What is a video production monitor? It is a display used to monitor (study, look at, observe) video, under the following conditions:
- It represents the video accurately
- It is portable
- It is rugged, and can be used in reasonable external weather along with your camera during production
- It can easily interface with your camera
- It provides some link to the final display the video will be viewed on
- It can run on DC or battery power
- It offers ergonomic controls that are easy to operate without a remote
Unlike a computer display, the key differentiating factor for an external display is its portability and ‘affinity’ to the camera. By affinity, I mean it must be able to read the camera signal accurately.
This guide will help you choose an external video production monitor. It’s not that hard, if you know what you’re looking for. Let’s begin.
What are you monitoring anyway?
Monitoring can mean two things:
- Monitoring for aesthetics
- Monitoring for technical validity or merit
To judge aesthetics, one looks at the image, namely the colors, the framing, the focus, and hopefully the performance.
To judge technical merits, one looks at data from the image, reinterpreted as waveforms, graphics or other information. This information is critical to keeping the video within the boundaries of the agreed-upon standard for delivery. Simply put, it is the technical correctness of a monitor that will allow you to enjoy the aesthetics. If you’re not sure about the accuracy of a monitor, you’ll always be nervous about the imagery.
As a rule of thumb, follow this principle: A good production monitor should be capable of both.
How do you judge a shoe at a shoe store? You pick what excites you. Then you might want to see if it fits you, and whether its material, stitching, etc., will work with your lifestyle.
Monitoring video doesn’t work that way. You are primarily concerned with the emotional aspect of what you’re seeing. However, you don’t commit emotionally until you’re certain you are being shown the ‘truth’. A bad monitor can make something look worse or better than it really is, and you don’t want to wait until post production to find out.
The simplest (and only) way out is to understand your camera, monitor and signal. There is no other way to be sure. I am going to assume you know your camera and its color science. What remains is the signal and monitor. Let’s start with the former.
Avoiding mixed signals
If you don’t know what a signal is, start here.
Luckily for most of us, camera manufacturers try to make it simple by processing data within the camera. These ‘processed’ signals are then written to various media. Sometimes, a manufacturer provides a signal, usually uncompressed, via different ports. These signals are not thrown out haphazardly, but are arranged in a very specific way, in the same sense letters are arranged according to the rules of grammar and spelling.
The three most common family of standards that you’ll find on many cameras are:
- Component Y’CbCr (Digital)
The standards are precisely defined, and are critically important indicators of compatibility between external recorders, monitors and other devices, and the video feed out of the camera. It’s supposed to make things easy, right?
Wrong. Even within the standards, you have different versions, and then there’s the problem of differently shaped connectors. The following table tries to provide a brief overview of these standards:
To know about speeds, data rates and limits of data transmission, click here.
You might be forgiven for thinking: If a camera has a specific standard, say SMPTE 292M (HD-SDI), and an external recorder has the same standard in its specifications, then they’ll be compatible, right?
Sorry to disappoint again. Manufacturers are notorious for providing incomplete or vague information in their specifications. Don’t believe me? Download the manuals and try sorting through the technical specifications. If the specifications aren’t written explicitly as I’ve written them in the table above, then the manufacturer is hiding something.
Rule of thumb: Just because a signal is in a specific standard doesn’t mean you’ll get the best out of it. These standards are just packaging, nothing more. More often than not, it hides the dirty sampling and inefficient digital voodoo within the cameras themselves. Even the best monitor cannot make up for this lunacy.
Just as an example, think of egg crates. An 8-bit video feed has 8 slots, and a 12-bit feed has room for 12 slots. You can have 8 great eggs in an 8-bit crate, and 12 rotten eggs in a 12-bit crate. To know more, I strongly recommend you read Driving Miss Digital, so you are no longer prey to all this BS.
An SDI connection (BNC connector) ensures there are no unwanted disruptions by having a locking mechanism (HDMI does not). It is also designed for long cable runs, like about 100 meters (328 feet), for HD. HDMI can only go up to 30 meters (about 100 feet) without an extender. With a good extender, it can equal SDI. But imagine how many HDMI connections does that make? The more the HDMI connectors, the greater the chances of one being dislodged. HDMI (as well as Displayport and Thunderbolt) is designed as a consumer standard, great for when things don’t move around. But that’s not what a video production monitor is about, is it?
Rule of thumb: Choose SDI over HDMI whenever possible. It is designed for rough professional use. To know more about the differences, click here.
Things to look out for with signals
If you’re an Arri Alexa user, you’ll be asking: How is it that the Alexa can output 3K out of dual HD-SDI? Well, they don’t use the SMPTE standard. They treat the two ports as just cabling, and have their own circuitry and protocol, called T-link.
Always check to see if the manufacturer refers to a particular SMPTE standard explicitly. If they do, then you can be pretty sure they are following it (one hopes).
Secondly, watch out for the type of scanning: Is it progressive, interlaced or psF? This is the most common reason for signal mismatch and weird effects. As a rule of thumb, try to monitor in the scan type that the final video will be watched in. If it’s a movie or Ultra HD content, stick to progressive. If it’s going for standard definition broadcast, then monitor in interlaced mode. All this assumes that the camera is capable of giving you a choice. Most of the time, you only have one or two options.
