F3: F3 S-Log Exposure and LUT

J

jamesharding

Member
Hi everyone,

I don't own an F3 and have never used one, but I am keen to rent one for an upcoming film. I've never filmed with S-log before so I was wondering if you could answer a few questions for me. The camera will have firmware 1.4 without the RGB unlock (the one that gives you full capabilities)

1. How do you expose the F3 when it is in S-log mode, and how do you do it using a light meter
2. I believe that an unlocked F3 cannot do LUT's for s-log, but can you create a picture profile that emulates a LUT and switch to and from? Or is there a better way to see how your image may look?

Thank you, I'm sure these have been answered a hundred times before but I am renting soon and I can't find the answers to my questions so far.
 
Hi James, welcome to DVX and the F3 section.

What cameras have you worked with in the past? I'll see if I can draw any parallels or differences.

In the meantime the quick answer to exposing SLOG is by simply using a grey card to read 38%IRE and a white piece of paper to read around 68%. This is because in SLOG mode the camera squeezes down the entire tonal range of the sensor so that later in post when you de-SLOG you are getting more data throughout the entire tonal range needed for a good grade.

Without the paid RGB upgrade you do not have RGB 444 or LUT capability you are correct. Images will look whitish and lack contrast on screen, but oddly you can get use to it if you shoot with it long enough. You can get an external monitor that can do some adjustments as an option as well.

As for switching to and from a picture profile, I did create a modified picture profile that would allow you to use the profile to view your scene in-camera normal in appearance, and then when you're ready to shoot you would switch back to the SLOG profile but I have to dig it up. I made one for someone else here a while ago and now have no idea where I put it.
 
jamesharding said:
Hi everyone,

I don't own an F3 and have never used one, but I am keen to rent one for an upcoming film. I've never filmed with S-log before so I was wondering if you could answer a few questions for me. The camera will have firmware 1.4 without the RGB unlock (the one that gives you full capabilities)

1. How do you expose the F3 when it is in S-log mode, and how do you do it using a light meter
2. I believe that an unlocked F3 cannot do LUT's for s-log, but can you create a picture profile that emulates a LUT and switch to and from? Or is there a better way to see how your image may look?

Thank you, I'm sure these have been answered a hundred times before but I am renting soon and I can't find the answers to my questions so far.
Click to expand...

Hi James,

As Dennis said, for SLOG exposure use the spotmeter on the F3 to either expose a grey card at 38% or a white card at 68%; or you can rate the camera at 1600 ISO with a lightmeter (which should yield middle grey at 38%) - test your meter to confirm this though.

As for LUTs, you can't do them without the RGB upgrade unfortunately. I find the key to working with SLOG without LUTs is to simply focus on your exposure, composition and WHITE BALANCE, and don't stress about the colour at all - if you're recording 10-bit 4:2:2, it's ALL in there.

White balance is hard to judge with SLOG, so update it every time your lighting situation changes.

Nail exposure and white balance though, and the footage will look beautiful. Just trust that the colour is there (even though you can't see it whilst monitoring - it'll be there in post).
 
To add to Dennis's advice, I also set one zebra for 55% and adjust exposure so skin highlights(foreheads) are barely registering 55. From that same exposure, if I immediately test the shot with my 18% grey card, its usually with 1-4% of 38%IRE.
 
Yes I forgot to mention the F3 has a built in spot meter so even though I am often using a lightmeter while shooting I'm often using the built-in spot meter to check up on certain scene values like shadows, skin levels, grey card, and also white surfaces. Just hover the small box in the center of the camera over the area you want to measure.

As Grug pointed out in SLOG mode you can rate the F3 at 1600 but NOTE that's only if the camera is in 25p, 1/50th shutter, 0db gain mode. Anything else you would have to adjust your camera ISO rating accordingly.

A couple other life saving tips since you're probably not familar with the F3:

- When you first get the camera I recommend you do a factory reset. This is in the OTHERS -> ALL RESET menu.
- Then select your recording format, country format and frame rate: OTHERS -> SYSTEM ->
- Make sure the GAIN SELECT switch is on L (low) and make sure its programmed for 0db. CAMERA SET -> GAIN SETUP.
- Set your shutter to 180 degree or 1/50 shutter (for 25p) or 1/48th shutter for 24p.
- Setup your PEAKING function so you know when you're in focus. LCD/VF SET -> PEAKING. You turn it on and off from the peaking button near the LCD.
- Setup your zebras if you plan to use them. LCD/VF SET -> Zebras.
- Next create your picture profile using the SLOG gamma. Press PICTURE PROFILE button, select a blank slot (PP1 is good) then press SET. Find GAMMA and under there select SLOG. You can also dial in your white balance in this menu as well so long as the WHITE BALANCE switch near the LCD is set to "PRESET". You can manually white balance if you want too.

The rest you will figure out. :happy:
 
I find that I can get a fairly decent idea of color simply by cranking my monitor's contrast and saturation until it looks good. You have to remember though that it is just a guide for you and it depends how you use sLog. If you are white balancing or staying within Tungstun or Daylight parameters I find it helpful and you can adjust your monitor to what you think the final image should look like. Helpful for clients and to check general lighting especially off color light source issues.
However don't use it for exposure or to trust dynamic range - use the the advice in the posts above. Also it will generally burn out your highlights completely even though they are fine in your actual image.

Lenny
 
Great thread for all! Nice work.
I have come to really rely on the F3's spot-meter--great feature. Is anyone aware of monitor or recorder with on-board screen that offers the same? I know the FSI has it on their monitors, but it's a bit tedious in function.
 
Thanks everyone for your reply's, I feel you have given me a free workshop in the few lines of this forum so thank you! Starcentral (dennis), the camera I own is the Sony FS100, so I am hoping there are a couple of similarities, especially in terms of fiddly menus which I have learnt to love. If you ever find that PP that worked as a LUT I would be very greatful, I'm pretty happy I can work without it, but my producer will never have worked with a LOG camera so she might have a heart attack when she see's a washed out image from her £400 investment ;) Having worked on the FS100, I'm used to protecting the highlights at all costs so thanks for the heads up there. Thanks again and look forward to working with such a fantastic camera!
 
I use the spotmeter and follow the 38/68% rule when shooting S-log. Actually I find it so easy to shoot this way and honestly the 3200k or 5600k choices when in s-log mode works fine. F3 is not just a great camera with lovely images it's also pretty easy to deal with.
 
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