Category Archives: Expose

Solution to the Blue Clipping Problem?

Many have reported the dreaded blue clipping problem that occurs specifically with LED lights (doesn’t have to be blue LEDs), in which the blue channel “clips” to an ugly blue color. This doesn’t happen with all LED lights, but just a few specific types.

First, watch this super-quick video to see what’s happening:

Explanations

RGB Parade – I’m changing the white balance setting. Once I cross a certain threshold, you see the red and green channels drop. They don’t drop to 0 immediately, but in stages. So, the blue clipping is caused by the red and green vanishing, while the blue stays where it is. That’s why you see blue. When it’s overexposed, it is blue-white.

Vectorscope – This is the tricky part. You can see how the blue channel goes haywire, beyond permissible limits. Again, I’m changing the white balance and no other setting.

White balance – From 2600K to 4500K, the blue clipping problem can occur. Once I hit 4500K, the clipping goes away.

As you can see, it only affects the area in contact with the LED lights. The other regions continue to behave normally.

Since this only happens with LED lights, the possible explanation could be that since LEDs have a blue spike in their spectrum, for some reason this throws off the pixels (called sensels) in the Sony sensor (the same problem is said to exist in the FS700, FS7, etc.). The pixels affected are no longer able to collect red and green information, and the result is too much blue.

Solution?

I’m not sure this is a solution, and I’ve only been able to test it with the LED lights on the back of my LED lighting panel (it’s not a “blue” LED, it’s a white LED that looks blue. A blue LED is a specific type of LED that got its inventors the Nobel Prize a year ago).

If you’re in a club or street and you start to see blue clipping, you might have white balanced to a Kelvin rating below 4500K. Try to change the white balance to above 4500K. This will change the colors of course, but they can be corrected in post. The blue clipping can’t be fixed.

If I find something else I’ll let you know. If you do find a solution please share it and I’ll publish it.

Handy exposure cheat sheet for any situation

If all the picture profile tests were a bit too much, then this lesson will simplify it. Of course, it goes without saying that this exposure cheat sheet is based on my interpretations, some of which are heavily subjective.

But it’s a good place to start, if that’s what you want. Don’t hold me responsible!

Click to enlarge or right-click and Save As… to save:

HandyExposureChart

FAQs

These are important topics raised by subscribers that shed more light on this lesson.

Q. What do you do about blown-out windows in S-Log2?

A. What do you do about blown out windows in any mode? Sooner or later there will be situations that have too much dynamic range for the camera. Blown out windows and specular highlights will be problematic for the best cameras on earth.

As always, use your judgement. Sometimes you can gel the windows, other times you can use a grad/split ND filter to get it under.

If these are not options, you can overexpose less. But if you try to save the window by underexposing or even normally exposing, you will get ugly noise on your actors and in the shadows. This is the unique nature of the A7s in S-Log2. Luckily, the highlights blow out gracefully, almost as good as the Alexa.

A few months ago I tested this in my home with my wife, where she walks from a tungsten source (entrance) to the living room with a large window in a single shot, daylight balanced. Very bright outside. I could only get something acceptable by using a graduated ND filter sideways and cheating a bit.

Q. How do you match exposure with the A7s if your primary camera is another one, like the Alexa or Red Epic?

One solution is to NOT use S-Log2 for such shots, but shoot in one of the picture profiles. The camera has four cine profiles – Cine1, 2, 3 and 4. You can try each one to see if you like the look. Easier workflow, but not the best quality. I like Cine1 and use it when I don’t want to grade. Cine2 for low light. But it is a matter of taste.

Otherwise, you can also use ETTR on the higher-end cameras to match the 2-3-stop wolfcrow system on the A7s. Either way, the highlight roll-off on the A7s is very graceful, and will stand toe-to-toe with any camera.

But don’t ask for miracles!

Click on the link below to the next lesson or head over to the main menu (above). If you need help with something, feel free to send me an email. I’ll try to get back to you as soon as possible.

 

S-Log2 Exposure and Monitoring Workflow – the Wolfcrow System

This guide covers the S-Log2 workflow as it pertains to the Sony A7s, shot in S-Gamut color mode. We will learn:

  • How to expose for S-Log2
  • How to monitor exposure in S-Log2 using nothing but the camera
  • How to match shots and grade in S-Log2
  • Two ‘correct’ ways to expose, and which I prefer and why

The software I use are:

  • Adobe Premiere Pro – to edit my sequence and to export to Youtube
  • Adobe After Effects – my “former” grading tool of choice, sometimes with Color Finesse 3
  • Adobe Speedgrade – for the Annakotta (Elephant Fort) sequence – and my grading tool from here on out

List of articles you need to read before watching the video

Before you watch the guide, or read about the wolfcrow system, please make sure we’re on the same page about the terminologies used. Otherwise it’s going to be tough viewing. Here are articles that will help you understand the terms as I define them:

Also, please watch the fully graded Annakotta (Elephant Fort) sequence before you watch the workflow guide so I don’t put any thoughts into your head:

How to expose, monitor and grade S-Log2

Watch the entire thing if you can. It’s an hour long, but there was no faster way to explain how I arrived at the wolfcrow system. Here are some highlights, in case you feel like jumping ahead:

  • 1:10 Two ways to expose for S-Log2! The ETTR system and the wolfcrow system
  • 6:40 Problems with the ETTR system and why I don’t prefer it
  • 8:00 Understanding the difference between RAW and S-Log2
  • 11:00 Understanding S-Log2
  • 13:50 How the Zebras in the Sony A7s works
  • 17:40 How to use the Zone system to test for the usable Dynamic Range
  • 26:30 What is the real “middle grey” for the Sony A7s?
  • 29:18 How to expose for the best skin tones
  • 32:12 The wolfcrow system of getting the right exposure with the Sony A7s
  • 36:00 How to use nothing but the in-camera Zebra and meter for your exposures
  • 42:42 When and how to use LUTs
  • 49:40 wolfcrow system condensed
  • 52:50 How to grade S-Log2 footage from the Sony A7s

Here’s the guide. Enjoy:

Notes, Errors and Omissions on the the Video

I recorded the video during the night to avoid traffic noise, so I have made a few slip ups. Here are the ones I caught at the time of publishing:

Errors and omissions:

Apologies for the voice and lack of eye contact. It was hard.

