Monitoring S-Log color

[Leonard Levy]

I tried posting about this on DVXUser and no one replied at all so i figured I would try over here.

I just got S-Log and am wondering how people are monitoring it. My concern is getting an image that my Client can make sense of and will also be useful to me for lighting, set-dressing etc. I've read many people suggesting that it should just be used like film and basically to forget about getting a decent monitor image, but for many reasons esp for clients I would prefer to get something close.

I've tried the LUT's and they all look as unsaturated as S-Log itself just with less DR. Kind of pointless to me. Lack of color is my main issue. Can you add saturation to a LUT? I looked very briefly at Sony's CVP file editor but didn't seem to see a control for Saturation.

I have been playing around with just cranking the Chroma way up on my monitor and that seems to be a pretty good solution. So far it looks pretty similar to what I get in post after grading. I've also played around with expanding the brightness and contrast which also seems to help though its easy to start losing highlights.

Is anyone else doing this? The idea is just to get in the ballpark.

Related issue is the idea of living with just a 3200 or 5600 preset. I've been playing with the S-Log color adjustments and find that they seem to work just like color pots on a paint box. Adding equal amounts of + Red and - Blue looks very similar to warming color temp and vice versa. Likewise +Red and +Blue can get rid of green by adding magenta. Pretty easy really . Seems like it will be simple to find numerical equivalents to CC filters. Also seems like it would be easy for Sony to make these color temp and phase adjustments in firmware.

Why not try to get a half decent picture in your monitor when using s-Log, and why not start off with your color near your final target. Shouldn't that provide a better grade?

Is anyone else doing this?

One last question - Any tips on grading S-Log in Final Cut Pro (old version 7)? I've been playing with the usual tools and it is a little frustrating to get stuff right. Can't use Resolve on my MacbookPro unfortunately. I downloaded a trial SLog filter from Pomfort, but at first glance I wasn't bowled over..

[Nick Hiltgen]

Pick up a blackmagic hd link box and load (or create) a rec709 lut on it, this will turn the slog into a more consumer friendly version of the footage while maintaining the robustness of s-log. just did it on a music video and it worked great.

[Doug Jensen]

Leonard,

Go back and read your post. Now ask yourself why you are even using S-LOG? I have found that a good Picture Profile using the Cine Gammas solves all of the problems you are experiencing: WYSIWYG when shooting. A great image on the monitor for clients. No need to struggle or spend time color grading. No need to wait for renders or archive another copy of your files. No need to learn new color grading software. And no need to risk someone else misgrading the footage after it has been handed over.

And for that one shot in a hundred where the extra little dynamic range of S-LOG might have made a difference, I am willing to let that slide. The trade off is well worth it in my opinion.

Am I hack for not drinking the kool-aid and blindly using S-LOG? Some people will say that. But I don't care. I have done my own testing and I know how much more effieicent and productive I can be without S-LOG. And I will be more than happy to do a side-by-side shoot out with anyone who thinks S-LOG is going to make a big difference against a properly setup camera.

I'm not saying S-LOG isn't a terrific tool for the right production, but it's not the right choice for everyone. Some people seem determined to cram a round peg into a square hole even though there is nothing at all wrong with using a square peg in the first place.
Just another point of view.

[Douglas Villalba]

I don't have the S-log option, so this is just another opinion.
As I undertand it S-log's ISO equivalent is 1600. Are you by any chance over exposing and that is why you are not seen the color when setting the SDI Out to 709-800%?

[Leonard Levy]

Thanks Nick, HD Link is am interesting idea though frankly I am very tired buying more and more accessories these days.

Re Doug and Douglas- I'm running my own tests and will decide when and if I want to use sLog rather than cinegammas. It certainly seems that in some situations it can offer a great deal. In the meantime I just want to figure out how to work with it in an efficient way, and am trying to open up a discussion about how to monitor it most effectively.

So I'm curious, is anyone offering decent user made LUT's for the F3?

[Doug Jensen]

Originally Posted by Douglas Villalba

As I undertand it S-log's ISO equivalent is 1600.

Not according to my testing. S-LOG is more like ISO 1000 if you want to put mid-gray around 38% and whites around 68%.
BTW, with my primary picture profile it's only 250 when exposing whites around 98%.

[Alister Chapman]

If your putting reflected white at 98% and coming up with 250 ISO, then I believe that to be incorrect. If your estimating exposure equivalents to film and using a light meter, then white should still be 68%, which would equate to an ISO closer to 400.

[Doug Jensen]

Originally Posted by Doug Jensen

BTW, with my primary picture profile it's only 250 when exposing whites around 98%.

Originally Posted by Alister Chapman

If your putting reflected white at 98% and coming up with 250 ISO, then I believe that to be incorrect. If your estimating exposure equivalents to film and using a light meter, then white should still be 68%, which would equate to an ISO closer to 400.

Alister, please notice that in this sentence I am talking about my primary PICTURE PROFILE not S-LOG. There are no picture profiles with S-LOG. If I exposed white at 68% with a PP, and didn't plan to do any grading, I'd be dramatically underexposing.

When using any picture profile I expose whites around 98%, sometimes a little less. I assure you that my F3 would be rated at ISO 250 using my primary picture profile -- not that this number matters very much because I'm not going to be setting my exposure based on a light meter reading. I find it interesting that you are telling me 250 is incorrect when you don't even know what my picture profile settings are.

Of course, when using S-LOG a whole different set of procedures and preferred exposure levels apply, but that is not what I was talking about.

