Does S-Log need to be graded all the time?

[Dave Sperling]

Michael,
Would highly recommend using an external recorder - preferably one that is 10bit.
Remember, the 8-bit images on the SxS cards can be graded pretty well as long as you aren't stretching them too far.
S-log by its nature requires a greater level of adjustment of the image in post, hence possible problems in flat areas that have slight tonality ramps.
Try your own tests with a mid-tone wall that is not quite evenly lit. Or shoot a magic hour sky. Do some camera moves, then try some color correction on the s-log data and see if you get banding.
It should be better if recorded 10bit 422 or 444.

[Michael Carmine]

Well I did the homework. Yes the banding is 2x worse in S-log 8 bit but there is banding in cinegamma as well. The cinegammas look like cartoon colors and I can use this for the Disney sitcoms which want that primary color look. I guess I am forced to get another box to attach. The EI mode has great dynamic range over the non-EI mode and I am not sure why non-EI is even a option. I almost feel like 35mm film from 2 years ago. I am very disappointed in cinegamma color and have to come up with a matrix flat or negative color. Does the WiFi feature allow you to control the camera from a iphone for crane and camera cars?

[Vincent Oliver]

Originally Posted by Doug Jensen

Hi Alister,

As you have suggested, I expose for white and then everything else falls into place. It's not like I can expose for whites, midtones, and blacks separately. There can be only ONE exposure, and I base that on whites. I've learned to resist second guessing the exposure by what I see on the viewfinder or LCD and to rely on what the zebras are telling. 99.9% they will be right.

There is one very obvious problem with exposing for white. White is not always 100% white depending on the lighting conditions, take for example a white Vortex card in sunlight, this will be a different shade of white in the evening. I am not referring to colour balance here, just exposure.

Ansel Adams developed or should I say mastered the Zone system of exposure and he would base his exposures on a known white/grey (gray) value. But the problem was that under different lighting that grey or white was not consistent. He evaluated a scene and used his experience to meter white as is was seen at that time of day. Hope this makes sense.

So Doug if you base your exposure on a white in subdued evening light then you are in effect going to cancel out the ambient mood, you will produce an exposure which is technically correct for white, but will kill the ambient atmosphere,

Personally I use a combination of zebras, a well setup LCD screen, a Vortex white card and a frequently calibrated monitor. I am still working on how to employ the Zone system to video.

[Alister Chapman]

Originally Posted by Michael Carmine

The EI mode has great dynamic range over the non-EI mode and I am not sure why non-EI is even a option.

That should not be the case and is not my experience. All EI mode does is lock the ISO to 800 and then add gain to the LUT's and monitor output instead of adding gain at the camera head. Non EI S-Log at 800 iso and EI S-Log iso should be output exactly the same signal over the A/B outputs, there will be no difference in dynamic range. Non EI os an option for those that want to add gain at the camera head. There may be some advantage to adding in camera gain as it is pre processing, so if recording compressed may be cleaner than adding gain in post.

[Vincent Oliver]

I must confess that I have only just discovered what S-Log is all about. I am in two opinions on this. Yes, the higher dynamic range will allow more scope for tweaking and indeed capturing detail in both highligh and shadow areas etc.

However, from my own experience, unless your client has their TV, monitor setup correctly, you might as well shoot on any Standard setting. The same hold true for audio. Many times I have worked on a TV production and the director stops the shoot because of a distant sound, car or plane etc. Yet, in an average houehold, the dog may be barking, a lorry drives past your home or any one of the hundreds of other unwanted sounds creeps in.

The point I make is , are we being over concerned about a slight loss of detail in the highlights?

Don't get me wrong, I too strive for perfection in everything I do, but can become obsessed with trying to achieve perfection, when it may not be needed or appreciated.