In my article on full swing vs studio swing, I define full swing correctly, as between 0-1024; yet in the video, I use the term ‘full swing’ to mean full swing+super whites, which is incorrect. Please be aware of the difference, and it doesn’t mean anything in practical terms. In the video, when I say full swing, I’m always referring to full swing+super whites. This is the entire range from -7 to 109 IRE.

I mention in the article that 2+ stops is the least noisy, though evidently that is incorrect. It was a slip up. The least noisy is ETTR, and the wolfcrow system is the next best thing.

During the chart after the 11:00 mark, I show how a one stop overhead makes the dynamic range 12 stops. That is incorrect, and was a mistake I made while speeding up post. The 12 stops of usable dynamic range includes the overhead, all the way to 109 IRE.

Clarifications

Some clarifications, in case things are not obvious:

2 stops over is the middle point. Following the Zone system analogy, it would be Zone V. Middle grey, then, will be at Zone III.

References

I did make some bold statements during the video, and here are the references for the same:

I say that Kodak film has a usable dynamic range of 12 stops. It is from a Kodakwhitepaper (motion.kodak.com): Exposing Film. Some gems from it:

Generally speaking, the latitude of KODAK Color Negative Film is about 10-12 stops.

To obtain the best exposure, err on the side of over-exposure to create a “bullet-proof” negative. It’s better to provide too much information on the negative than too little.

The entire analog image chain is designed to accommodate a normal exposure, normal processing, and normal printing. In fact, the system is nearly foolproof and endlessly forgiving when everything operates under normal parameters.

Cinematographers usually operate very close to that line of normalcy. Small adjustments … can produce interesting outcomes that provide precise and repeatable control over a great number of image parameters.

This is the foundation of the wolfcrow system.

Always attempt to get the best latitude, grain, color and sharpness from the stock you’re using. A properly exposed negative will optimize all these characteristics. Once you understand the film’s limits and capabilities, you can be more confident while making tough, on-the-spot shooting decisions. Occasionally, you will deviate from the normal exposure.

Consistent exposure minimizes dependence on the laboratory’s ability to compensate; as exposure correction always results in a trade-off in some area of image quality.

About S-Log2, I mentioned it was designed for DI workflows. This is from S-Log: A new LUT for digital production mastering and interchange applications, by Hugo Gaggioni, Patel Dhanendra, Jin Yamashita, N. Kawada, K. Endo and Curtis Clark:

S-Log is a gamma function applied to Sony’s electronic cinematography cameras, in a manner that digitally originated images can be post-processed with similar techniques as those employed for film originated materials.

Shooting in S-Log will enable the cinematographer to decide the exposure value by using a light meter.

CMOS imagers respond to incoming light in a far more linear fashion than film, thus there are no “toes” or “shoulders”.

When shooting in S-Log, as distinct from ITU-R BT.709 (Rec. 709) video gamma, a color grading process (‘look management’) is mandatory…

About the relation of S-Log2 to white balance, and why it affects grading and the creation of LUTs, refer to Technical Summary for S-Gamut3.Cine/S-Log3 and S-Gamut/S-Log3, by Sony:

It [S-Log3] is more like a pure log encoding than S-Log2 to provide better log based grading.

S-Gamut needs color temperature setting to select color conversion matrix. S-Gamut3…does not depend on color temperature any more.

White point of S-Gamut is D65

S-Gamut is the color space when shooting S-Log2.

Mid exposure point or Zone V for the Sony A7s in S-Log2 mode

As mentioned in the video, the mid exposure point, or Zone V, for S-Log2 is 2 stops over. In other words, what should be middle grey should be overexposed by 2 stops:

Zone V for Sony A7s S-Log2

How to expose for best quality

Unfortunately, areas at the ‘defined’ middle-grey (32% IRE) still suffer from color noise (click to enlarge):

Color Noise at Middle Grey

The lowest level that eliminates color noise is IRE 40. For this reason, it is suggested to expose at 3 to 3 and 1/3rd stops over middle grey. This is the wolfcrow system.

A practical example of using the wolfcrow system

Here’s a quick and simple practical demonstration of using the wolfcrow system with lighting:

Important notes:

  • At one point I say lighting/contrast ratio is 2 stops, but it’s only 1.5 stops. However, that’s with a light meter. In the actual scopes, the difference is a full 2 stops because you can isolate the darkest and brightest portions. You can’t do that with a light meter.
  • Ignore the color tint for this video. I shot with the a7S, though the newer cameras have gotten rid of the green color cast in S-Log2. I’ve tested each camera separately, and I have additional videos in my guide for each of them. There is no difference between them as far as exposure for S-Log2 is concerned.
  • Shot at 3840×2160 Prores LT on an Atomos Shogun at 25 fps. White balanced to 2900K

If you’re not seeing any difference between 2 stops over and 3 stops over, here’s an image for you to study (red channel only, graded with raised levels in PS, click to enlarge):

Noisedifference2stops3stopsSLog2

Two points:

  • 3 stops over is definitely cleaner in the shadow side (look at the ear). It might seem like we’re splitting hairs, but –
  • Study the background. The background upper portion is 1 stop under key, and the lower portion is 2 stops under key. The noise is clearly and visibly greater at 2 stops over. This is the problem – you get okay results on the main subject, but if you have anything darker it will suffer. That’s why 3 stops over is better.

The wolfcrow system, in a nutshell

Here is a simple list that tells you how to expose S-Log2 using the wolfcrow system:

  1. Choose the most important parts of your scene (skin tones, objects, whatever) that would traditionally be at middle grey (Zone V, to be precise). Using a spot meter, let these areas by 3 stops over the meter rating.
  2. If using a reflective light meter for lighting, calibrate your light meter to be 3 stops over the camera meter. Then you can light as usual.
  3. Keep the base exposure at about 60-70 IRE. You can use a waveform monitor (in full swing mode, important!) to show you this. If you don’t have access to a monitor, use the in-camera Zebra level of 70, which displays the 60-70 IRE range.
  4. Since white balance is critical, try to custom white balance each scene using a white card. If you’re in a run-and-gun setup, and know you can’t white balance for every shot, then use Auto White Balance (AWB), since this will give you the least amount of work during post production.

