Is the Alpha 7S II the best choice for those specialising in video and low-light photography? Michael Topham finds out how well it performs in these two key areas
Sony Alpha 7S II Review – Image Quality: Detail and Noise
The big appeal for still photographers is the Sony Alpha 7S II’s extensive ISO range. Those curious of how well the 7S II performs at its high sensitivity settings will be astonished by the sensor’s capabilities and by how far the sensitivity can be pushed. As the opening shot to this review shows, it’s possible to achieve acceptable results right up to ISO 25,600. There are signs of luminance noise and colour noise when you push the sensor to its extremes by entering its expanded settings, but provided you’re vigilant and apply noise reduction carefully in post-production, it’s possible to shoot at the ‘mid-range’ of ISO 6,400, 12,800 and 25,600 comfortably. Although the Alpha 7S II’s sensor has nothing on that of the 7R II when it comes to the level of detail it resolves, our resolution results reveal the amount of detail that is resolved remains fairly consistent throughout the ISO range.
Unlike the Alpha 7R II, the 7S II employs an optical low-pass filter. Inspecting raw files under close scrutiny indicates the 12MP chip resolves a maximum of 2,400l/ph at ISO 100. While this is a long way from the level of detail we’re used to seeing high-resolution full-frame sensors resolve, it’s on a par with the original Alpha 7S. It attains the 2,400l/ph figure up to ISO 3,200, dropping only slightly to 2,200l/ph at ISO 6,400. The sensor maintains an impressive level of detail right up to ISO 25,600, ending up at 1,800l/ph at its ISO ceiling.
Converting our raw files using Adobe DNG Converter v9.2 and inspecting them closely at 100% enabled us to establish how well the camera performs through its ISO range. Images are very clean from ISO 100-1,600 and it’s only when you push up to ISO 3,200 that luminance noise creeps in. You’ll be hard pushed to notice this luminance noise at ISO 3,200 and ISO 6,400 unless you inspect the shadows in your images incredibly closely, and I found it possible to create clean results at these settings by increasing the luminance-noise-reduction slider to a value of 30 in Lightroom. Pushing up to ISO 12,800 and ISO 25,600 introduces more luminance noise, yet detail and texture remain high at both these settings. Users could turn to ISO 51,200 if needs must, but fine texture and detail do get lost. ISO 102,400, 204,800 and 409,600 sound impressive but they’re best avoided.