Sony Alpha 7S II Review – Performance
Venturing out on a winter’s evening at dusk was a good test of the Fast Intelligent autofocus system and its ability to acquire focus in scenes with little contrast. Although it doesn’t feature Sony’s impressive Fast Hybrid AF system as found within the Alpha 7R II, the contrast-detection system the Alpha 7S II employs is competent at acquiring focus when the light levels drop very low. I didn’t find the lock-on speed to be quite as responsive as Sony’s Fast Hybrid AF system, but it’s not slow or sluggish. I was half expecting it to struggle in the low-light scene I presented it with, but other than one occasion where a plume of steam engulfed the lens, it established focus on my subjects without any sign of difficulty.
The Alpha 7S II displayed no signs of difficulty focusing on the steam locomotive in this low light scene
Provided there’s sufficient ambient light, the AF system does a good job of acquiring focus when recording video too. Hitting the movie-record button and focusing between near and far subjects revealed the Alpha 7S II is twice
as fast as the Alpha 7S in this department. This is welcome news for videographers and answers the criticisms of its predecessor’s leisurely focusing speed when recording video.
Another feature that makes the Alpha 7S II such an impressive performer in low light is its 5-axis image-stabilisation system. The effect of this is so powerful that it’s clearly visible on the rear LCD or through the viewfinder when shooting stills and recording video. It’s particularly effective with the latter, turning what would otherwise be shaky handheld movie footage into smooth video that looks like it could have been captured with the camera mounted to a tripod.
The 5-axis image stabilisation helped to stabilise this handheld image that was taken at 1/30sec
In low-light scenes I had no trouble capturing sharp images of static subjects with 1/10sec shutter speed at 70mm. Taking the test further, I dialled in shutter speeds of 1/8sec and 1/5sec and continued to record sharp shots at the same focal length provided the EVF was braced against my eye. It was only when I reduced the shutter speed to 1/4sec and 1/3sec that I couldn’t prevent camera shake creeping into my images.
The camera excels with regard to its video performance, too. The new S-Log3 profile is a hand-me-down from Sony’s high-end camcorders and allows users to colour grade video to the same standard while preserving consistency between footage captured on different Sony cameras. In the past, the camera’s Log settings have displayed a rather flat and murky feed, but to get around this Sony has added a gamma display assist function, where a filter is applied to the image displayed on-screen so you can view images with natural contrast while recording. I found this particularly helpful when monitoring images and checking focus.
Those who want to shoot slow-motion video at 120fps in full HD should also note that the sensor crops the image by 2.2x in this mode, but the results are spectacular. In other areas, the metering system produces accurate exposures and I used the zebra-pattern function regularly to ensure highlight detail was never lost. The viewfinder’s colour is a little undersaturated when you compare it to the scene as viewed by your eyes, but it does refresh quickly and it’s great to be able to raise the camera to your eye to inspect images and video in high-contrast conditions.
This high-contrast scene proved to be no problem for the A7S II’s metering system which performs admirably
The Alpha 7S II does use its power quickly, though. With this in mind, you’ll want to build up a collection of spare batteries to swap over at a moment’s notice or look at an alternative solution – the Atomos Power Station being a good example.
