Image Stabilization

The second generation models of Sony's a7 series cameras all benefit from the addition of in-body image stabilization. It's a 5-axis system, meaning the camera can make some correction for pitch, roll, yaw and both vertical and lateral translations (it's easier to make sense of if you see Sony's own diagram, included below).

If you fit one of Sony's OSS stabilized lenses, the camera passes responsibility for pitch and yaw off to the lens since it is likely to be able to correct for a much greater extent of movement than can be achieved by moving the sensor.

Sony says the IS system isn't exactly the same as the one used in the a7 II but would not be drawn on the differences, saying that it should offer comparable performance optimized for the a7R II's higher resolution. Make of that what you can.

To test the performance, we shoot the camera at a range of shutter speeds: first with IS off then with it switched on. We repeat this test at three key focal lengths: 24mm, 55mm and 200mm to check for consistency of performance. We then visually assess the images and break them down into four categories: perfectly sharp, acceptably sharp, visibly blurred and unusuable.

Lenses used:

  • 24mm: Sony FE 24-70mm F2.8 OSS
  • 55mm: Sony FE 55mm F1.8
  • 200mm: Sony FE 70-200mm F4 OSS
24mm
55mm Equivalent
200mm
Stablization On Stablization On Stablization On
Stablization Off Stablization Off Stablization Off

Comparing the On and Off states, it seems the camera's IS is providing around 2.3 - 2.7EV of stabilization, which is broadly consistent with the performance we saw with the a7 II. It's interesting to note that the IS Off figures are worse for the 55mm lens than for the 24mm and 200mm settings. We believe that this is because the lens is so much lighter than the other two (and hence has less inertia to resist movement).

If you like to think in terms of the traditional 1/Focal Length rule-of-thumb, then it's worth noting that we're only seeing around 50% 'Excellent' shots at 1/FL when IS is off. This is presumably because the a7R II's high resolution means any slight camera shake is visible if you look closely. Turn IS on and you can be confident of getting the vast majority of your shots very sharp at least 1.3EV below 1/FL.

A note on using third-party lenses

If you're using a non-native lens on the a7R II via an adaptor, we'd recommend turing its image stabilization off. The adapter we used would report the presence of stabilization to the camera, presumably prompting the camera to hand-off responsibility for pitch and yaw stabilization to the lens, which made for poor results.