[Charles Papert]

Having been forced to match s-log and non s-log footage from the same scene (due to pre v1.3 firmware that didn't allow for 60 fps capture with s-log), I would say the differences between the two are far from "slight". I like the images from the F3 with s-log. I don't particularly care for them without. For me it's not about satisfying a client, it's about capturing a look that I have in mind and having flexibility in post to be able to manipulate values as I choose.

[Nate Weaver]

Originally Posted by Vincent Oliver

The point I make is , are we being over concerned about a slight loss of detail in the highlights?

Not myself. I understand where you're coming from, I've been on plenty of shoots where somebody will latch onto one thing and try to make it unnaturally perfect for no good reason...

But badly burned highlights are a distraction in my book...and the F3 is not terribly good with them in the standard/Cinegamma profiles.

I myself am not overly concerned with detail and latitude for the sake of either, I just want my highlight burnouts to please the eye. Like on 35mm. Like on an Alexa. Like on a Canon DSLR. S-Log is the only way to get that I've found on the F3. Having the latitude to go with it benefits the image in other ways.

[Mark McCarthy]

I have just had my first test using S-LOG filming my son relaxing after school. What do you think, I am sort of happy with the results though I may have been half a stop to open. It seems really easy to over expose slightly. Focussing seems a little more tricky as well as you are focussing on something with less light /exposure - if this makes any sense! Here is my test:

First F3 S-LOG trial on Vimeo

[Chuck Fishbein]

Mark,
Looks nice for a first test. Curious as to what you used to grade your work.
Color, Colorista, Avid, Prermier or FCP internal color correction?
Care to share?
Thanks

[Mark McCarthy]

Thanks Chuck. I used Sony Vegas (have been using Vegas for 9 years now!). I just altered the levels (brought them up) added some saturation, then a little colour correction. These three effects, in this order, seem to work with my S-LOG footage. I don't know how many other S-LOG users use Vegas, but I haven't heard from many. I didn't play with the color curves with these clips but I think they look pretty good. I just think they may be half a stop over exposed. I am looking forward to trying out some shots in bright conditions. From what I gathered in the forum, you should only let the brightest part of any shot reach 80% on a waveform monitor and keep skin tones (on average) around 45. Would this be about right? Or this limited the dynamic range? Thanks for feedback, it's a real learning process for me. Sparky

[Doug Jensen]

Originally Posted by Vincent Oliver

There is one very obvious problem with exposing for white. White is not always 100% white depending on the lighting conditions, take for example a white Vortex card in sunlight, this will be a different shade of white in the evening. I am not referring to colour balance here, just exposure.

Hi Vincent,

I respect that you have a different approach, but my method of nailing the exposure via zebras has worked well for me for about 30 years. So, even if you think it wouldn't work and would destroy the ambience of the scene, I have to disagree. Underexposing is rarely the right approach no matter what the ambience is of the scene.

An exception would be if I was shooting a night time dramatic scene where I really did want my video to be very dark, but that is not what I shoot.

[Vincent Oliver]

I can see the point of using Zebras, and do so myself. My concern is that we can become too dependant on instruments that measure exposure or colour temperature etc. Sometimes our own eyes and judgement skills are the best instruments.

I am sure that after 30 years experience with video you don't need your Grandmother teaching you how to suck an egg.

[Doug Jensen]

Quote; "Sometimes our own eyes and judgement skills are the best instruments."

That is true if you are talking about naked vision into the eye. But with video, the light is going through the camera first and then being represented on a display that isn't your eyeball. I have learned that you often cannot trust what the viewfinder or flip-out LCD is telling you about color or exposure. No matter how well they are setup, the ambient lighting conditions where you are shooting will affect your judgement of what those displays are telling you.

I don't feel like I am too dependent on instruments. And I hope the pilot of my next flight doesn't decide to ignore his instruments and fly the plane by instinct because he knows better. And I hope my audio tech doesn't decide to ignore what his level meters are showing just because he thinks it sounds fine in his headphones.