Can it be any simpler? No it cannot. Here’s a quick infographic from the video that shows all this in a nutshell:

Wolfcrow System of S-Log2

The wolfcrow system vs ETTR

Finally, here’s a quick comparison chart between the two exposure methods. Both ETTR and the wolfcrow system are valid methods, though I prefer the wolfcrow system:

Advantages Disadvantages
Exposing to the Right (ETTR) Least amount of noise possible Can’t really expose using Zebras or the histogram, need a waveform monitor. 100+ zebra isn’t really ETTR.Color grading is extremely hard, and ETTR for RAW does not work the same way as ETTR for S-Log2.
The Wolfcrow System Combines the advantage of ETTR (zero color noise) while maintaining maximum tonality and texture – the fundamental concepts of the zone system.Provides a consistent Zone V point for easy color grading in post production – something that is mandatory with S-Log2.One can use the in-camera meter and/or zebra to expose, without needing any external tools.DPs can calibrate theirlight meters to a consistent level. You can light by eye! Due to inaccuracies in testing, zebras, meters, etc., individual operators must start experimenting with the Wolfcrow system and find their optimal exposure point. This is exactly how a DP would learn to use film. There is still a lot of subjectivity in exposure, which no system can cure.One must always have an eye on clipping highlights, though that is the case for any exposure!

That’s it. I hope you have found this guide useful. Please share your experiments with the wolfcrow system, or any other exposure method for that matter. In the coming year, I’m going to be using the wolfcrow system with my Sony A7s.

Maybe you will too.

FAQs

These are important topics raised by subscribers that shed more light on this lesson.

Q. How do you use zebras under the wolfcrow system?

A. I keep my zebras at 70 IRE so I can see if my main subject is at the right exposure. Then, if I have time, I also go to 100+ IRE Zebra to see which parts are at risk of blowing out. This is a little tricky, because the camera shows everything above 100 IRE under zebra stripes, and we might freak out. But let’s not forget there’s a stop or more of latitude between 100 IRE and 109 IRE, which is the maximum the A7s is capable of in S-Log2 mode.

Q. Is it a good idea to tweak the S-Log2 profile?

A. I don’t think so. Sony has given us a very small window with S-Log2 (which is not similar to the S-Log2 on the F5/F55) and S-Gamut (the A7s sensor is truly special, and has its own gamut). I believe Sony engineers have come up with a gamma curve that takes best advantage of the sensors abilities.

It would take a large amount of study to find any flaws or improvements, and there would be no point eventually. I use the S-Log2 profile in its default state. Zero tweaking.

Q. How do you expose 3 stops over? The camera meter only goes up to 2 stops!

A. Overexpose until the camera meter reads 2 stops (+2.0). Then turn the ISO or aperture dials to one stop over. E.g., if your ISO is at 3200 and you’re 2 stops over, turn the ISO to 6400, and the meter will start blinking, but it’s 3 stops over now.

If you don’t want to change the ISO, and let’s say it’s at 12800 and you don’t want to increase it, but your aperture is at f/2.8 when the meter is at +2.0. Then open up the aperture to f/2 and it’s 3 stops over now.

Or just use the Zebra, as I’ve explained!

Q. Can we use the “official’ Sony S-Log2 LUT for the A7s?

A. S-Log2/S-Gamut on the A7s is not the same as S-Log2/S-gamut on Sony’s other cameras. Sony states this quite clearly:

http://helpguide.sony.net/ilc/1420/v1/en/contents/TP0000435736.html?search=knee

This means the official S-Log2 LUT must not be used with A7s S-Log2 footage. There is no official LUT for the A7s.

Q. Can you explain how you go about using the wolfcrow system, the actual steps?

A. I’ll break this down into two sections:

What I do before the shot

I always start by locking my f-stop. Interiors, it’s at f/2.8 most of the time, sometimes f/4. The shutter is also locked to 1/50, only to be touched if my career is at stake.

This means, I’m left with the ISO dial. I try to stay between 3200 and 12800. If I have to go about 12800, then I know I have a lighting problem.

When shooting video, my Mode dial is on Movie. I don’t grab stills, as the motion blur really ruins it for me. When outputting 4K, it has to be in Movie mode. If I want to shoot stills, I have that set to my Memory bank, just a turn of the dial and back, and I’m done.

My S-Log2 is at its default setting (PP7). That’s how I like it.

What I do on set

I custom white balance first – it’s not possible in Manual Exposure mode so we have to jump through Sony’s hoops. Here’s how I WB.

One should not auto white balance in S-Log2 mode. I’ve got picture profiles on my Fn button so I dial it off first. Then move to M, take a still of either a white or grey card – there’s no need to zoom in because only the center circle (spot meter circle, because I’m always on spot meter) is read and needs to be within the card. Once that’s saved I go back to Movie mode and choose the preset if not done automatically.

I look at the scene on the LCD and/or Shogun. I turn on the Zebras (it’s also on my Fn for easy access) and set it to 70 as per the wolfcrow system. On the Shogun I turn on the 105 zebras so I don’t have to waste time cycling between them.

If I’m shooting a face, that’s where I’m looking for zebras. Now this is not easy to do when starting out, because a face or object is rarely flatly lit like a chart. That’s where the wolfcrow system video-section about skin tones and 40 IRE come into play. Also, different DPs expose for skin differently. Some like to underexpose. I like to overexpose skin by a stop, and if my lighting ratio is 2:1 (two stops difference) then in my head I go through these calculations:

  • The skin needs to be overexposed by a stop
  • The wolfcrow system places middle grey at 70 IRE, so this means, the skin should be at 76.6 or 80 IRE
  • I turn the Zebra to 80 IRE. Is the lit side plastered with zebras? Then I’m good. Otherwise, I need to either turn my ISO dial or add light.
  • The dark side of the face is two stops lower, so it will be at 50 IRE, which is perfect. If it falls below 40 IRE, I must bounce fill.

My face is exactly where it needs to be.

