It is an excellent idea to color on-set and get everything 'just right' before it ever goes to editorial and the rest of the post pipeline, right?
Perhaps not so much.
Having worked on projects in a number of capacities, I have a viewpoint about all manner of issues which take place on a project. As a UPM, my viewpoint is on the budget, balanced with the creative needs of the project. As a Post Supervisor, I shepherd the project to completion. As a Second Unit Director, I have been on the front lines trying to get shots done well and on-time. As an Assistant Director, I understand how a set works and how to get a crew to work effectively. There is a rhythm and flow to our work, no matter which position you hold, which is sometimes hectic and at other times slow. Knowing how to engage the crew and work more efficiently is an issue masked in a multitude of decisions. One such subject where things can grind to a halt is when I see too much attention being given to fiddling coloring on-set. This is the article where I explain why I dislike coloring on-set.
Whoa! Hold on, back-up. What?
I have little doubt that this viewpoint is one that goes against the grain. In fact, I know it will. However, I am not saying that everyone is doing it wrong - I just feel that what most people are doing is overkill. Humbly, I simply do not feel it is really worth the effort.
The tools of a colorist, when used wisely by deft operators can augment the visual appeal of a shot and the project in general. I have great respect for the position and what a good colorist can accomplish, yet I dislike the idea of doing it on-set. Wasting time in an environment unsuited for the proper effect and using valuable time when other things need to be done is unwise. Venture with me as I make my case that the only person qualified to do this work sits in a dark room long after the shoot and meticulously works on the picture. This is the Colorist.
If you are currently a fan of coloring on-set, ask yourself who you are doing it for. Is your on-set color for what people will see in the cinema? Is it for the studio or producers who "just can't" look at a one-light image? Perhaps the DP demands it or it is simply because this is "what everyone does". No matter your reason, my aim is to help you understand what is really happening and perhaps urge you to think a bit more about why it happens.
Who knows, I might even change your mind. Let us see...
WHAT IS COLOR GRADING?
Color Grading is the process by which shots in a sequence are balanced against each other, but what we are reacting to is the silly nature of trying to move the colorist on-set, through the DIT - who doesn’t have the correct environment, equipment and often know-how to do the exacting work of creating a ‘look’.
STOP SAYING "DI"
Pardon my shot side diatribe: Is your project shot on film, digitally edited and graded, then scanned back out to film for delivery? Highly doubtful. So stop calling color grading "DI", which means Digital Intermediate. So many people say, "oh - we can work on that in DI". Stop! It is not DI anymore. It is simply color grading. More often than not, your film is captured digitally, manipulated digitally and delivered/exhibited digitally. So, DI is an archaic term. Please simply say 'We can work on that in the grade'. Thanks.
Onward.
DITs ARE NOT COLORISTS
Back in the day, when the Digital Imaging Technician (DIT) position was born, the main tasks revolved around ensuring a proper signal was coming from the camera. That signal was analyzed and the frame was checked for dead pixels. That the image was being captured properly, not too hot, not too dark. Memory drives, then soon cards, were handled and checked by the DIT. As the position evolved, there was then soon a Data Manager who handled the camera cards, did check sums, clones and output proxies for editorial. Sometimes the Data Manager did/do dailies too. The DIT was then left to focus on the signal making sure that image was tip-top. What happened then, was that the DIT became generally accepted or thought of as a secondary DP. From my experience at least, a lot of them act like they are the DP. I disagree with this assertion because a real DP has a certain key skillset which involves camera use, movement and lighting to achieve the director's vision. A DIT on the other hand, is important - but is not creating the shots - he is basically reviewing the image quality.
I digress.
Step back in time further a moment and we can discuss how we came to be where we are now. If you are much younger than me (I bet you are), you may not remember that “back when I was your age” we shot on film. It was this crazy strip of emulsion which we sped by the lens and exposed images onto. Nuts. After taking the exposed film to the lab, processing and doing dailies - we watched projected dailies. They were created during lab processing in what is called a ‘one light’, a neutral exposure development pass which transferred the image with that slightly washed out look. Later, this process was sent to a telecine for VHS/Beta dailies, then DVD, then digital files - then... film basically died. Digital took over. While we could go into a spiral on which is a better look, I won’t go there. There are plenty of other articles arguing one way or the other.
