A remarkably complete and accurate kit for implementing a bias or back lighting setup.

MediaLight Bias Light

Highlights

MediaLight 6500K Bias Lighting System

  • High CRI LED Light Strip
  • USB or wall powered
  • Full featured dimmer and handheld remote included
  • Very affordable price

MEDIALIGHT LIGHTING SYSTEM REVIEW SPECIFICATIONS
Length of Light Strip:

140cm/55in (Standard kit) or Two 61cm/24in (for Wall Mount Kit)

Correlated Color temperature:

6500K

Colour rendering index:

90

Included components:

AC Power Supply, Dimmer, Handheld Remote, Cable Clips

Cost:

$49.95

Company:

BiasLighting

SECRETS Tags:

MediaLight, 6500K, Bias Lighting System, Lighting System Reviews 2016

Introduction

So you’ve done your research, been all over scholarly journals like ours, spent countless hours on forums, shopped to the point of exhaustion, and now you’ve just bought the perfect new HDTV. A world of video nirvana awaits you…or does it?

Your hypothetically stellar performance new TV, if placed in this room…

MediaLight Bias Light
Image courtesy of Vizio

… is going to look like crap.

I feel your pain: You wish you could have just thrown money at the most expensive TV in the world, plopped it on the wall, and be done. Sadly, it doesn’t work like that… at all. Incidentally, it doesn’t work for audio either: the above fictitious living room will make the best loudspeakers in the world sound like someone is talking through a paper cup. But I’m getting off topic.

Consumer media and hardware, especially HDR, is built around very specific luminance standards. You cannot simply “turn up brightness” to watch a movie in a sun-lit room. Well, you can in that the video gestapo wont break down your door. After all, there is a distinction between “casual” viewing of the evening news and “critical viewing” of your favorite director’s latest release. The point here is that a display, even an excellent one, placed in room bathed in sunlight (or other overtly bright lighting) will be washed out and have a fraction of the dynamic range it could have, if only it were calibrated correctly and enjoyed in the right environment.

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The way our eye-brain works, in concert with our video standards (both legacy and HDR), we simply must put that beautiful new HDTV in the right environment in order to get the most out of it. What makes for the right environment is actually pretty simple, not subject to much debate at all, yet it is so rarely addressed in quasi-home theaters the world over. Specifically:

  1. The room must feature total control over ambient lighting. This does not mean a pitch black room (well it does for very large projection systems but lets not get sidetracked by that right now). When we say controlled ambient light, we mean exactly that: that we chose how much light is present, what type of light, and the specific areas that light illuminates.
  2. The portion of the room which falls within our field of vision must be color-neutral.

These two points work together in concert to create the ideal viewing environment.

The Color of Color

The wall behind the screen, and anything on it or in the field of view of the person watching the movie, needs to be absolutely neutral. No reds. No blues. No vintage movies posters. While I’d like to say that goes for the entire room, I concede you can get away with deviations on the side and back walls but the wall your HDTV is against has to be neutral grey.

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Seeing is believing so I encourage you to pause here and take two minutes to look at the excellent color perception demonstrations found on echalk.co.uk.

While these may seem like contrived, forced examples, the fact is that the color of the wall surrounding a movie on a TV screen does affect our perception of color in that movie.

Maybe you don’t care. “After all”, you may be thinking “my movies don’t look bad right now even though I have Andy Warhol art plastered all around my screen”. That you are here reading this suggests you care about having high fidelity images though, and you simply cannot achieve that unless you go beyond buying good hardware. I appreciate this is a tough one to sell significant others on. As such it may be a gateway conversation to you building that dedicated home theater you’ve been dreaming about for a while now. After all, if you can’t sell them on a neutral wall, how will you ever get the ceiling painted black, which incidentally is really the ideal for a home theater or media room. Best thing I ever did, after installing acoustical treatments, is go with a black ceiling in my theater. But I digress.

As Joe Kane is fond of saying: neutral does not have to be boring. Patterns are ok, as are a variety of textures and materials, as long as the colors are all neutral. A light grey wall accented with dark grey acoustical panels for example can look classy and complimentary in terms of decor. For those interested in perusing this you will either need to take a grey card (available at most good photography stores) or one of CinemaQuest’s Munsell Neutral Values chart.

to your local paint store and have them color match it (simply asking for “grey” will almost certainly get you something which is anything but).