Finally, ask friends or peers. Write to the manufacturer asking for specific information. If they don’t answer, or if the answer only makes it worse, then avoid that manufacturer.
With today’s technology, getting the camera-monitor connection right is as easy as plugging in a display to your computer. If it isn’t that way, somebody’s doing something wrong.
How to find the right size monitor
Start by reading this: How to Find the Right Cinema or TV Viewing Distance.
What is the ideal size of an external monitor? 5″, 7″, 9″, 15″, 24″ or more? Some productions are able to afford more than one monitor, so everyone’s happy. Most productions though, can’t afford or don’t need more than one. If you’re looking for a quick answer, use this calculator:
- The maximum size I find practical on a rig is 14″. And even that’s pushing it. With 4K, you start at 19″, and even that’s only because you want to reduce size.
- The bigger the monitor, the further away you have to go. That defeats the purpose of a video production. 4K is great in this regard, but with smaller monitors you lose the resolution advantage.
- When more than one person is viewing a monitor, they won’t always be at the same distance from it.
- The tendency of most individuals is to always approach the monitor to be as close as possible, just like moths. Yet, you need to keep the shoulder-to-shoulder distance in mind.
- Even though director/client egos might demand the biggest screen possible, the resolution will not support it at close distances for 1080p and lower. For 4K, it’s the other way around; for dailies you need a minimum of 105″ (unless you’re the only one watching).
With this system, I’m no longer bogged down by display size. And now, you needn’t be, either.
What controls do you need on a production monitor?
The sky’s the limit:
- Internal Calibration (Hardware and Software)
- Color Space/LUTs/Profiles
- Color Gamut
- Bit Depth
With RAW files, you might have two additional steps before the signal is ready: De-comprsession (Redcode, compressed CinemaDNG) and De-bayering. This ‘ready’ signal will have to be passed through a LUT for correct display.
Theoretically, a monitor can be designed with rigid standards baked in. Won’t that make things simpler, you might be wondering. Of course not. What looks like good color to one might look like too much to another. What might appear sharp to one will appear fuzzy to another. So whose eye will the monitor be designed for?
Things like bit depth and gamut are not really controllable. These are limitations in technology. Then there are the limitations of standards. E.g., Rec. 709 mandates a certain color space and gamma, and that’s that. One of the most popular mistakes people make is assuming two monitors or cameras with Rec. 709 will display the same color. Nope. It’s not meant to work that way. A color space standard is like a box, and once you’re within the box, you can pretty much do anything you like. Hopefully, with Rec. 2020, there might come a time when color management is simpler (but they have been saying this for decades).
The importance of ergonomics of controls (dials, buttons, etc.) cannot be overstated. You don’t want to be running around looking for the remote or thumbing through infinite layers of menus to find something. If it’s important, it must be a knob or button right where it’ll take less than two seconds to change.
For now, all I can advise is this: Get your monitor to look somewhat like the final display it will be viewed on. E.g., if your audience is going to watch on LCD or LED monitors, don’t judge on OLED or Plasma. The same applies for color grading as well. You’ll only end up disappointed.
Here’s what I do personally: The eyes don’t lie. When in doubt between data and vision, always rely on your eyes. Unless, your audience is an army of data wranglers or signal processing engineers.
Don’t agree? Ask any DP who has shot on film prior to the digital revolution.
How did they judge exposure?
How come they were so certain about colors?
How did they realize their vision on celluloid?
Did they use calibrated monitors on set, with 10-bit displays and LUTs?
Why is it that with all this technology on set many DPs still can’t make great images consistently?
If you know your camera, lighting and lens inside out, you don’t need an external monitor. I find its presence more therapeutic than essential. Seeing an image in its final form on a monitor is a relief to those who can’t envision it in their head.
On the flip side, there are many scenarios where you just walk in blind into a set, or rent gear that you don’t have experience with, or are using a camera for the first time, etc. In such situations the video production monitor comes into its own.
What about technical analysis?
There is no place on set for a technically inaccurate monitor. By definition, a video production monitor is there to monitor video, and it must be capable of it without a shadow of a doubt.
Technical accuracy is directly dependent on the monitor’s ability to analyze the incoming video signal. This analysis must then be presented to you in a form you can understand quickly. You punch a button, find out something and then take action if necessary. Anything slower is unacceptable.
The traditional forms of data presentation (sometimes loosely called ‘scopes’) are:
- Waveform – Displays voltage over time, and the ‘shape’ of the signal – commonly used to study luminance.
- Vectorscope – Displays the relationship between two separate signals in X-Y form – commonly used to study chrominance.
- Histogram – A graph showing the distribution of discrete data (for digital systems) over a defined range – commonly used to study luminance of each channel (RGB) separately, or the overall luminance of the signal.
- Zebra/Exposure – When turned on, the zebra stripes are seen over areas that are overexposed beyond an established threshold. On professional systems, this threshold can be selected by the user.
- Focus Peaking – The edges of an object in focus take on a specific color (professional cameras allow you to choose between a few options).
