Sony A7S II High ISO & low light test

We finally got the new Sony A7s II in for review thanks to B&H Photo! The Sony Alpha 7S II has a bunch of useful features which you will see soon in our upcoming review. One of the interesting things about this mirrorless 4K camera is the ability to shoot at high ISO values with low image noise compared to other cameras on the market right now.

Even though we don’t often shoot above ISO 3.200 with most cameras it’s very useful to have the option to do so. The A7S II is a full frame DSLM which means the depth of field is very shallow. In case you don’t want that shallow DOF it’s great to be able to use a higher ISO and close the aperture to create a deeper DOF without running into problems regarding the image noise.

We recorded some clips in the evening while it was getting dark. The camera was set to Ultra HD resolution (3840×2160 pixels). The picture profile is S-Log3 S-Gamut3 to keep the image flat. It’s pretty amazing how high the ISO can be pushed without noticing too much noise. All clips were filmed above ISO 3.200. The lowest ISO available in S-Log is 1.600! The highest ISO is 409.600 which is crazy and not really needed but surely welcome. It’s still unbelievable to me because a few years ago shooting “clean” video at ISO 1.600 with cameras like the Canon 7D or Nikon D7000 was a milestone in digital video recording. But before you get too excited: You probably won’t end up shooting at ISO 409.600 a lot because the image noise is very visible and for most scenarios it’s just too bright.

The screen grab below was taken from a 4K video clip with the picture profile S-Log3 S-Gamut3 at ISO 409.600. On the left is the ungraded original frame and on the right is an extreme underexposed version. It’s the same shot just “corrected” heavily. Even the underexposed version shows much more than the human eye could possibly see.

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You might ask yourself now: What’s the highest usable ISO that can be used without seeing too much noise? That’s not so easy to answer because it depends on how much light is in the shot. If you shoot at night in the forest without any artificial light the image is going to look very noisy but if you shoot with in a city with available light the shots can look very good. To make it short and easy: I wouldn’t recommend shooting above ISO 80.000. But don’t forget, the noise will be more visible when shooting with a flat picture profile like S-Log3 due to the high dynamic range / lack of contrast compared to other profiles.

We only graded the footage a bit so the image doesn’t look too contrasty. At the end of the video you can see some side-by-side shots before and after grading.
The more the footage is being pushed in while grading it in post the more noise and grain will be visible.

We are currently using the A7S II with a Metabones adapter so we are able to use Canon lenses. To shoot above ISO 12.800 we didn’t need to film wide opened. We decided to film most of the low light footage at aperture F/4 otherwise everything would be heavily overexposed which we wanted to avoid. We used the trusted Canon 24-105mm F/4 for a lot of shots.

More information and tests coming soon in our video review.

You can buy the Sony Alpha 7S II HERE at B&H!

You can buy the Metabones T Smart Adapter Mark IV HERE at B&H!

Written by Moritz Janisch

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