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Sony A7r/A7/A7s manual focus comparison

horshack

New member
The Sony A7r, A7, and A7s have varying levels of maximum magnification for manual focusing, based on their different megapixel counts. I've made a video demonstrating how the magnification level affects the ease at which a subject can be manually focused. Shot with a Voigtlander 40mm Ultron II lens (Nikon mount) @ f/2.8 at a subject distance of 9 1/2 feet. Live View output was captured over HDMI with a HyperDeck Shuttle 2, using the Apple ProRes 422 codec.

Sony A7 Series Manual Focus Comparison

Switch to 1080 HD for best viewing
 

horshack

New member
So you can focus sharper with the A7r?
Potentially. For distant subjects and/or small details it's certainly easier to MF with the A7r, and the fact that the details are sharper inspires more confidence that critical focus has been achieved. For situations where the details don't look sharp on the A7/A7s, MF can still be achieved by finding the middle of the defocus range.
 

horshack

New member
Here is the same test as before but in low-light conditions (f/4 1/80 ISO 12,800). The results are surprising - the A7s fares much worse in terms of noise vs the A7r/A7. Something is off in how the A7s is generating its magnified view; it appears to be doing some form of interpolation/magnification from a lower-res sample off the sensor.

Sony A7 Series Low-Light Manual Focus Comparison
 
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