- Test/Control Signal – This is a standard signal with known characteristics that can be used to check for problems. Even if a monitor has this, I recommend getting a good signal generator with different kinds of signals for a more ‘impartial’ test.
- Color bars, test charts, etc. – Other miscellaneous ways of testing color, resolution, etc.
The key difference between these technical methods and the controls one finds to manipulate the aesthetic image (brightness, contrast, etc) is that these don’t allow for manipulation. They show the signal as is, or at least are supposed to.
Having a professional grade monitor with accurate scopes is like having a truth serum. If you know what you’re doing, it will tell you how ‘good’ your signal really is. If you don’t know what you’re doing, it doesn’t matter what it says!
Monitors specializing in the technical aspects of a image (the final image takes a back seat, and maybe not at all) are also called scopes. To know more, read What is an Oscilloscope and Do you need it for Video?
To recap the previous two sections:
- Controls on a production monitor help you see things better or clearer, while not impeding its technical accuracy.
- Controls should be readily available as tactile buttons or knobs, within easy reach of the operator.
- The tools available on a monitor for technical accuracy (scopes) cannot be manipulated once set, and this gives you the confidence to rely on its imagery.
- It should be a matter of one button push to switch between each scope for fast shot analysis.
Of course, all this begs the question: How do we know the monitor is accurate in the first place? That’s why we have calibration.
I’m not going into details here because it’s a tough subject as it is, and deserves a separate article.
Calibration is the process of testing your monitor against reliable standard tools (See the pattern – a monitor to test a monitor…?). These tools better be reliable, or you’d want another set of tools to monitor them!
These ‘reliable’ tools must be easy to use, portable and cheap. You can’t bring a scientist along, so these must get the job done. To understand why monitors need calibration, check out Eizo’s articles on the subject.
You could calibrate in two ways – software and hardware. Software is for consumers, and should never be used by a video professional. What you need is hardware calibration. This means another thing you need to buy.
For proper hardware calibration, you need four things:
- A monitor that allows it (not as easy as you think)
- A probe (the hardware, the thing that monitors the monitor)
- Software (the thing that makes sense of it all, and controls the monitor)
- A computer for the software to run
The most reliable probe and calibration system that won’t break the bank is the X-Rite i1Display Pro:
Obviously the quality of the probe is important, but the quality of the software and its ‘relationship’ with the monitor is even more so. There can’t be any weakness in the chain. To learn more about calibrating your video monitor, check out Ben Cain’s detailed article on calibrating Rec. 709 monitors.
For free but excellent software, check out Lightspace DPS by Light Illusion.
What to look for in monitors
I realize a lot of what we’ve covered so far is complicated stuff. Color management is complicated, even for the professionals. Most of those who look to buy a production monitor don’t want the hassle of learning (Or even knowing about!) color science, so here’s a list of things you should look for when buying one:
- Resolution – It must be able to take the native resolution and aspect ratio of the signal, even if it doesn’t display it in the same resolution. If the monitor does not display in the native resolution, it must have a 1:1 pixel mapping feature.
- Size – it mustn’t be too small or big, and must be just right for your unique production needs, both ergonomically as well as visually.
- Refresh rate – Should be 120 Hz if possible, or at least 60 Hz.
- It should have frame guides and lines, if possible even custom ones. The standard frame guides are 4:3, 2.39:1, 2:1, 1.66:1, 16:9 and 1.85:1.
- Compatible connector and standard (discussed above, BNC, HDMI, SMPTE, etc.).
- 12 V DC power and battery powered, similar to your camera’s requirements.
- Visible in sunlight, with a minimum luminance of 200 nits (cd/m2). The higher the better.
- Rugged and portable.
- Standard color spaces, especially 100% sRGB and Rec. 709.
- Ability to change Display Gamma to either 2.2 or 2.4; or more.
- Ability to load LUTs and Color profiles, or at least have standard in-built profiles.
- Contrast ratio – Should be as high as possible, the really good monitors can show more than 10 stops or 1000:1.
- Vewing angle – As close to 180o as possible.
- Color depth – 10 bits if possible, but there’s nothing wrong with 8-bits only for viewing purposes.
- Precision – 10-bit processing minimum.
- Analysis tools or scopes like Zebra, focus peaking, histogram, etc.
- Audio levels for all channels supported by the standard.
- Audio playback if possible.
- Weight, Power Consumption and Heat – As low as possible.
- Indubitably ‘better’ than the in-built display of the camera.
- Have ergonomic controls that are easy to use without a remote.
- Have mounting points for easy rigging.
- Upgradeable firmware, with the optional feature of upgrading to accept 4K or UltraHD signals.
Not all monitors will have all of these features. If you want everything, expect to pay more than what you paid for your camera body!
Don’t feel bad. You don’t need the best monitor on earth on a production set. Using scopes will keep your image within the acceptable ball park. That’s what they are for. This is what you should aim for:
- Accurate technical scopes.
- Ball-park images.
- Great ergonomics and brightness.
In Part Two we’ll look at some monitors for each size and format, and some accessories to go with it.