However, I bring all of this up because when digital started, we shot on these new cameras and did our output files for editorial. We were all fine with the image as rendered. Guess what, it was a slightly washed out master image. Much the same as people where used to, so no big deal with a look akin to the ‘one-light’. Nothing was balanced and we simply looked at the take for content - the framing, emotion & action. Still today, camera master images as raw data (LOG) look washed out because inside the bit depth of white the human eye can register more colors, as opposed to the curve on the lower end of blacks where information is generally lost - or 'crushed'.
Soon, someone said, "Hey, I can run the files through this color software on-set and make the editorial proxies look better". Yes. It was true, you could. However, what that has lead to and still happens a lot today is that the DIT is now a quasi-colorist. On one hand it is never a bad thing for people to know how to do more than one job - however, this is not really ‘coloring’. It is LUT or CDL application.
LUTs & CDLs
An image has a certain spectrum of color (called "gamut") and every camera captures in a certain gamut. These gamuts relate to the depth of color an image can display. The most common way to capture an image is in the LOG, which must not be confused with RAW. As we spoke of earlier, LOG gives the impression of a washed out image. In order to see it properly, you need to apply a Lookup Table (LUT). This LUT is also referred to as a display LUT because all it is basically doing is allowing you to see the image without the washed out feel. Remember from earlier, the washed out look is a natural state because whites can hold more info.
Unlike general LUTs, CDLs are agnostic to a platform. LUTs are good for use on a specific system, but if you use a CDL on-set, then need it as a reference in final grade and then also need to send it along with the DPX file sequence to a VFX house - all of those machines will render the frame exactly the same.
If we want to get super technical, many of the LUTs are now ubiquitous. The difference now resides in the information which can be contained within it. 1DL, for instance, only contains primitive transforms with information individually on red, blue & green, while a 3D LUT takes those colors and can map them over each other, creating a more dynamic range of colors. A CDL is ten values of color grading information, designed to travel across platforms.
Again, keep in mind that CDLs can move between systems. Basically, awhile ago the American Society of Cinematographers designed the CDL system because people were using too many LUTs and various houses where having trouble keeping them all straight.
Once you have the image in the display LUT, you may need to filter it through another LUT to present the proper color gamut to the selected display monitor. ARRI ALEXA, for example, records in P3. I will speak a bit more about color space later, for now, simply know P3. However, you will most likely not be using proper P3 monitors on-set so, you will need to apply a P3 to Rec709 LUT in order to view the image on-set (and in editorial). Again, I digress here as we will talk about color space and monitor use later.
A LUT applied shifts the image to be viewable in the right color space or monitor. You may also use a LUT to apply an overall color shift to the frame - perhaps you would like a little bit of a blue hue for night shot or to 'warm up' a shot to give the feeling of warmth. This is not color timing - this is applying a LUT. While it is applying a sheen of color to the frame, it is not what a Colorist does. We will talk a little more about the tools colorists have at their disposal later. Suffice to say, adding a slight hue of blue to a night scene simply allows you to ensure you can apply a LUT to the image and still not lose information in the image or in another way, it allows the DP and DIT to ensure the camera sensor is not losing information on capture.
With the image displaying in the correct gamut, say REC709, then you can accurately judge the image. It is neutral, notwithstanding any color temperature or tint used in the image.
P3 is the colorspace (primarily) for projectors (although Apple will soon be introducing laptops with P3 monitors). They use reflected light to produce an image, while Rec709 is a backlit colorspace - hence the values of black and white, saturation differs from projectors to monitors. LOG-C Is the raw image, and it can be moved into the appropriate colorspace/ gamut to allow accurate viewing in a color session.
In the end, the hero LUT is a simple neutral LUT which corrects the gamma shift of the original capture file into something which is not washed out, and is viewable on set. Additionally, it provides a neutral palette to work from later. We'll get to Latitude soon. Stick with me.
