Inside Track: Picture Perfect, Spears & Munsil
In my capacity as StereoNET’s resident AV reviewer and ISF calibrator, I recently had the chance to speak to Tracey Spears and Don Munsil about their Spears & Munsil UHD HDR Benchmark calibration disc. What follows is a transcript of that conversation…
Thank you for taking the time out of your busy schedule to chat with us about the new Spears & Munsil UHD HDR Benchmark calibration disc. Many are already familiar with yourself and Don and in particular your HD Benchmark discs. For those who are newcomers to home theatre or display calibration, can you share a little bit about your backgrounds and perhaps what inspired you to create the Benchmark calibration discs?
Don: Stacey and I both are big movie fans, and really that’s the core of our interest in home theatre. We both just want to get the best possible presentation of movies and television so we really can experience what the artists intended. When people spend millions of dollars on making a movie, and every single frame of that movie has been massaged and tweaked by hundreds of people, all working at the top of their game. It seems disrespectful to watch it on an uncalibrated TV in “vivid mode” with two-inch speakers!
Stacey: All we want to be able to do is to sit down and watch a movie and feel confident that it looks and sounds as good as it is possible to achieve. We never really have reached what I’d consider the end goal, but we get closer year after year.
Can you share a little about the creative process; so that our readers can get an insight into the work behind creating the disc?
Stacey: A lot of our new pattern ideas come from critical viewing of material. When we’re watching a movie or TV show, we’ll notice unusual artefacts and rather than just shrug and think to ourselves, “must be a glitch” we will often rewind and rewatch it, check it out on multiple displays and try to figure out what is the root cause. If it’s just a compression artefact, so be it, but sometimes it’s not. Sometimes it’s something odd about the display, or the player, or something else, and if we can isolate it that can become a new pattern.
Don: We also get suggestions and feedback from industry professionals who are trying to isolate an artefact that’s been a problem for them, or that they can’t figure out. Sometimes people in the CE industry will suggest a pattern that they hope will highlight a problem with their competitor’s products. They know that other companies are doing the same thing, suggesting patterns that make their competitors TVs look bad.
I know we can all relate to that. The rewinding of a show or movie and wondering what caused it, often to the bemusement of family members. Can you tell us the target audience for the disc?
Stacey: We hope that the disc will have value for everyone who cares about video quality. Obviously, professionals and calibrators will find the disc useful, but you don’t need to be in the industry to use the disc. Anyone who wants to understand home video better and who wants to make better choices about how their equipment is configured will find the disc useful.
Don: In an ideal world we’d have completely different discs for different audiences: one disc for display manufacturers, one for professional calibrators, one for video enthusiasts, etc. Each disc would be laser-focused on the needs of that group. That would be really expensive, mastering all those different discs, so we try to organise the disc in such a way that people can find what they need and ignore the stuff that’s not relevant to them.
While the UHD HDR Benchmark won’t take the place of a professional calibration, can you tell us what home theatre enthusiasts can accomplish by using the disc with their Blu-ray player and TV or projector?
The main value for the home enthusiast is being able to make informed choices about the seemingly endless number of settings we all have in our TV, player and set-top box menus. Every box we own that can produce video seems to have settings for colour space, bit depth, HDMI mode, etc. And every TV has cryptically-named video settings like “deep black” or “true motion”. What do they do? Why would you turn those on or off? We hope that with our disc you can get a better idea of what these various settings do.
Stacey: Are you better off setting your Blu-ray player to output 4:4:4, 4:2:2 or 4:2:0? The answer, amazingly enough, depends on the specific TV you’re using, and possibly the AV receiver as well. If you just kind of eyeball the picture and change the settings back and forth, you are not likely to see the differences without a set of test patterns to isolate specific aspects like sharpness, colour accuracy, chroma resolution and so forth.
Don: In the TV world, you can’t just plug in an HDMI cable and assume that the picture is automatically going to be the best it can be. In theory, the best possible picture format is 4:4:4 RGB, since that’s the native format of the actual physical panel on any TV. In practice, a lot of TVs convert the input signal to 4:2:2 YCbCr or 4:2:0 YCbCr internally for processing, so if you feed in RGB, you’re going to get extra conversions of the picture that you don’t need, which inherently is not going to be good for picture quality. Some TVs can accept 12-bit video but internally convert to 8-bit if you turn on certain processing features. It’s almost impossible to figure these things out without test patterns.
This is something I often encounter, the assumption being ‘more is always better’ and the Blu-ray player should be set to 4:4:4 YCbCr. Can you provide us with a brief overview of the patterns contained in the disc?
Stacey: The disc contains patterns for SDR and HDR to perform everything from a basic video setup by eye, to measuring the gamut of a display with much in between. We tried to group the patterns by subject with the boxes on the left side of the menu. Then within each group, we further try and organise by the use of tabs across the top. I will admit that this is based on our opinion on how things should be grouped but sometimes they do overlap. For the update we have planned for later this year, we have been trying to further refine this. In some cases, this means moving stuff around or renaming all together.
Okay, I’ll bite! Can you share anything about the update planned for later this year?
Stacey: We are working on an updated disc. The plan is to offer an upgrade price for existing customers (original purchaser only). It will include Atmos and DTS:X pink noise for levels, Dolby Vision, SDR 709 and SDR 2020 patterns. It will have some additional patterns added and some existing ones tweaked. We are also cleaning up the montage. One of the new versions will be an HDR Analyser view, which is fun to watch if you are an enthusiast.
What about newcomers to display calibration? Will they be able to understand and use the test patterns on the disc? And for that matter, where can users find instructions on how to use the various patterns?