There are good reasons why video professionals have used scopes, zebras, histograms, etc. for decades. And photographers and cinematographers have used light meters for more than a hundread years.
Scopes are better than your eyes and will not lie to you when used properly.

Making decisions based on what the LCD or viewfinder is telling you, will put you on the road to disaster. Not everytime, but often enough that it is a bad habit.

[Charles Papert]

I think one problem with this discussion is that we are talking about living and dying by rules in a an area that has room for rules to be broken, depending on the circumstances and what style of shooting one does.

There is a logic in assuming that the goal is to fit skin tones into a specific area of the exposure curve, with whites falling into their own place. The result of that is going to be a consistent and respectable image which is exactly what is required of many types of jobs (and will deliver the most range for post adjustment). It's what I would define as a "video" approach to image acquisition.

Conversely, with a "film" approach, the choice can be made to peg these values elsewhere. Rather than attempt to preserve the highlights from a window, one may opt to let them blow simply for the look (one example would be having to paper and light windows for day in a night or studio environment--you don't want to preserve detail of any kind for it to look real, the windows NEED to approach or enter clip to sell as daylight). And there may be times that one may want skintones underexposed as a dramatic choice. There is a big difference between exposing skin two stops under vs exposing "properly" and then attempting to darken them in post--at a certain point it just looks artificially suppressed in the latter circumstance.

This is by no means a indictment or endorsement of either style of shooting. I'm not a fan of the phrase "horses for courses" but it is applicable here. Video has always required a more delicate and precise hand with exposure than negative film due to the limited dynamic range, which resulted in adherence to rules to produce consistently good results. I personally rebelled against this and pushed and pulled it six ways to Sunday; sometimes it worked and sometimes it didn't (certainly with analog video it was far tougher to mess around with underexposure and avoid the whole thing sinking into murkiness). But if I was hired to deliver traditional, clean video, then by gum I toed the line and observed the zebras and fanatically avoided overexposure as Doug and Alistair have outlined here.

We have now the blessing of log and raw video which allows for a much more filmic approach if that is desired. And this gives us the opportunity to make creative choices, to break the "rules". Properly exposed video is no longer an absolute; it's a choice. Clipping is no longer a dirty word--if you want your highlights to blow, you can do so without them looking "electronic" (well, there's still a little way to go on this--it's still possible to get rogue color tints in overexposure, but so far I've been able to manage these in color correction).

Another way to consider this is whether one is acquiring the image or creating it. If the former, the goal is to find the single exposure that will deliver the greatest range of tones in the image and that, again, is what Doug and Alistair are describing (I hope--gents, please don't let me put words in your mouth if this is not accurate). In the latter circumstance, one has control over the individual exposure of everything in the frame and thus all are a creative choice.

I would submit that those seeking a specific answer to how to expose in log read as many opinions and watch as many "test videos" as they want, then turn off the internet and proceed to shoot a lot of tests for themselves. Take the footage into color correction and experiment. What is the difference between underexposing skin tone in camera vs knocking it down in post? Which delivers the look you are going for? Experiment, make mistakes. This is how we all learned to shoot before there were blogs and message boards.

[Alister Chapman]

Could not agree with you more Charles.

Exposure is subjective at the end of the day. With S-Log the way it over exposes is not unpleasant, so in an extreme lighting situation, or where that is the look you desire, then you over exposing is not the terrible sin that it was in the past.

However, if you are going to over expose or allow your highlights to blow out, make sure you have discussed this with the director, editor, colourist and however else is might be paying your fee, as once you do it, there is no going back. Of course sometimes you may find yourself in a lighting situation where it's unavoidable and it's then that your own skill and knowledge of how you over exposure is going to behave that becomes critical as you balance blown highlights with under exposure and try to find that optimum balance that the colourist can get the most from.

One issue with zebras and S-Log on the F3 is that Zebras don't go down low enough to be useful for anything other than your whites which if "going by the book" will be at 69IRE. Mid grey and skin tones are below the minimum F3 zebra levels.