Now, I look at the 105 IRE on the Shogun (or just dial it on the A7s). This is an anxious moment. If I have windows or clothes blowing out, then I let out a huge sigh. Time to make a decision.

Something must give. What? I turn off the zebras and study the image as-is. Are the highlights blowing out gracefully? Am I getting the mood and feel I want? If yes, then I shoot.

If no (the more likely scenario), then I ask myself:

  • Can I use a graduated ND to bring down those areas (this works a lot of the time)?
  • Can I flag those portions (doesn’t work for windows)?
  • Can I throw light on the face and use an ND over the lens, or gel the windows, or any of the hundreds of things a cinematographer can do?

If no to all of the above, which is what we all find ourselves in shooting run-and-gun stuff, then I must lower my levels. I lower my ISO until the blown out region falls under the 105 IRE zone. If I’m shooting S-Log2, then the ISO won’t go below 3200, so I’ll have to use an ND filter (I won’t touch my aperture, it’s sacrosanct). If there’s no time to grab an ND filter, then I use the shutter.

Either way, now I know by how much I have to reduce the overall exposure. By now the skin might be at 50 IRE or 40 IRE or worse. Either I throw some light on it, or ‘expose normally’ and live with the color noise.

Which is more important? The window or the subject? In my mind the subject is always the most important.

All this hardly takes me a minute, most of the time just a few seconds. Now with the waveform on the Shogun, I really don’t need the 105 IRE setting anymore. I still keep the 70 IRE on the A7s just to have a clearer idea of what I’m doing. I don’t like looking at zebras because it distracts me from the shot, but without an external monitor, there’s no other tool on the A7s that tells you the right exposure.

Also, the LCD on the A7s cannot be trusted for video. An external monitor is better, though if you’re shooting S-Log2 they are also useless where superwhites are concerned. The color space is S-Gamut, and no Rec. 709 monitor can show that. The only tool that will allow you to be sure about highlights is the waveform monitor.

The A7s blows out gracefully, and that’s all that matters to me. Once you conduct a few tests of your own you’ll learn to understand the way it works in the highlights. It will inspire more confidence in the camera’s ability to handle highlights gracefully in S-Log2. That’s how DPs learnt to light film and understand its limits, except we can do it much faster with a monitor and waveform. In fact, it’ll just take a few hours.

As explained in the video, ETTR is murder for color grading due to varying exposure and noise levels, and the histogram should not be used for video. The levels on the histogram don’t correspond to video levels.

The wolfcrow system allows a DP to keep exposure constant (a big deal in cinematography) and noise levels constant (a big deal for grading, VFX, chroma keying, and compression) from shot to shot. It allows a DP to shoot as in the film days, by understanding exposure and being able to dictate it. You can’t light for ETTR without wasting loads of time. You can’t use ETTR when you have specular highlights and superbright regions. If one is always worrying about the highlights one’s subject will be inconsistently exposed.

The wolfcrow system also allows a DIT to create a 3D LUT for a scene that will look consistent on set from shot to shot. This LUT can be used by a colorist across the entire scene in one go as reference. An ETTR setup would require a separate 3D LUT for every shot, as documented by Sony in their S-Log2 whitepaper.

Finally, it allows the colorist to match shots faster with more accuracy in post processing, even using the shot matching feature found on the Avid. In conclusion, the only way to keep a workflow fast with quick turnaround times is to be consistent with exposure and white balance. That’s all the wolfcrow system does –  it asks for exposing at 3+ to keep the noise levels down, while giving you enough latitude to reign in those highlights and still give you all the advantages of ETTR without the post processing hassles.

There are some situations where +3 is unworkable, so a DP can choose to be at +2 or +1 even, as long as that number is consistent from shot to shot. Of course, it introduces color noise, but that’s the limitation of the Sony A7s and its specific S-Log2/S-Gamut system. Every camera has such limitations.

There’s a reason why the Alexa or Epic doesn’t offer ETTR, nor do you see many real cinematographers asking for it, nor is it a big part of ACES; and neither is it recommended by any of the EBU documents on exposure.

Q. Can you explain how to use the wolfcrow system for moonlight or dark night scenes?

A. Are there going to be any highlights (moon, torches, fire, etc.) in the shot? If no, then you can actually go much higher than +3 as long as you don’t clip, and you remain consistent across all shots. This is important so you have the least noise in the shadows.

It is critical to maintain exposure across shots so you can cut them together and grade them easily. This will also help you match noise levels from shot to shot.

First, find the most important thing in the shot. If it’s the actor’s face, then that needs to be at the wolfcrow spot (+3, +3.5, +4 whatever, the higher the better, but it must stay consistent or the noise levels won’t match later).

Then, figure out if you want the background to be entirely visible with sufficient detail. If you’re stopping down, there will be fine detail, if not, there will just be texture. Is this texture important to you? If yes, then this ‘darkest region that is still important to you’ must be above 40 IRE.

Or above +0.5 stops on the spot meter. How do you translate this? As a starting point, real moonlight is about 1 lux, or about f/1.4 at ISO 20,000. That’s pretty dark. To be at +0.5 you’ll need about ISO 32,000 at f/1.4. Assuming shutter is at 1/50. The correct mathematical number is ISO 30,000 but we’re erring on the side of caution.

Your actor should then be lit for +3 or 70 IRE. On a meter the lit side will read f/2.8 to f/3.5, but under f/4.

Next up, turn the zebra to 80, 90, 100 and 105 IRE. Pay attention at 100 and especially at 105. If nothing blows out at those levels you still have a couple of stops of headroom on top, and you could push the wolfcrow system to +4 or even +5 if the scene allows.

So, you ‘lock’ two things:

  • The lower level (above 40 IRE)
  • The skin exposure (+3 or whatever, but it stays locked for all shots)

However, if you have a large expanses of darkness, with little texture. E.g., dark clear skies or snow, where noise will be very apparent, then lock on the 40 IRE point and let the skin vary a bit. It’s okay, it will look natural as the subject turns this way and that. The dark expanse will not distract the viewer from shot to shot when noise levels change. If you lock it to 40 IRE, the noise levels will remain constant from shot to shot. If you don’t have this, but have forests, then it doesn’t matter, and you should lock the face.