So let’s say you have a nice neutral toned wall behind your TV. Illuminating it properly is even more critical.

Ambient light and the need for bias lighting

Any room in which your intention is to realize accurate, high fidelity video must be carefully crafted in terms of ambient lighting. This means, by definition, either no windows or windows with coverings which do a considerable amount of light blocking. In practical terms it does not have to be extreme blackout curtains, but the point here is that “daylight” is not part of an ambient light controlled room.

The first cardinal rule is that no light shall directly illuminate the face of the screen. If that’s the case where can we have some light?

General Lighting

For one, you can have low localized ambient light almost anywhere in the room. Dimmed diffuse sconces for example can give off enough light such that you wont trip moving around the room and, perhaps more importantly, so that you can see the bowl of popcorn and your soda (or smelly cheese platter and glass of fine Amarone….as case may be). Dimmed is the key word here. In my micro-theater I use a handful of track lights with PAR50 style bulbs which have a very focused beam pointed to the side and back walls: I can see my lap in front of me, have a sense of where the walls are, but that’s about it in terms of “general” lighting. Another option is recessed pot lights with focused bulbs, again very much dimmed. None of these ambient light sources should reach the front of the room though.

Bias Lighting

The other light you can have, nay, in fact need, is bias lighting, also called display backlighting.

A bias light is a light source placed directly behind the display itself, essentially illuminating the wall behind it. That is, from the viewer’s point of view, the wall surrounding the picture they are watching. There are two very specific and sound scientific reasons why we want to do this.

  • Eyestrain/fatigue. In a pitch black, or near pitch black room, even the 100 nit luminance peak of SDR (standard dynamic range) is enough to be an issue for your eyes. As you watch a dark scene your eyes open up. Then a bright outdoor scene comes on the screen and your eyes have to clamp down, fast. Then a dark scene. Then a bright one. Its akin to watching a two-hour movie while doing curls with a dumbbell: your eye muscles are going to cry out. For this reason, we want just enough light in the room to “bias” our eyes, to keep our pupils from opening too much such that when the bright scenes come along its not such a violent change for our eyes.
  • Perceived contrast. A sort of beneficial by-product of a bias light is that in preventing our eyes from opening up too much, the absolute darkest darks on the display appear just a little bit darker. This actually improves the subjective dynamic range of the image you see. In a pitch black room most displays reveal their inability to do pure black (the complete absence of light): with a pure black test pattern you actually see it as a fait glow. Add just a bit of bias light, your pupil closes just a bit, and that faint glow appears more black.

There are two immediate questions which come out of this: what kind of light to use, and exactly how much? Too little light and the exercise is pointless. Too much is almost worse in that your eye is overly biased and now you cannot see into the shadow detail of the picture.

The light source itself has to absolutely be the correct color temperature with a sufficiently high color rendering index, otherwise you will just be tinting that neutral wall we talked about, ruining the effort put into it. What we want is a light source which is a strait 6500K, matching the white point of consumer video display calibration.

How much light is a little harder to peg. Going back a couple decades to the advent of consumer awareness of standards, Joe Kane and his A Video Standard LaserDisc put the maximum amount of bias light at 10% of peak white. That is, subjectively, the bias light should appear no brighter than the bias light level test pattern he provided. In terms of objective quantification, the recommended practice guidelines from various standards organizations vary a bit. One issue with measuring light is the discrepancy between luminance (measure on the face of a display) and illuminance (the sum of light arriving at your face).

Then there is HDR.

As we will explain, somewhat vehemently, in a forthcoming primer, HDR is not about raising the mean brightness of movies. It is about extending the dynamic range such that the lion’s share of the image will still be within the SDR range while highlights extend into the extreme luminance values. What this means is that, contrary to current misconception, HDR does not necessarily require a dramatically brighter bias light. Actually, in some rooms it may be the contrary: with HDR display technologies pushing the black boundary of the image into virtually true black, it is very easy to have too much bias light and miss out on those silky blacks we’ve been lusting after since the retirement of CRT. In fact, in ITU-R BT.2100-0 (Image parameter values for high dynamic range television for use in production and international programme exchange) the reference environment is defined as having a background brightness of 5 nits, and more specifically a surround brightness (the area immediately around the display) of <= 5 nits. That’s less than or equal to 5 nits, and what is more, that recommendation is predicated on an HDR display hitting 1000 nits!

