Is S-Log Really Worth It?

There are a lot of opinions out there about S-Log3: people who say S-Log3 is too noisy, especially in low light. People who say the image is too flat and milky or there isn’t enough contrast; I can’t see if my white balance is correct when I’m shooting; it’s not really worth it since the a7S II is an only 8-bits instead of 10, and as a result you get horrible color banding; Sony only added it to the Alpha line as a marketing ploy, etc. etc.

So today I wanted to share with you my experience with shooting S-Log3, and then we’ll take a look at some test footage I shot, and then some actual wedding footage I shot using S-Log3.

So, when I first started shooting on my a7s II, I did a little bit of research, and the picture profile I ended up shooting in was Cine 1 with a color mode of Pro.

Now, a lot of you guys out there will probably be saying, “Why wouldn’t you shoot in Cine4? It’s clearly the best.” 

And the reason I went for Cine 1 instead of Cine 4 was because of my color grading workflow. I’m a big fan of color grading with FilmConvert inside of Final Cut Pro X, and FilmConvert has color profiles for the Sony a7s II with Cine1 Pro. That gave me a really good image in-camera that if I wasn’t able to grade it at all, still looked great, wasn’t too flat, but also gave me the ability to add some grading and achieve a more cinematic “look” if I wanted.

But I always felt I was missing that really beautiful Sony “look” that I was seeing in so many other videos and wedding films. And I always knew S-Log3 was out there, but I had heard so much negative stuff about it, that I was never really too keen to try it. But, eventually, my curiosity got the best of me and I decided to head out to the Waterway in Houston, TX and get some test footage.

But before we get to that, let’s talk about what a log format is.

In a nutshell, recording using a log picture profile or curve preserves more of your image’s dynamic range and tonality by redistributing the digital exposure value representations over the entire value set using a preset logarithmic function.

Wait, what?

So, simply put, a log format is just a certain set of math applied to your image, or more specifically to the tonality curve of your image, when you shoot, with the goal of preserving a greater dynamic range than a normal or “linear” color mode. When cameras starting becoming capable of capturing a greater dynamic range than televisions (or computer screens) were capable of displaying, formats such as Log formats began to emerge in order to give the post-production colorist more control over the exposure after the footage was shot, instead of just sticking with the exact same dynamic range of the TV the footage would be displayed on.

Log is short for logarithm and S-Log is Sony’s log format, hence the “S,” If you have a DJI drone like the Phantom 3 or Phantom 4, or the Mavic Pro, or another DJI product like the Osmo, you may notice the ability to shoot in D-LOG, which is DJI’s LOG format. Panasonic has their own log format called V-Log, and so on. Different companies all have their own take on what they believe to be the best log curve to maximize dynamic range for their cameras and their sensors.

Now, all that being said, shooting in log formats can give you more dynamic range, but color correcting is going to become a must if you want to have any footage that’s usable whatsoever. Log footage, straight out of the camera, is incredibly low-contrast and unsaturated, almost black and white.

So, if you’re just looking to run and gun, shoot something and have it look reasonably nice right out of the camera, shooting in a log format is not going to be for you.

But, if you’re reasonably comfortable with color grading your footage, shooting in log can give you a lot more options in post, and end up producing some beautiful images. 

So you may be wondering to yourself, “So Steve, if log formats are so incredible, why do people talk so much shit on S-Log3?” Well, one answer to that is this: your color format, like S-Log3, may be fantastic as far as retaining dynamic range, but ultimately it’s going to be limited by other things like your camera’s bit depth and codec. The Sony a7S II, being an 8-bit camera, doesn’t have as many colors available to it as a 10-bit camera, like for instance, the Sony FS5. So if you grade it heavily, you might get some color banding. 

Or people say S-Log3 is way too noisy, and that’s because when it comes to S-Log3, the trick to properly exposing is to actually overexpose by two stops, to allow the logarithm to work its magic and capture as much dynamic range as possible. (Pro tip: on the Sony a7S II, the light meter tops out at 2 stops overexposed, so a good practice is to keep the exposure about +1.7 to make sure you’re getting the most bang for your buck).

Another thing worth noting is that if you’re shooting in S-Log3, your minimum ISO is going to be 1600 and your camera will not let you select anything lower than that. That means if you’re shooting outside in bright conditions, you’re almost definitely going to want to use an ND filter, but that’s something we’ll cover in another video.

Another pro-tip for shooting S-Log on your Sony camera is using the Gamma Display Assist function. Since the image can be so flat, so low-contrast and under saturated, it can be hard to judge things like your white balance or even your exposure. Turning on the Gamma Display Assist  function can be a huge help as it shows you what your log image would look like in a Rec.709 color space, which is ultimately what you’ll be doing when you color correct it in post.

So what's the verdict? For me, my workflow, my color grading process, S-Log3 gives me the most flexibility in post. Does it get a little noisy sometimes? Yes. Do I get some color banding sometimes? Yes. Is it within an acceptable range of image quality? For me, the answer is yes. The Sony a7s II is a powerhouse of a camera, especially in something so small, and to be able to achieve such a cinematic look, for me, I can deal with the banding and the little bit of noise from time to time. And, if whatever camera comes next from Sony, be it an a9S or an a7s III, if we can get 10-bit color depth, shooting in S-Log will be even better. So there you have it!

As always, if you guys have any questions or comments, feel free to leave them below!