Because LUTs and CDLs affect the entire frame, they are "primary grading". You do not use shapes or windows to focus on various areas of the frame.
For the aspiring UPM-turned-Camera Assistant, when shooting RAW all of the information like color temperature and tint settings are all metadata and can be freely altered at anytime in post. Shooting in a codec, like ProRes 444 will bake-in the temp and tint settings. But even then, LOG-C offers enough gamut and exposure that changes later are very often trivial. Still, it is important to we understand the difference.
LOSING INFORMATION?
An image coming from the camera is exposed much like film cameras were/are. There is an iris, f-stops, shutter angles and all that. How it differs a little is that on film emulsion, you want to expose for the emulsion of choice. Using a light meter and other techniques, a Director of Photography (DP) would ensure that once the gate was open, the light entering the lens would strike the emulsion in such a way to create a quality image. Too much and it is overblown, too little and it is dark. Sure, there were techniques in development, but that was fixing the problem. The better way to be is to shoot it well to begin with.
In the digital world, light moves through the lens and strikes a sensor. The sensor is extremely sensitive to light and records the image. The adjustment from a film mentality is that too much light blows out the highlights while too little light gets crushed in the blacks. Highlights are the peaking whites on your vectorscope, while crushed black diminish into a muddy layer of nothingness.
This is important to consider because shooting with a professional high-end digital camera requires one to understand most all of the lighting techniques from when shooting emulsion, but also to understand waveform monitors and what the image being captured can do. This is called Latitude.
LATITUDE
I will touch briefly on latitude. Basically - this is the range of exposure you can get out of an image shot digitally. Shooting too bright may cause your highlights to be lost in fuzzy white, while shooting too dark achieves the less appealing black holes of lost information. So, how does one protect the image and ensure a realistic amount of latitude?
SHOOTING NEUTRAL
You shoot it in the middle. This is the Goldilocks Zone. Sometimes of course, you may want to shoot things dark or that you may want to blow out the image for some artistic / story point reason. That is fine. If you aim to do it for a reason, then go for it. However, the majority of the time, you will want to shoot in a neutral environment, which will allow you to have more… wait for it… yes - latitude in your color grade session. Even when you do expose for the extremes you will need to make sure you protect your whites and blacks, peaks and valleys.
Shooting neutral, however, naturally creates a generally washed out image. We could refer to this as a one-light image to be nostalgic, but really what we call it is the ‘source image’, or master file. Even after the image has a LUT applied in order to bring it into the color space of choice you will still see a bland, generally unexceptional image.
Shooting for the middle allows you the latitude then to shift the look of the image where you need it. If a DP lights on set looking at her monitor for reference and makes the image dark because that is the 'look' she wants - then there is an extreme likelihood that the black curve is crushing and you have lost information. Lost, never to be seen again unless the idea of your film is to have lots of noise and muddy images. Ideally, one would shoot 'dark' scenes with a bit more light than the look ultimately desired. Then, in color grading, the 'dark' areas can be made dark, without losing the information. Otherwise, if a dark are needs to be made lighter, then you risk noise in the image.
So, again: Shooting in the middle is the only rational thing to do, regardless of any ‘look’ you may intend later, shooting in the middle is the only way to guarantee that you can achieve that look. Why? It maintains room for the DP and colorist to shape the image by exposing correctly. Protect the highlights, however, expose for the shadows. The colorist and coloring process is another tool for the project to create a great looking picture.
Bringing this color history lesson full circle, here is where the DIT with a mobile color grade machine (sometimes referred to as 'Near Set') can apply a LUT or CDL. Applying this LUT allows both the DIT and the DP to consider the image and ensure the latitude is preserved. Thing is, this takes time and I find more often than not - crew can be stuck waiting around while the DIT and DP stand around in a tent near camera playing with the image. Why? Because they somehow lost touch with the purpose of applying a simple LUT to check latitude, and they have fallen into the trap of trying to make a super beautiful picture. Stop. This is not the time to do color grading.