If you do this right, you’ll be blessed with two things:

  • When you bring everything down in grading, you’ll have beautiful tonal detail and texture throughout the image. It will look rich.
  • The noise levels will be way low (we’re shooting at ISO 30K so there will be noise, and overexposing allows us to crush noise later), but whatever noise remains will look organic.

Please use my numbers only as a starting point. There could be tons of variations. I can only advise you to not wait till the day of the shoot, and test the scene immediately.

If you have lights in the scene, here’s what I would do (using the spot meter on the A7s or a dedicated light meter):

  • Somewhere outdoors, meter the background (doesn’t matter what it is) and the actors’ skin, and note down the exposures.
  • If you have fire, light it up and meter that. Also meter the ground near the fire.
  • Then, switch on the lights and meter its effect on the background and actors. Note everything down.

Now you have a lighting ratio map of each of these elements in relation to the other. This relation does not change whether you’re shooting film or Rec. 709 or S-Log2.

Then try to figure out if the lights are powerful enough to get the background to your desired level. Don’t just peg it at 40 IRE. It is entirely possible that the ground looks great two stops below the main subject, so it would be at 50 IRE in that case. Don’t start looking at IRE until you’ve understood your lighting ratios first!

Test the lighting fixtures at the distance you plan to have it and you’ll know. E.g., my Yonguo YN900 panel meters at f/18 at ISO 3200 at 10 feet. The further the light, the more even the illumination across the scene and it will look natural, but LEDs are not powerful enough for that kind of distance. If you bring it too close, the fall off will be too rapid, and the scene will look ‘lit’. Try to get this right before shoot day.

Does anything blow out the background when pointed at it? If yes, then tape/scrim it or use a smaller fixture. Even if you have to reduce exposure to keep anything from blowing out, try not to get the background below 30 IRE.

 

Click on the link below to the next lesson or head over to the main menu (above). If you need help with something, feel free to send me an email. I’ll try to get back to you as soon as possible.

How to tweak picture profiles, a walkthrough

Every picture profile has settings that you can tweak to taste. In this lesson we’ll go through each setting.

These settings are buried inside the Picture Profile menu:

MainMenu

The right side is just one menu, scrolled down. Each picture profile can be tweaked to taste, and the camera remembers your choices. On more than one occasion, I’ve played with something and forgot to change it later!

Therefore, once you decide what picture profiles you want (you only have a choice of seven slots from PP1 to PP7), the first thing to do is Reset them:

Reset

From this point on, you can start tweaking settings.

Important: Always tweak picture profiles on a calibrated HDTV Rec. 709 monitor, otherwise you won’t get what you see. If you don’t have access to a monitor, leave everything at its defaults.

Note: Since we’ve covered Gamma and Color space (mode), we’ll skip it.

Black level

The Black level can go from -15 to +15. The default is 0.

BlackLevel

What does it do, really? An example should help. Here’s what Cine 1 (Cinema color space/mode) looks like in its default state:

Blacklevel0

Now here’s Black level at -15:

Blacklevelm15

Finally, here’s Black level at +15:

Blacklevel15

Black level lowers the overall black level, the effect is of crushing or flattening the blacks. -15 lowers it by 15 IRE and +15 raises it by 15 IRE. The main thing is you have no control over how the blacks are crushed or flattened – so you either like the look or you don’t.

Note: Black Level is disabled for S-Log2 and Rec. 709 800%

Black Gamma

Black gamma has two choices, Range and Level:

BlackGamma

This works like the ‘Curves’ feature in color grading applications, and you can tweak which range you want to operate in – except in this case the range is limited to the shadow region, from which you select wide, middle or narrow.

Once you select that, you shift the level. It goes from -7 to +7, with Middle/Level 0 being the default. Here’s how it works. Default view:

Blackgamma0

Here’s +7:

Blackgamma7

Here’s -7:

Blackgammam7

So, rather than shift the black level, the level stays the same, but you’re shifting the gamma only in the shadow region.

Together with Black level and Black gamma, you can completely control the shadow region in your image in-camera. And this is preferable to doing it in post because I believe (I could be wrong!) the processing happens before compression.

Knee

If we can manipulate the shadows we should also be able to manipulate the highlights, right? That’s what Knee does:

Knee

Knee comes in two flavors – Auto and Manual. By default, everything’s in Auto, and unless you’re stuck in a situation you can’t fix, I highly recommend you let this remain as-is. Knee only works in Manual shooting mode.

Under Auto, you can select the Max Point (IRE) where the highlight will clip. The value ranges from 90%-100%, which is within the broadcast range. The scene I shot doesn’t have any clipping highlights, so the following doesn’t show much. Let’s start with Auto, High Sensitivity, 90%:

KneeAutoHigh90

Next, Auto, High Sensitivity, 100%:KneeAutoHigh100

Next, Auto, Mid Sensitivity, 90%:KneeAutoMid90

Next, Auto, Mid Sensitivity, 100%:

KneeAutoMid100

In Manual Mode, you have a greater range for Point, from 75% to 105%. It helps to go to 105% for a little more highlight detail. To go with this, you can also control the Slope (another word for ‘highlight gamma’) from -5 to +5.

This is 75% point, Slope 0:

KneeManual75Slope0

This is 75% point, Slope +5: KneeManual75Slope5

This is 75% point, Slope -5:KneeManual75Slopem5

Too bad my scene doesn’t even go above 75 IRE!

Either way, I recommend you leave Knee in Auto at all times, unless you have a strong and valid reason not to. If Knee is set to Auto at 100%, that’s pretty much as the profiles are designed to be.

Notes: Knee only works in Manual Mode, and there’s a weird quirk:

If you set [Slope] to +5 in [Manual Set], [Knee] is set to [Off].

Saturation

This one’s simple, it changes the saturation. You can go from-32 to +32:

Saturation

Here are the results. First, Saturation at 0:

Saturation0

Saturation at +32:

Saturation32

Saturation at -32:

Saturationm32

The camera doesn’t go all the way, either way. I suggest you leave this setting at its default value, which is 0, unless you have a strong reason to change it.

