Sony Alpha A7s Mark II review
Written by Gordon Laing
To compare the real-life quality between the Sony Alpha A7s Mark II and Alpha A7r Mark II, I shot this scene with both cameras moments apart using the same lens, the FE 55mm f1.8 set to f8. Both cameras were also set to their base sensitivity of 100 ISO and metered the same exposure. Until the A7s II is supported by Adobe Camera RAW, I’m comparing JPEGs here straight-out-of-camera.
In the crops below, you’re comparing the 12 Megapixels of the A7s Mark II with the 42 Megapixels of the A7r Mark II, and unlike many head-to-heads these days, the differences are obvious to say the least!
As you’d expect, the Alpha A7r Mark II is significantly out-resolving the A7s Mark II in every respect. The difference is absolutely clear in a sample like this, which is packed with detail. You’ll see it in the grills, signs, windows, brickwork – absolutely everywhere. If you’re a detail fanatic the A7r Mark II gives you it in spades and should of course be your preferred choice in the Alpha lineup.
But the A7s II is not about recording the finest details – it’s about delivering lower noise at higher ISOs, so it’s onto my next results page which compares both cameras at each sensitivity. Check out my Sony A7s Mark II noise results or if you’ve seen enough, check out my Sony A7s II sample images!
Sony Alpha A7s Mark II vs Alpha A7r Mark II noise
To compare noise levels under real-life conditions, I shot this scene with the Sony Alpha A7s Mark II and Alpha A7r Mark II at each of their ISO values. I fitted both cameras with the same FE 55mm f1.8 lens set to f8 and disabled DRO. The full view is pictured opposite with the red rectangle indicating the area I cropped; note I’m comparing out-of-camera JPEGs here until the A7s II is supported by Adobe Camera RAW.
The most obvious difference as the sequence of crops starts below is again how much more detail the Alpha A7r Mark II is capturing. You can see it most clearly in the texture of the cushion on the left side – you can resolve the material on the A7r II crops, but it’s virtually non-existent on the A7s II crops, especially as the ISO increases.
The big question though is at what point do the fatter pixels of the A7s II give it a noise advantage over the A7r II. Unfortunately this isn’t easy to see with out-of-camera JPEGs as Sony’s adaptive noise reduction is good at retaining detail in certain regions. For example, the texture on the cushion is only really lost here on the A7r II at around 6400 ISO, but conversely I’d say the background looks better on the A7s II from an earlier point in the range.
I’d also say the A7r II crops are looking muddy from 6400 ISO upwards, steadily losing saturation and detail as the ISO increases. Meanwhile the A7s II may not be a miracle-worker, but it’s definitely cleaner and better-saturated at very high ISOs. Just look at the maximum sensitivity of the A7r II at 102400 ISO: neither camera looks great at 100%, but the A7s II is definitely preferable.
Sony Alpha A7s Mark II vs Alpha A7r Mark II noise (A7r II down-sampled to 12MP)
But this first table is comparing the native output from each camera. What if you reduce the resolution of the A7r II files to 12 Megapixels? For a second comparison I reduced the image size of the A7r II images to match the resolution of the A7s II in Photoshop, using the Bicubic Automatic option and you can find the results in the second table below. This time I’d say the noise levels look similar up to 25600 ISO, and arguably at 51200 ISO too. At 102400 ISO and onwards, the A7s II JPEGs look a little cleaner, but this quick test does prove you can ‘downgrade’ the A7r II resolution to deliver similar looking stills to the A7s II. It may also be possible to achieve a better result by shooting at a lower image resolution in-camera, or by down-sampling with different sharpening later.
Above left: Sony A7s II, above right: Sony A7r II (at 12MP). 100% crops from JPEGs at 102400 ISO
Comparing RAW files will tell the whole story and I’ll update this page with a RAW comparison soon. But in the meantime I’d say there appears to be little benefit to the A7s II over the A7r II if you’re shooting stills. In their native resolutions, the A7r II can easily out-resolve it, and if you’re willing to downsample the A7r II to 12 Megapixels, you’ll achieve a similar result across most of the sensitivity range.
Where the A7s II has the advantage though is when it comes to video, especially 4k video, where its fatter pixels provide better high ISO performance. Next check out my Sony A7s II sample images.