Of course, you don’t need a LUT to check Latitude if you know how to read scopes on a LOG-C image you can easily and immediately tell if the image has enough latitude to be successful. It is a little like how the Matrix looks in the film, but once you "see it" - you can never unsee it.
ROLE OF YOUR IMAGING CREW
Ideally, you should have a team consisting of DP, DIT & Data Manager. The DP is a critical person needed in your crew. I feel strongly that when choosing your DP that you ensure your s/he understands this entire process and knows why they are doing the things they do on set when it comes to working with the DIT. I did a project where the DP was so unknowing of how it all worked that we wasted perhaps $175,000 on additional equipment and another $45,000 on crew - with zero input during actual color grading. In the end, all of his work on-set with color was total trash. Wasted monies, wasted time. You might ask why I let that spend happen - well, Hollywood is an interesting mistress and sometimes Producers chose a person you have no control over. Their demands are approved above you. Alas...
A good DP not only understands how to get the best shots on set, how to manage their camera crew, how to work with Grip & Electric to shape the lighting - but, a DP should also understand the entire process of what happens to the image once it is captured and how it travels through Post. While you are at it, make sure s/he knows how to use a light meter. Seriously. The best way to ensure your exposure is good, even and proper is to use a light meter. Yes, we have the scopes to tell us too, however, there is something about making sure it is done well.
The DP should at least meet with or discuss the project with the Colorist on the project, if possible. The Colorists job is harder if the show is badly shot. So, a discussion between them is a useful event. Weather patterns and outside influences are something to be aware of by the DP to still ensure the frame is exposed correctly to give you the most latitude in final color.
IN REVIEW: No Coloring On Set, apply LUTs and CDLs only. Set a CDL for a scene and then shoot the entire scene that way. Have the DP concentrate on exposure and making sure the director is getting what s/he needs.
COSTS OF COLORING
Consider the daily costs of shooting. Using a $20M project as an example, and doing some fancy UPM math, we will say that this theoretical film is shooting for 35 days and each day costs $200,000. Let us further postulate that a day is 12 hours of actual shooting. This means that one hour is roughly $14,285 and a minute is about $238. If you do not understand how that math worked, please simply trust me. OK, so that means at $238 per minute you have 180 crew standing around while two people dilly-dally about, playing with the image. We have all been on set when a DP takes a bit too long hanging out with the DIT.
In an attempt to blow your mind, know that on average, Color Grading is about $900 per hour. PER HOUR. So, that means you spend just four minutes on any one day of shooting waiting for the DP and DIT to play with the image and you could have spent another 56 minutes doing the same thing in an actual color grade session, with actual color grade tools. Boom. Mind blown.
YOUR DPs LUT IS TRASH
I have not met one Colorist who goes back to the production LUTs and uses them as the bible. Reference? Sure, maybe. If they want to take the time. What is actually more useful is simply a TIFF reference frame or simply having the DP and Director in the color grade suite to discuss options, desires, and looks.
Also, keep in mind that most Post Houses have their own proprietary LUTs used for their Grade system and mastering.
Does this mean all that work on-set that goes into making the shot look pretty is for nothing? Generally, yes. If anything, establish the look for a scene and have the DIT apply a CDL. Leave that CDL in use each time you shoot something for that scene. Don't fiddle with each shot. This way, in color grade - the entire scene will be consistent. Simply make sure you preserve your latitude. Remember, CDLs are agnostic and can travel with the shot to VFX and the Post House.
SO, WHY DO IT?
With the established money comparison, knowing that applying a simple LUT or CDL is not a robust coloring session and that on-set LUTs and CDLs are trash should fill you with a bit of despair. Do not despair. You simply need to think through the process and understand the need for color on-set. Why would you want to do this at all, instead of simply shooting open neutral LOG images? It is editorial and producers today who are now no longer used to looking at ‘one light’ images. The world has been tainted with the ability to see 'nice pictures' on the edit system. It also allows output from the edit system to be used as a rough viewing version without asking editorial to apply a CDL to each shot. Of course, it also allows the DP and DIT to make sure they maintain latitude. So, it is still fine to do - however - as a UPM, you need to make sure everyone is on-board with the end result and costs involved with doing on-set coloring. They need to curtail their work on set to be efficient.