Color Phase

The Color Phase lets you go from -7 to +7:

ColorDepthPhase

What does it do? Here’s Color Phase at -7:

ColorPhase7

Here’s Color Phase at -7:

ColorPhasem7

Wow, there’s an obvious shift in colors, but not the blacks and whites.

What has changed? The Hue has shifted. The best place to notice this is a Vectorscope:

VectorscopeTweaking

The white and black points stay the same, while the hues pivot (rotate) around. Now think of the potential. If you want to tweak skin tones a bit (11 o’clock is the skin tone line) you can do that to make it look just right.

Of course, you can’t go haywire because it also shifts the other hues as well. For more control, we have the next option.

Color Depth

As shown above. Color depth allows you to change seven colors – R (Red), G (Green), B (Blue), C (Cyan), M (Magenta), and Y (Yellow) individually. You can go from -7 to +7 on each.

R +7

R7

R -7

RM7

G +7

G7

G -7

GM7

B +7

B7

B -7

BM7

C +7

C7

C -7

CM7

M +7

M7

M -7

MM7

Y +7

Y7

Y -7

YM7

According to Sony:

This function is more effective for chromatic colors and less effective for achromatic colors. The color looks deeper as you increase the setting value towards the positive side, and lighter as you decrease the value towards the negative side. This function is effective even if you set [Color Mode] to [Black & White].

This is really powerful stuff. You can tweak the colors (hue) while not touching the ‘levels’. Achromatic means Black, Grey and White. Chromatic is everything else. So, if you shift the hue with Color Phase to get skin tones right, you can use Color Depth to tweak the rest of the colors to taste.

You can also use it for Green Screen or Blue Screen work. However, these need to be tweaked on a case-by-case, scene-by-scene basis. Otherwise they all stay at their defaults.

Detail

Detail changes the perception of sharpness, but doesn’t sharpen directly like an app does. The levels go from -7 to +7:

Detail

Within it, you also have a second complexity level called Adjust, which I won’t touch. However, Sony does try to explain what they are for:

Adjust: The following parameters can be selected manually.Mode: Selects auto/manual setting. (Auto (automatic optimization) / Manual (The details are set manually.))
V/H Balance: Sets the vertical (V) and horizontal (H) balance of DETAIL. (-2 (off to the vertical (V) side) to +2 (off to the horizontal (H) side))
B/W Balance: Selects the balance of the lower DETAIL (B) and the upper DETAIL (W). (Type1 (off to the lower DETAIL (B) side) to Type5 (off to the upper DETAIL (W) side))
Limit: Sets the limit level of [Detail]. (0 (Low limit level: likely to be limited) to 7 (High limit level: unlikely to be limited))
Crispning: Sets the crispening level. (0 (shallow crispening level) to 7 (deep crispening level))
Hi-Light Detail: Sets the [Detail] level in the high intensity areas. (0 to 4)

The only setting I change is Detail. By default, Detail is -7 in S-Log2, while in others it’s 0. I always use -7. It delivers the most pleasing image, and I can always sharpen in post if I want to.

I highly recommend -7 across the board.

Copy

The last thing is Copy. Once you save a particular setting, you can copy it to another profile so you don’t have to do everything from scratch:

Copy

That’s it!

FAQs

These are important topics raised by subscribers that shed more light on this lesson.

Q. Can you mix and match color spaces. I’ve heard this xxxx use Pro space with the Cine profile.

A. Okay, this answer is going to be a bit long-winded, but please bear with me.

First of all, I want you to know that I have actually written an image processing algorithm (a rudimentary version of Photoshop, if you will) back when I was in college (2000). So, I understand the math and science behind this way more than the average blogger or user.

Knowing what I know, you need to follow Sony’s instructions on matching color spaces with their respective gammas. They are designed to go together, and if you change it (I don’t care what other bloggers or users say) you are asking for unpredictable results. It might look good in certain conditions, but it won’t hold in all conditions. All other picture profile settings are irrelevant if you neglect this basic marriage that Sony engineers have designed.

The ‘sweet-spot window’ for all profiles is very small (that’s how they have designed the camera so it won’t compete with the F5 or F55).

I know shooters with high-end broadcast cameras who get their footage rejected because they neglected to study their footage using the proper tools. Trust me when I say, it is in your best interest to shoot with the default settings and grade in post – especially with the A7s.

Q. If you were to tweak the picture profiles, how far would you push the settings? E.g., would you push saturation to +32?

A. I wouldn’t push the settings too far. Unless you have a broadcast monitor and scopes with you, it would be hard to know what you’re doing.

Secondly, broadcast monitors don’t display images in the Cinema, Hypergamma or S-Gamut color spaces.

Here are some notes:

  • I would not change the Knee.
  • I would also not increase the saturation beyond 3 or 4.
  • I would not change the Color Phase or Depth at all without the use of a true broadcast monitor in the field.

Q. Which is the best picture profile?

A. There is no picture profile setting that works well in all scenarios…unless it’s S-Log2 in its default settings.

Click on the link below to the next lesson or head over to the main menu (above). If you need help with something, feel free to send me an email. I’ll try to get back to you as soon as possible.

How I use Cine1 (Case Study: Thrissur Pooram 2015)

Here’s a quick run-through of Thrissur Pooram, a unique festival that takes place every summer in Thrissur, Kerala – my home town:

Here are some important notes:

Everything was shot in 2160p25 in Prores LT. Audio is from camera. I did record audio separately for some events but it wouldn’t have been consistent in the final mix.

I’ve only used the gear listed in this guide, and nothing else.

The exhibition

This was shot in S-Log2 using the wolfcrow system and graded using the new Lumetri color panel in Premiere Pro 2015. I am so used to shooting everything in S-Log2 I forgot this project was a case study for Cine1.

The morning ritual

A few of the shots have an ugly color tinge to them, caused by cheap filters that I forgot to take off. I did notice it eventually on the monitor and took them off. Unfortunately, I had to grade the good footage somewhat to find a suitable matching point. I’m not sure I succeeded.

This was shot in Cine1, AWB at about 10-11am in the morning.

Drums symphony

I love how the skin tones look for Indian skin in Cine1, which is why I prefer it. As you can see from the blown out highlights (crowd in the sun), it doesn’t have the dynamic range of S-Log2.

