Sony Fs7 MLUT Exposure Guide (and how to get that waveform to appear!)

I've had my Sony Fs7 for about a year now and I love the camera. Shot all kinds of things with it and love how versatile it is.

One of the first things I did when I got the camera was a few tests. I quickly found that I wouldn't be using Monitor LUTs (MLUTs) on the Fs7 EVF. This was entirely down to the lack of waveform. You might be able to expose by eye, I can't! Or more accurately, I don't trust my eyes :) The reason for this is simple. Your eye has an iris. In brighter conditions your iris closes, and the screen appears darker. This is why you see so much over-exposed exterior stuff where people are exposing by eye.

So I used my Odyssey 7Q+ when on sticks, and looked at the Slog when handheld - which was pretty horrible to focus! When I heard you could get the waveform up with an MLUT on the EVF (yes you can!) in V3 firmware, I immediately started using them, and have lived happily ever after. Almost... What I tend to do with the LUTs is find one I like and then get a healthy looking waveform, knowing that the Slog underneath will take care of itself. However, I've been going through several LUTs in the EVF lately and they all make exposure a little different. I wanted to do a quick test to see exactly where levels were with various popular LUTs and thought I'd share the results.

Tech Specs: XAVC I, Slog3.SGamut3.Cine, Full 4k, 2000EI. Light was an Arri Skypanel Daylight Remote Phosphor.

So I'm sure you all know how to expose your Fs7 Slog3 correctly. Personally I shoot at 2000EI 90% of the time and always have, even before noise reduction in V3. Not going down that particular rabbit hole (THE NOISE! WHAT ABOUT THE NOISE???!!!). If you want an in depth guide to exposing the Fs7, and all the techie stuff, I recommend The Fs7 Ultimate Exposure Guide. $10 well spent!

Just in case you have no idea where to expose Slog3 - Middle Grey should be at 41% and Bright White at 61%.

Note: One of the reasons I wanted to do this test was a discussion I had with a fellow cameraman. We were doing a multicam shoot and we used the Rec709TypeA LUT. I thought we should expose a little higher and he pointed out white level should be 71%. That rung a bell and I've since checked and that is what the official literature says. However... If we're talking about the white square on a colour chart (which I use as white), then I think 71% is too low. How dare I!!! You might use a pop up thing where the white isn't quite as reflective, but as you'll see, the wee white square hits 61% - so that's what I take as white in my crazy world!

So please keep in mind that this is based on my results, in a real world test. Levels are based on what I'm interpreting from the waveform (and what I think is white). There's a table at the end with my findings.

First up, here's the Slog3.cine

You can see the white tile on the colour chart is at 61%, exactly where it should be and middle grey is as bang on 41% as I could get it!

LUT: Sony LC-Rec709TypeA

Sony LC-Rec709

Screen Shot 2016-04-20 at 11.11.07.png

Sony Rec709(800)

And here's a table with my interpretation of levels from this test. Not official!!!

What this kinda shows is that regardless of your MLUT choice, if you put middle grey around 40-45%, you'll probably be pretty good with your exposure. Whereas white levels shift around a lot more. Why I'm a middle grey man :)

Now quickly a word on how to get that waveform up with MLUTs enabled. You must do these things:

1. No Waveform in S&Q mode

2. Lens Correction Off

3. SDI2 and Viewfinder MLUT On

4. Video Signal Monitor ON

5. If shooting full 4k, Output Setting must be 'Letterbox'

Ahhh, Sony simplicity! :)