[Brian Lai]

Hi Leonard,
My BG is film and my exposure methods will seem archaic comparing to most everyone on the forum who judges exposure based on where IRE measurements ought to fall for mid grey, skin tone and highlights. With the LUT set on .709, I used both incident and spot meter measurements exposing a grey card w/color chart based on 1600 ASA sensitivity, and judging side by side with both a Panasonic 17" with a scope and a larger consumer Samsung (with its brightness and picture level set below mid point), I tweak the Samsung so both monitors display almost identical images and extremely close to WYSIWYG. I'm a convinced that the 1600 ASA hold up based on the presumption that most home monitors will be set brighter and more chromatic than my monitors, thus will most likely display my color chart and grey scale perceptively brighter and more chromatic than the 18% mid-grey reflectance based on a film exposure approach. Final grading on LightWorks and TV Logic monitors at a local post house confirms my Flintstone's exposure approach is within 'mid printer lights', as film parlance goes.

On the monitoring issues, I stay with LUT .709 on the monitor until camera rolls before switching back to Log. The irony of it all is that we are all falling in love of the slightly de-saturated look of S Log on skin tones and grade our final color correction closer to Log than .709 (which I don't perceive as chromatically flat, but that's very subjective) and of course if you're after high key, high chromatic Kodachrome looks you may not want to bother with S Log at all. I use it because I can pull details out of a face that is 4-5 stops over exposed. Cranking up chroma and contrast on your monitor may give you the ultimate look you desire but I imagine it maybe difficult to maintain a constant & consistent correlation as chromatic values of your subject change but the monitor may not deliver the exact equivalent once cranked up.

Just my two cents worth.

[Leonard Levy]

Brian,
Sounds like you are exposing based on the 709 LUT not not trying to peg a grey card at 38% in SLog.
Is that 709 800% or 108%?

I have thought of that, but find even the LUT's way too desaturated compared to a real 709 image. Also I like seeing the sLog on a monitor because then i can really see exactly how my whites are holding up, and to some extent expose accordingly - but its all a grand experiment at this point.

So far I've been surprised how well the "crank up the monitor" solution works and how well I can tweak color with the R/B adjustments. I've only tried it on my Flanders so far though, and as with your method the goal is only to get it in the ballpark.

I would much rather have LUTs I liked though than to have to keep screwing around with the monitor. Presets are a pain even with the Flanders.

For me SLog sounds like a godsend for Ext run & gun without time to control the light. I rely on lot on a 5.6 TV Logic or a SmallHD EVF there and haven't experimented with cranking those guys yet.

Anyone else find the LUT's too desaturated to use? Am I alone in this?

[Doug Jensen]

Yes, all the built-in LUTs are really ugly. But the problems with them go beyond just the saturation.

[Leonard Levy]

What other problems do you have with the LUT's besides saturation.

[Brian Lai]

Leonard,
I monitor with .709 108% for more saturation. .709 800% looks even flatter. I don't think I put my exposures 'in a ballpark', it's just my way of calibrating the monitors - seeing the grey card and color charts on the monitor looking exactly as my eyes perceive, at a determined ASA & exposure based on matching readings from incident and reflected spot meters, using a single light source corrected to the exact color temp. the camera is recording on. This is my 'constant' and where I rely on making exposure decisions afterwards. It's like establishing printer points in film days with a monitor. Flipping back to S Log just gives me the comfort of knowing it's recording with more latitude & dynamic range (if needed) and I can surely grade it from flat to super chromatic afterwards.

I take monitors with a grain of salt, given that you can line up 10 identical monitors shooting the same subject, there will still be minor variations in looks due to the nature of the beast, and we certainly have no control over the viewer's home monitor when the finished work is displayed, unlike projection a film in a dedicated theatre where the projector's luminance, color temp. and reflective quality of the screen is within our control.

You're right it's still an experimental era in Log recording and Alister is the expert to go to having explored exposure on a different thread earlier.

[Leonard Levy]

Brian,
Do you not use the waveform monitor in your monitor? That's much more reliable than judging anything by picture quality exposure on a monitor as that can be way way off. So far I've been using the camera's IRE readout on a greycard to hit 38%, but I won't always have one.

You're using the 709 LUT though instead of the Std 5 - 709 picture profile which would be another way to go with better saturation , but perhaps a different exposure.

[Duke Marsh]

Originally Posted by Doug Jensen

<snip>
And for that one shot in a hundred where the extra little dynamic range of S-LOG might have made a difference, I am willing to let that slide. The trade off is well worth it in my opinion.
properly setup camera.
<snip>
I'm not saying S-LOG isn't a terrific tool for the right production, but it's not the right choice for everyone. Some people seem determined to cram a round peg into a square hole even though there is nothing at all wrong with using a square peg in the first place.
Just another point of view.

Doug, there are far more benefits to S-Log than dynamic range. The roll off on highlights and blow outs comes to mind. I love the regular F3 images, but if you have a practical light come into the scene you usually have an ugly yellow ring around a blow out that simply looks unnatural and video-ish.

As for speeding up production, with picture profiles you save a little time on grading (I think most footage can use a little tweaking for maximum effect) but unless you're in an ENG situation not too much time is saved.

That's because if you are grading many clips you simply copy and paste the attributes to the next clip. If they were shot in the same room at the same time little to nothing extra needs to be done on the subsequent clips (until you have a reverse shot, etc.)

OTOH, S-Log can also speed up your production by allowing you to shoot in situations where you have a lighting situation that picture profiles can't handle. That especially applies to live events where you have little or no control of the lighting.

Finally, as much as I like the skin tones when using F3 picture profiles, I like them even more with S-Log. Shiny highlights are less of a problem, back lit faces are manageable, shadows can be worked around. Sure if you're shooting talking heads those issues rarely arise, but if that's all you're shooting an EX1 is just fine.

S-Log isn't perfect, but the advantages are real. Its that extra 10% that I get out of it that I love about it. I used it on my last two features and one TV show and will never turn back. When someone is paying big money for cast, crew, etc you can't afford to miss a shot. Period.