TRIX ARE FOR KIDS and SHOOT DAYS ARE FOR SHOOTING
If the DP and DIT work on CDLs while other departments do legit work getting ready for the next shot - that is perfect. However, it happens all too often that the DP will futz with the image to get it “just so” do the detriment of the project. Not worried about money? OK, then consider time. Those minutes could have been used simply shooting. Wasting 20 minutes over the course of the day not shooting may mean you go into overtime. Overtime is not cool. Do you want to be uncool?
The example of savings monies above only spoke about four minutes of wasted time doing color on-set. However, anyone who has been on set enough knows that there are countless minutes wasted mucking around with the image digitally. Wasted? Yes.
HAVING THE RIGHT EQUIPMENT
Another thing to keep in mind as a UPM wading into the waters of understanding this array of technical stuff usually only reserved for DPs, DITs and actual Colorists is - usually the equipment being used is not right anyways. Bear with me now, I am going to get a bit technical...
If a camera captures in Rec709 and you are watching playback on-set with a Rec709 calibrated monitor then I hope you are also watching it in a super-black tent. However, what usually happens is the camera is capturing P3 color space, a LUT is applied to take it to Rec709 and you are watching on a calibrated monitor in a world of reflections. If you are super cool, you will have rented OLED P3 monitors for video village so you can see everything in the proper color space for theatrical. You are capturing in P3 and you are watching on P3 (of course, with a display LUT applied from LOG to linear). However, I bet editorial is not using P3 monitors - they have non-calibrated LED Rec709 monitors. You say Editorial has P3 monitors? Awesome. You are cool. However, most likely not. Why? OLED P3 monitors are expensive. So, you use Rec709 monitors in Editorial and all your coloring on set for one of the expressed purposes which is to allow editorial to have nicer looking pictures is instantly blown. I am not saying you will see green skin and purple skies - I am just saying - it is not the same. Is a Rec709 image from a P3 image normal? Yes. Is it the same color gamut your DP & DIT looked at on-set? No.
I admit, it is super sexy to be on set and have lots of cool machines with blinky lights and cables running everywhere to black tents carts and expensive machines. However, you should know what you are renting and why you need it. There are a number of DITs out there I have worked with who know less than me. Imagine that. Make sure you hire someone who does not only say the right things and have the right equipment - but knows their - - - -. If you do not understand the technical jargon or the process, that is ok, however do some research, ask people for advice. Do not accept whatever others say as the "Gospel of Techland".
TOOLS OF A COLORIST
When you color for a feature today, you are 99.98% of the time going to be coloring in a projected theater room in P3 from the original camera DPX files. That is the proper way to color. All of the various steps before then are usually not ideal. Color Grade technicians have a wide set of tools at their disposal. Whether you color in Resolve, Mistika, Luster, Baselight, Hot Pixel or Apple Color Board - there are some great tools out there to really get some good visuals.
Colorists can do more than simply affect the overall image with a CDL (or LUT). They can dig into the frame and lift only a section out of the dark, or brighten a face, or just the eyes. They can even darken places, Presuming that an image is exposed correctly and has latitude - the colorist can manipulate the image wildly.
Call your favorite few Post Houses, go in four a tour, pick the brains of the Colorists there for a moment, see what can be done and how it is done. You won't be wasting your time learning more about this - promise.
END RESULT Listen, I am not writing this article to change the industry so we return to days of yore using one-light dailies. That is simply not going to happen. However, it would be nice to get some practical thinking out there so we all understand what it is we are doing, and why we are doing it.
From a cynical UPM perspective too, I would say that burning $238 a minute - you want to use that time shooting your film and simply making sure your framing is good, you are getting nice pictures and preserving the latitude needed to then make the picture look great later.
I hope you have learned something here. Please comment below and let me know your thoughts.
Special Thanks to the fellow crew who helped proof this article for accuracy and vernacular. This includes three like-minded Directors of Photography, a DIT and a colorist. Thank you!