The bottom line is that rather than getting hung up on a specific luminance (or illuminance) metric for a bias light, it is sufficient to say that it will probably need to be dimmer than you think. In my opinion if you have the tools to measure light, 5 nits measured in the plane of the display is a great place to start, but don’t be afraid to experiment a bit from there. In the absence of measurements, a very useful starting point is the tried and true bias light brightness pattern (from something like the S&M Benchmark blu-rays) and “by eye” ensure that the bias light is subjectively no brighter. For the more technically inclined you will also want to view a variety of PLUGE patterns to make sure the bias light is not so bright as to cause blacks to appear crushed. The key is that whatever is used for a bias light has to be adjustable. Not only is the light output needed situational, it will also be influenced by the shades and textures of the room: a very dark grey wall, or one with dark cloth covered acoustical treatments, is going to call for a stronger bias light than a flat wall painted a light shade of grey.

So we need a light source which is a solid D6500, conveniently fits behind a display device, and can be adjusted easily to address different environments and situations. It would also be nice if it didn’t cost an arm, a leg, and a spleen.

For many years the golden standard for this has been the Ideal-Lume line of products by CinemaQuest Inc. Based on fluorescent lighting, it is excellent, but not inexpensive and somewhat difficult to adjust: attenuation is achievable only through the use of an adjustable baffle.

After all, we retired fluorescent bulbs in LCD TVs. The age of LED is well under way.

Enter The MediaLight kit from Scenic Labs.

The Kits

MediaLight Bias Light - The Kit

The MediaLight kits are based on fairly typical looking LED light “strips” designed to be adhered across the back of an LCD or OLED display (or computer monitor for that matter). In truth they are not the first product of this ilk, but I assure you there is nothing typical about them. Let start with the LEDs themselves:

MediaLight Bias Light - LEDs

Jason Rosenfeld of ScenicLabs saw that the LED strips on the market being sold as bias lights, by and large, were anything but a true 6500K. So he combed the industry and found an SMD which is up to standard. He buys them and has the strips assembled to spec in Guangzhou. When I say to spec I mean using a black strip specifically (where white is more common) and no silicone coating. Using a coating is quite common in competing products but is most certainly not a neutral density filter and serves only to alter the color of the LED light (about the only good thing you can say about silicone coated strips is that they are “waterproof” … but who leaves their HDTV out in the rain?). As with most strips, the MediaLight is easily cut down in length if necessary (just follow the easy instructions showing where to snip with a pair of scissors).

The accuracy of the LED strip is only the beginning. Jason aptly identified several other shortcomings of what was being offered as LED bias lights and put together truly holistic “kits”.

In addition to the LED strip itself, you get a USB-A Male plug with a hard on/off switch to power the lights. Since 99% of HDTVs today include at least one USB port, the lights can conveniently be powered by the TV itself. But wait, there’s more.

MediaLight Bias Light - AC-USB power supply

If your TV does not have a USB port, or it is not available, Jason includes a simple AC-USB power supply. And this is not some DealXtreme piece of crap: its is UL and cUL listed. Further, it was chosen specifically for its shape: unlike many wall warts it does not block outlets above or below it. But wait, there is more.

Included is a remote control dimmer! This is probably the most exciting and valued part of the kit. Jason really thought this one through: it is RF and thus the receiver can be positioned behind the display, completely out of sight. It is a high frequency PWM dimmer, operating at 200Hz and thus produces no visible flicker. But the biggest ace up its sleeve is that it remembers its previous state when power is cut to it! This is obviously a critical feature since, ideally, the power source (be it a USB port or the AC adapter plugged into a switched outlet on an AVR) will cycle as part of your whole system on-off. Of course if that’s not the case the handheld remote can also be used to turn the unit on and off or you can use the hard switch. Either way, it still remembers the previous dimming state. Buttons on the remote are included to take you strait to levels of 10, 20, 40, 60, 80 and 100%. There are also +/- buttons to fine tune it further (a total of 45 stops). But wait…that’s right, there is more.