The only way I could have improved it somewhat is by custom white balancing the scene. This was AWB, shot in the afternoon. Entirely ungraded.

Kodamattam – war with umbrellas

Shot in Cine1, AWB. The A7s has no trouble catching the most natural look (to my eyes). This was shot in the late afternoon and went on a bit after sunset. The A7s can actually eliminate the dark and through some creative exposure I could have made it all look like the same time!

This is something only the A7s can achieve.

The Shogun didn’t have any problems with display in these extremely hot and sunny conditions. The light was changing very fast and such a sequence is difficult to grade. This sequence is entirely ungraded.

Fireworks

This was shot on a mobile phone in 2012. And it is scarier and louder than it looks.

If you are interested in learning more about Thrissur Pooram, here’s an article I wrote about it.

The making, and shooting an event with the Sony A7s

Thrissur Pooram happens over a 24-hour period, during the hottest part of the year. Still, crowds in the hundreds of thousands, including hundreds of foreigners, arrive from all corners of the globe to attend this unique event.

Most of the channels and agencies covering the event had multiple broadcast cameras. The biggest agency had 16 cameras covering the entire event. There are many rituals in different locations across town that all culminate in the umbrella war, and then the fireworks war. Me arriving with one camera was like bringing just a fork to eat steak.

We can’t do much about the lighting, as it’s bright and ugly for most of the day. In the evening, things get really interesting. I had a media pass so I could access any location – but as is usually the case, there are fights for the best spot. Many camp for hours, chain tripods or light stands, and generally resort to any tactic to get their spot. There were also two Red Epics and an Alexa on location – filmmakers who wanted to record the action for some reason.

I was assisted by my assistant Pranjal and my cousin, Abhijeet, who recorded audio separately (none of which I used). Pranjal took the BTS stills and video on my 550D.

Here’s what it felt like (very short BTS):

Download Video

A few notes on each event:

The morning ritual

We arrived late, and got a high vantage point but was right behind a tree. A lot of the footage was unusable because I would be doing a slow pan or tilt and somebody would bump my camera. That’s why broadcast cameramen use heavy duty tripods, because bumps are inevitable when cameramen are cramped together.

Drums symphony

We arrived two hours early to get this spot. I was sacrificing prime real estate for the next event for this one, because I’d never seen it before. By the time this ended, there was no way we could make it up to the media scaffolding (which you can see in the video). I did send Abhijeet to find a spot early, but he couldn’t get in – it’s cut throat, and you have to be prepared to posture.Drum1

Of course, ultimately, no one really fights – or they risk not getting the shot – and not getting paid the peanuts they are getting paid anyway. Being a broadcast camera person in India is depressing and thankless.

There were some shots where I had to pan left and right, and this was almost impossible because there were cameras on both sides. You couldn’t even free your arms. There was one funny moment when a large photographer (6′ 4″) walked among us looking for a spot, calling out “low profile” (small footprint, because he had a gitzo tripod). Even camera persons have form factors! I am definitely not the right body type for this job.

Drum2

Kodamattam – war with umbrellas

This is an unforgiving event to cover if you don’t have multiple cameras at high vantage points. I was forced to take a spot near the temple, which was dangerous. At the end of the event, when people started moving quickly, we had a small stampede, and I was almost thrown off the side (a big drop under the VIP section), gear and all. I was protected by one policeman and Pranjal, who certainly saved my equipment from catastrophe.

Ground2Still, it was that or nothing. I was standing on a slope, and people kept bumping into me throughout the shoot.

One of the downsides of covering the Pooram is you can’t go out to get something to eat or drink, so you have to carry supplies. We did carry many bottles of water, but had nothing to eat until late at night when we returned home. I also injured my toe standing at an awkward angle the whole time, but that’s part of the job description.

We also had some interesting media news this year, with Pamela Anderson writing to the Chief Minister of Kerala asking him to replace all the elephants with paper elephants.

Ground1Lots of people in awe of the A7s camera! Pranjal was eternally vigilant, making sure my stuff was not stolen.

The event ended well after sunset and we had to walk for more than an hour with all our gear. They don’t allow vehicles within the periphery of the Pooram for fear of a terrorist attack. You can see they had deployed almost every policeman in the district for this festival – which is probably the most important one in Kerala.

Fireworks

Because I had injured my toe, the prospect of walking another 5km just to get to our spot, and then wait for a couple of hours till the fireworks show started at about 2-3am, I decided I didn’t want to cover it. It would sure have looked spectacular with the 14mm.

It is scarier than it looks in the video. By the end you are not sure if something terrible has happened or if you’re alive or not.

If you ever have the inclination to visit Kerala in April or May, then visit Thrissur during the Pooram (Pooram means festival) because this as unique an event as any. I don’t know if they’ll still use real elephants five years from now, or if the fireworks will be so crazy then.

My thoughts on using the A7s as an event camera

Many people complained when I stated in my review the camera is not a good choice for event work. To my friends who asked me to recommend a camera for event work, I told them to get the GH4, and they are all happy.

The A7s is a prima donna. It needs caring, a careful eye on focus, good filters and an understanding of color science. The broadcast cameras around me had just one setting, and they’re off.

Not so with the A7s! You could try to rig it to make it work, but you’ll always be pining for the things that matter most – servo zoom, lock-on focus, depth of field, lack of rolling shutter skew, ergonomics, long record times, etc.

On the other hand, I’ve found it also offers some important features: a big monitor, excellent imagery, shallow DOF and the ability to rack focus, mind-blowing low-light performance and the ability to mount any lens you please.

Still, I wouldn’t recommend the A7s to a professional for event-based work. Time and expectations of the customer take precedence over ultimate image quality. If your customer doesn’t care, and is only paying for your time, then as a business person all you need to do is satisfy your customer in the fastest way possible. That’s why you need broadcast cameras even today – an Amira would have helped, but it too lacks many of the ergonomic benefits of a broadcast camera.

You can also see how it is impossible to demand perfect colors by shooting Cine1, or by tweaking Cine profiles in-camera without a broadcast monitor in controlled lighting conditions (read studio).

Keep things simple, and you will be happy.