Stacey: People can find a bunch of free articles on our website that describe how to do basic calibration and setup, plus background information on the various tests that you can do yourself with no test equipment. You can also view articles we wrote for our previous discs, most of which are still relevant to the patterns on the new disc. Of course, there are also more advanced patterns that we have not documented. Some of it is just a reiteration of the previous content but redone in HDR. These patterns are more commonly used by a reviewer, calibrator or CE manufacturer and they have a better understanding of how to use them. More instructions will be coming in the future for advanced patterns and topics…
Don: We think if you can follow basic instructions and can figure out how to get to the settings menu of your TV, you can go through the basic calibration steps. If you’re willing to spend a little time, you can run an evaluation of the various picture modes and settings on your player and TV and learn what modes work best for your specific combination of equipment. In addition, our demonstration video is a great way to see the value and potential of High Dynamic Range video. We really think HDR, done right, is an amazing leap forward in video quality, and our test video really pulls out all the stops and uses as much of the HDR brightness and colour gamut as we can get away with on current video displays.
I wholeheartedly agree. There’s a range of options for users to adjust in SDR. The disc advises against changing a display’s brightness and contrast settings in HDR, as doing so will interfere with the displays tone mapping abilities. Precisely what can users adjust and indeed learn about their display by using UHD HDR Benchmark in HDR mode?
Don: We aren’t actually adamant about not changing most of those settings; it’s just that those settings were designed for analogue TV and with new features like wide gamut colour and HDR tone mapping they’re no longer as relevant. Plus, after years and years of people complaining about them coming out of the factory set wrong, most of the manufacturers are setting them to the correct level, or at least within acceptable tolerances. Colour and Tint are also extremely hard to set on modern TVs unless the TV has a blue-only mode. Modern LCD and OLED TVs have spectral output that doesn’t generally work very well with blue filters.
The exception is brightness. We do actually think it’s worth checking the brightness or black level. But start by checking if there’s a special “black level” setting or if your picture mode is set to “vivid” or “bright” or something before you adjust the Brightness control. Get the TV in the best mode first, then possibly tweak the Brightness control.
Our disc is really best for figuring out which modes and settings you should use on your display and player. You can figure out if it’s better to have your player output 4:2:0 or 4:2:2 (or even 4:4:4 or RGB if the player offers those). If your TV has multiple black level modes, our disc will tell you which is the correct one to use. And you can (and should) adjust sharpness for your specific viewing conditions and distance.
Stacey: I know many people were surprised when we recommended not touching Contrast in HDR mode, but in every case we looked at, changing it did unexpected and typically unfortunate things to the tone mapping. There are always going to be exceptions, but be careful. It’s not like SDR where there’s one correct answer. Until we have 10,000 nit displays in the home, HDR is always going to have the problem of how to map a huge range of light levels into a display that can only show a fraction of them, and that makes it impossible to say how much clipping of the highlights is “correct.”
We can help you see how the TV maps HDR content to the range available on your display, and we can show you what happens when you change the Contrast control, but it‘s the Wild West right now – until there are agreed-upon standards or at least conventions we know are in use in mastering houses, no one can say one TV’s mapping algorithm is “wrong.”
One particularly useful feature is being able to adjust luminance levels (1,000, 4,000 nits, etc.) in HDR to assess the impact on test patterns and reference viewing material. Can you expand on how users can do this and what it can tell them about their display?
Don: The intent there is primarily to set the target luminance to something close to the maximum level your display can produce. At that point, the patterns are effectively optimised for your display. If you want to see how your display reacts to content mastered for brighter or dimmer displays, you can change the target luminance to something lower or higher and see what your display does. “Tone Mapping” is the (usually proprietary) algorithm each TV manufacturer uses to take map very high dynamic range content to the available dynamic range available on the display. Everyone does this task differently since every method has pros and cons. With our disc, you can get a feel for the choices your TV manufacturer has made, and more importantly how changing the various picture modes and HDR modes affect those choices.
Stacey: If you don’t know the peak luminance of your display, we recommend leaving the disc set at the default position of 1,000 cd/m².
What options are available for more advanced users, who own calibration equipment?
Stacey: This disc has more patterns for advanced users and calibrators than any other we know of. It has many of the patterns needed to do a complete pro calibration, including gamut, white balance and EOTF tracking, focus, you name it. If you have access to a good colorimeter or spectroradiometer, our disc will provide everything you need to adjust literally any setting. We also include a lot of content for evaluation. What is the luma and chroma resolution like? Are luma and chroma properly aligned with each other. Is there any obvious lip-sync errors in your setup?
Is there anything you would like to add that we haven’t touched on?
Stacey: We like to get feedback. We know that on this disc that we did not include basic audio setup for object-based audio formats like Dolby Atmos and DTS:X and it also lacks the pop-up help. Beyond these, we are always looking for feedback on what other content people would like to see included. It can be a specific test pattern you are used to or a description of what you are trying to evaluate. I’d also add that we are really at the beginning of HDR. For SDR, the industry has decades of knowledge. We are just over halfway through the first decade of HDR and still have so much to learn. This disc was our first attempt at what we think is needed, but we believe there will be much more to come over the next few years.
Don: Definitely if there are things about this disc you like or don’t like, let us know! We’re accessible and we do listen to suggestions. And check out our website – we constantly add new articles and information about patterns on our discs. There’s a lot of good background as well on video in general.
Thank you again for speaking with us today. I know I speak for many home theatre enthusiasts when I say the wealth of knowledge you bring to the community about display calibration is greatly appreciated.
The Spears & Munsil UHD HDR Benchmark Calibration Disc sells for $59.99 RRP and can be purchased here.
As the owner of Adelaide based ‘Clarity Audio & Video Calibration’, Tony is a certified ISF Calibrator. Tony is an accomplished Audio-Visual reviewer specialising in theatre and visual products.