April 23, 2017 at 1:23AM

2

Seriously, how do you get rid of the noise in Slog 3 (Sony a7s II)?

How do I stop getting noisy footage from the the Sony A7s Slog-3?
Nobody seems to have a simple answer.

4 Comments

The answer is very simple but most people explain it much more difficult.

You have to over expose your shot about 1 1/3 to 1 2/3 stops as you would normaly do.

It's good to use zebra at 70% to check your subjects skin tones. They should be around this value if you shoot SLog3. The reason for the noise is that you underexpose. SLog3 loves light so give it light. Shouldn't be a problem with the A7S II.

This also the reason why the native ISO for SLog3 is 1600. If you over expose this way it's more like ISO 400-500 and that's very agreeable with NDs.

It's all right if your image looks a bit blown out in camera but if you grade it the brightnes will come back to normal because most CC/grading is making the image darker than it was before.

April 23, 2017 at 10:34AM

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Eric Halbherr
Director, DP, Editor, Creative Storyteller
1940

If you can't re-shoot it try using neat video or other noise reduction tool, but like Eric suggested A7s's best used overexposed. Esp. with Slog you could recovere highlights better compare to shadows.

Keith Kim

April 27, 2017 at 1:37PM

My experience with the A7sII is very minimal, but I had an issue with a bug during a shoot once. It introduced major noise in Slog3 when shooting in certain ISOs.

Here is a discription from a different post about the bug: There's a bug on the a7sII in the 1600 - 10000 ISO range when filming in slog3 that adds additional horizontal noise / artifacts. Unfortunately it also affects hdmi out and is a known issue to Sony so hopefully a firmware fix will come out soon.
Here's an example of how to witness this bug -
Start in a dimly lit room with PP9 (slog3) on. The horizontal noise may not be terribly visible here but it's there. Increase your ISO up to 8000. This should really accentuate the artifact and your footage will look pretty terrible. Bump up to 10000 ISO, it will still be there. Now go up to 12800 ISO, and BOOM, that horizontal artifact disappears and the image is relatively clean. Drop the ISO back down to 10000 ISO, and it will still be clean. Drop it again to 8000 ISO and the horizontal artifact comes back. Bump up again to 10000 ISO and it will still be there. Bump up again to 12800, and it's clean.

It may be fixed in firmware these days, but maybe you are still rocking older firmware and are running into this problem. Maybe not - in that case, ignore this post.

April 25, 2017 at 7:11AM

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Jeroen Rommelaars
Animator - Videographer - Motion Tracking
1005

For many jobs, the 'fix' is simple: get an external monitor that lets you load in a LUT. Expose and shoot with it like that, so you see how your final image might look, not the washed-out super-bright image on the camera. In post, apply a post LUT. The A7SII can do very high ISOs very well- but Slog is meant for color grading. And yes, it helps to overexpose by a stop once you understand what your image will look like after grading. But use your histograms, etc., to be sure you don't clip.

April 26, 2017 at 1:17PM

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Patrick Ortman
I tell stories. Sometimes for money. Sometimes, not.
1006

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