Skin tone test – Comparison of the Close Up

In this lesson we’ll compare the correctly exposed close up shots shown earlier. I’m not displaying which profile is which, because that would bias the results somewhat. Pick your favorite, then read on to find out which is which, and which one I prefer.

Important Notes:

  • The exposure varies wildly because lighting conditions were changing, and my assistant was holding up a white reflector, but not always at the same angle.
  • I don’t remember using an ND filter for any of these shots.
  • The white balance will be thrown off because her face is in shade, and is being affected by green grass. A custom white balance would have worked better.
  • A carefully controlled lighting test would have been better, so this is not an entirely accurate or fair comparison. Don’t make any serious judgements with this, and it is preferable to conduct your own tests.

Click to enlarge:

ComparisonofCloseUp

Which ones do you like? Write them down first and make a decision.

Images in order: Standard, Neutral, Movie, Cine1, Cine2, Cine3, Cine4, Rec. 709

Which ones I like and why

I can tell you the most accurate in terms of skin tone is Movie and Rec.709, with the latter slightly thrown off due to a green cast or changing lighting conditions.

None of the cine profiles reproduce skin color accurately, but that’s not why they are there. They give a certain ‘look’ to the image, along with good dynamic range, and it is up to you to decide which you prefer.

As I mentioned in the last lesson, I prefer the neutral look of Cine1. Here’s a comparison of all exposures made with Cine1 (click to enlarge):

ComparisonofCine1

If you can get past the bluish cast due to incorrect white balance, you’ll see how Cine1 can hold skin tones from plus 2 stops over to minus 2 stops under, but nowhere as near as S-Log2, which can actually do plus or minus 4 stops.

In the next lesson, I’ll outline a project I shot entirely in Cine1, and then reveal my settings for it. But for heaven’s sake don’t copy it. Conduct your own tests – that will be more fruitful I assure you!

Skin tone test – Comparison of the Long Shot

In this lesson we’ll compare the correctly exposed long shots shown earlier. I’m not displaying which profile is which, because that would bias the results somewhat. Pick your favorite, then read on to find out which is which, and which one I prefer.

Click to enlarge:

ComparisonofLongShot

Which ones do you like? Write them down first and make a decision.

Images in order: Standard, Neutral, Movie, Cine1, Cine2, Cine3, Cine4, Rec. 709

Which ones I like and why

The simplest and most pleasing colors would possibly be the default Movie picture profile, though at the expense of dynamic range and highlight clipping.

Cine4 seems to be good too, but also loses out on highlight clipping to Cine1. Cine1 is slightly more ‘washed out’, but it gives the best dynamic range. Cine2 is very close to Cine1, but like I’ve explained in an earlier lesson, Cine2 is for low light situations where Cine1 won’t work.

My pick? Cine1, because it offers the most neutral colors and the most dynamic range just in default mode. This is the picture profile I use when I’m too lazy to shoot S-Log2.

But let’s see how the profiles fare in the close ups.

Skin tone test – Rec. 709 Picture Profile

In this lesson we’ll see how the Standard Creative Style works for skin tones.

Notes:

  • First, we’ll look at the long shot, and then the close up.
  • Each scene is underexposed by 4 stops and 2 stops, overexposed by 2 stops and 4 stops and correctly exposed.
  • White balance is Daylight, constant.
  • All footage recorded in XAVC S in camera, in 1080p25.
  • Click images to enlarge for 100% view.
  • Model is wearing makeup in the close up, but not the long shot.
  • In some cases a 4×4 ND filter was used, and this might introduce color shifts. I was shooting at high-noon, and this was unavoidable. The best way to overcome this bias is to study all the exposure details.
  • I’m bouncing light off a white reflector in the close up.
  • Credits: Model: Riya Chanda Assistant: Pranjal Vedant

Long shot comparison

5Lm4Rec709 4Lm2Rec709 3LRec709 2Lp2Rec709 1Lp4Rec709

Close up comparison

5Cp4Rec709 4Cp2Rec709 3CRec709 2Cm2Rec709 1Cm4Rec709

Skin tone test – Cine4 Picture Profile

In this lesson we’ll see how the Standard Creative Style works for skin tones.

Notes:

  • First, we’ll look at the long shot, and then the close up.
  • Each scene is underexposed by 4 stops and 2 stops, overexposed by 2 stops and 4 stops and correctly exposed.
  • White balance is Daylight, constant.
  • All footage recorded in XAVC S in camera, in 1080p25.
  • Click images to enlarge for 100% view.
  • Model is wearing makeup in the close up, but not the long shot.
  • In some cases a 4×4 ND filter was used, and this might introduce color shifts. I was shooting at high-noon, and this was unavoidable. The best way to overcome this bias is to study all the exposure details.
  • I’m bouncing light off a white reflector in the close up.
  • Credits: Model: Riya Chanda Assistant: Pranjal Vedant

Long shot comparison

5Lm4Cine4 4Lm2Cine4 3LCine4 2Lp2Cine4 1Lp4Cine4

Close up comparison

4Cm4Cine4 4Cm2Cine4 3CCine4 2Cp2Cine4 1Cp4Cine4

Skin tone test – Cine3 Picture Profile

In this lesson we’ll see how the Standard Creative Style works for skin tones.

Notes:

  • First, we’ll look at the long shot, and then the close up.
  • Each scene is underexposed by 4 stops and 2 stops, overexposed by 2 stops and 4 stops and correctly exposed.
  • White balance is Daylight, constant.
  • All footage recorded in XAVC S in camera, in 1080p25.
  • Click images to enlarge for 100% view.
  • Model is wearing makeup in the close up, but not the long shot.
  • In some cases a 4×4 ND filter was used, and this might introduce color shifts. I was shooting at high-noon, and this was unavoidable. The best way to overcome this bias is to study all the exposure details.
  • I’m bouncing light off a white reflector in the close up.
  • Credits: Model: Riya Chanda Assistant: Pranjal Vedant

Long shot comparison

5Lp4Cine3 4Lp2Cine3 3LCine3 2Lm2Cine3 1Lm4Cine3

Close up comparison

5Cm4Cine3 4Cm2Cine3 3CCine3 2Cp2Cine3 1Cp4Cine3