Also included in the kit are some very handy plastic clips with self adhesive to help tidy all this up on the back of your TV, support the weight of excess cable, etc. The LED strip itself is backed with a peel-and-stick 3M adhesive.

The various components (light strips, power plug/switch, and dimmer) attached to each other using a common barreled DC plug. So if you don’t want to use the dimmer, you can eliminate it from the bundle at the back of your TV.

All in all, a remarkably complete outfit.

The MediaLight comes in two flavors: one with a single long LED strip suitable for most applications, the other includes a pair of shorter ones, intended to be a solution for LCD/OLEDs mounted directly on a wall: since there is little to no space behind the screen, instead of running a single strip horizontally across the back, the two LED strips are applied vertically down back edges of the display. This kit has all the same accessories plus a “Y” cable to drive the two light strips.

Evaluation

While Jason and his company have an excellent reputation, I wanted to independently substantiate his claims for you. Using Calman Professional and C6-HDR I set about measuring his lights.

To accomplish this, we placed an X-Rite grey card at the bottom of a black fabric lined box, aimed the MediaLight strip at it, and measured the ambient light reflected off the card. This makes a perfect test of what will be realized in actual use. The result: a nearly perfect 6500K! My results were so good, +/- about 12K, that Jason asked me to point out that’s better than what he promises (which is still a very respectable +/- 150K).

It is important to note that the spectral distribution of LEDs like this will not be confused with true daylight. If I were to aim the C6-HDR directly at the LEDs (which I did) I get wonky results, in particular a blue spike. You’d need a filtered halogen bulb to pass such a test. As evidenced by the grey card measurements though, which in this context is what really matters, these LEDs are as close to perfect as one could ask for.

As a quick sidebar, I tried the MediaLight on the back of my PC monitor which is located in a room without a neutral grey background. When I measure the ambient light in there, it comes out very cool, well over 7000K (the walls are painted light blue). While starting with a 6500K light is better than one which is off, certainly better than nothing at all, if you want to “go all the way” you really have to address the color of that wall.

The MediaLight worked perfectly for us in the 007 Theater and the dimmer works exactly as advertised. I ended up diming it to the 60% level. In my environment that produced a measured luminance in the plane of the display of between 1.5 and 3.0 nits depending on whether the measurement was taken at the side or top of the display. Ramped up to 100% I would get just under 5nits. Given this is in part reflecting off of light absorbing Auralex acoustical foam (grey… naturally), I deem there is plenty of output available and any installation will benefit greatly from the dimmer. If I had a bare wall covered with Mussell N5 or higher for example, I might have needed to dim it even further.

Its worth noting that because the remote is RF it is somewhat contentious to implement multiple bias lights in close proximity (for example in a studio with multiple workstations) as they will all respond when one person uses their remote.

The peel-and-stick adhesive is just about perfect in that it is sufficient to hold the strip in place, particularly if the included clips are used to support the excess wire, yet if you have to remove it, it will come off with little fuss. On one of my displays, a Vizio, the plastic back is very “textured” and the adhesive did not get enough to cling to so I had to use a few pieces of black tape (which will never, ever be seen by anyone but me).

[Note from the manufacturer: For situation like this, customers may request that VHB (Very High Bond) tape be added to their kit(s) when they order. Starting next year some will be included by default. It comes with a warning though: it is so strong that subsequent removal of the strip will likely damage it as well as mare the surface so it should only be used if the installation is truly to be “permanent”.]

Although this falls into the DIY category, one idea some MediaLight users have implemented is attaching the LED strip to a suitable piece of aluminum channel, thus creating a piece which can moved around or mounted apart from the TV itself. An anecdotal side benefit it acts as a heat sink. I asked Jason about providing something like this as an option but admittedly the prospect of shipping an up to 140cm metal channel, not to mention the logistics of stocking or cutting custom lengths would be a nightmare so this idea is better left to the tinkerers out there.

Conclusions

THE MEDIALIGHT will be the Best Cost-to-benefit Cash you Have Ever Spent on your LCD or Oled Based Home Theater.

Likes
  • Very affordable.
  • Excellent specs.
  • Complete outfit, nothing else to buy.
Would Like To See
  • Nothing noted.

Come on: its fifty lousy bucks. MediaLight will be the best cost-to-benefit cash you have ever spent on your LCD or OLED based home theater.

Seriously. Order now.