a9 still seems to hold the top honors, but the R series cameras offer near-flagship levels of AF performance, and that combined with their resolution and respectively fast continuous rates may tip photographers' preferences in their direction. Check out the video above to hear Abbott's full thoughts on all the systems. 

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Alex Cooke is a Cleveland-based portrait, events, and landscape photographer. He holds an M.S. in Applied Mathematics and a doctorate in Music Composition. He is also an avid equestrian.

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I always enjoy his videos. It would be nice if someone could quantify the difference maybe by setting up a running toward the camera burst and count the percent in focus for all the cameras.

I've done something very similar when comparing the 100-400 vs 200-600. I used the a6400, a7III, a7R III and a9 and had my dog Frank running towards me. I counted the shots in focus afterwards. I'll be doing something similar with the a7R IV soon. I don't want to drop a link here but if you search YouTube for "Sony 200-600 vs 100-400 AF Keeper Test with 4 Cameras Tested" it should come up. The a7R III is the slowest but still nails a good number of shots, then comes the a6400 and a7III which are very similar in good light, then the a9 which is comfortably on top. Of course different subjects, speeds and light will all vary the results.

I disagree, his videos are dry, drone on with long takes and even multiple “parts”, so much verbal filler to hit YouTube 10/20 minute plateaus, non-edited and questionably edited (sepia?!) photos, etc. Also, this video in particular has a giant phallic shadow on him the entire time from that canon 100-400 in his Sony video. Poor lighting choice there.