TLCI – a useful measure of colour rendering for LED fixtures
Posted on Monday, November 2nd, 2015
by Andy Ciddor
It’s pretty widely acknowledged that the once-adequate Colour Rendering Index (CRI – published in 1965) that told us about the colour accuracy of fluorescent, arc and metal halide light sources is pretty hopeless as a measure for our modern LED, laser/phosphor and related light sources.
Whilst the CIE (Commission Internationale de l’Eclairage) is grinding its way inexorably to developing an internationally-ratified standard that improves on its old method, the colour experts at the European Broadcasting Union (yes they do stuff in addition to broadcasting the Eurovision Song Contest) set about developing a new measurement.
The new version of their Television Lighting Consistency Index (TLCI) is designed to look at how light sources render images for modern colour television cameras with CCD and CMOS pickup chips, rather than the way things look to human eyes. However as TV cameras tend to be way more sensitive to colour inconsistencies than we are, this metric will give you a pretty good idea how your displays, sets, costumes and makeup are going to look both on camera and to the audience’s eyes.
Like the CRI, TLCI is an index – so a candle, a tungsten fixture and sunlight all come out at 100 for perfect colour rendering, and most other sources come out at something less. The closer to 100 the measurement is, the more accurately the colours of illuminated objects will be seen. The results of the test don’t only produce a number (see the accompanying image), they include a rendering of a standard film colour reference chart as it would appear on camera when illuminated by the source under test, together with a correlated colour temperature (CCT) for the source, a graph comparing the source with either a blackbody radiator or daylight, and some advice for colourists on how much of what type of correction is required to achieve an adequate white balance.
There’s more information about this on the UK Guild of Television Cameramen site at www.gtc.org.uk/tlci-results.aspx and a list of how some luminaires faired in the test at www.gtc.org.uk/tlci-results/tlci-results-new-format.aspx.
Technical details of the TLCI methodology and how such things as the test chips and the camera response curves were developed are available on the EBU web site at tech.ebu.ch/tlci-2012. If you have a decent-quality spectrophotometer you can download a program to assess the TLCI of your own luminaires from this site too.
Tech Topic: The Perfect Programmer Recipe
Posted on Friday, September 4th, 2015
By Brad Schiller
Making the perfect programmer requires a host of carefully selected ingredients mixed together. When this recipe is followed, the result is a highly talented and creative individual capable of orchestrating his/her fingers over a lighting console to direct lighting and video elements into a carefully crafted piece of art. A perfect programmer requires much more than just knowledge of console commands, so it is essential to follow this recipe completely. Mixing the elements together to form a programmer necessitates careful selection of the correct quality ingredients. Let’s take a look at what it takes to make a perfect programmer……
Read the full article at: http://www.plsn.com/current-issue/42-feeding-the-machines/17276-the-perfect-programmer-recipe.html
Tech Topic: It’s Time to GO!
Posted on Thursday, July 30th, 2015
By Brad Schiller
Automated lighting consoles are very complex machines that provide amazing abilities to transition data values utilizing various timing controls. From a simple crossfade between two cues to advanced multi-part timing and auto-follows there are a multitude of timing tools available. Although each console may use slightly different terminology, the abilities are generally the same. For the purpose of simplicity I will refer to one set of terms in this article, so be sure to reference your console’s user manual to determine the exact terms you may encounter.
Read the full article at: http://www.plsn.com/current-issue/42-feeding-the-machines/16936-its-time-to-go.html
Tech Topic: Perfect Patching
Posted on Wednesday, June 24th, 2015
By Brad Schiller
Automated lighting consoles are full of features, many of which rarely get used. However there is one feature that is required for every single show: patching. A patch is a set of instructions that assign specific controls on the desk to fixtures and their attributes in the real world. Without a patch, no communication between the console and devices can take place. It is vital for lighting programmers to understand how to patch their console and how to use the various options within the patch window. While some of the terminology may change from desk to desk, the basic procedures remain the same regardless of the console.
Read the full article at: http://www.plsn.com/current-issue/42-feeding-the-machines/16599-perfect-patching.html
Tech Topic: The Art of Lighting Chrome and Brushed Metal
Posted on Monday, June 1st, 2015
Written by Mike Mahoney
I am blessed to work with some of the greatest scenic designers on the planet. They seem to have endless veins of creativity and come from all sorts of backgrounds and educations. However, it never ceases to amaze me how often they design with the most impractical scenic elements. Well, at least from this lighting designer’s point of view.
One example of this is the design team for Titleist Golf. I have been designing their trade show booths for a decade. I have come to learn that they want a certain look and they will stick with it, come hell or high water. Titleist is the largest manufacturer of golf balls worldwide. As an avid golfer, I jumped at the chance when approached to light their booth.
Read the full article at: http://www.plsn.com/current-issue/35-ld-at-large/16366-the-art-of-lighting-chrome-and-brushed-metal.html
Tech Topic: Lighting Network Basics
Posted on Thursday, April 16th, 2015
Written by: Brad Schiller
Automated lighting programmers are constantly using new equipment and setup configurations. It is very important for programmers to understand how networking has become an integral part of many systems. While a full understanding of computer networking concepts, equipment, and topographies is not required, there are some basic networking principles that you need to be familiar with. The number of lighting devices connected together with wired or wireless networking equipment is growing on a daily basis, but the general purposes can be broken down into three unique situations. However, before exploring these categories, you must understand some basics of networking.
Read the full article at: http://www.plsn.com/current-issue/42-feeding-the-machines/16036-lighting-network-basics.html
Crossfading Industry Scenes
Posted on Friday, March 20th, 2015
Written by: Jess Baker
Whether you’re staring at the same walls deciding if you are going to leave that full time job to go on tour, or sitting in the back lounge of a bus trying to figure out how to “come off the road” and still support your family, making the decision to take that huge leap of faith can leave even the most confident person full of conflict.
In the late 1990s, I was an industry fledgling, working in a lighting shop. Some of the best “road-crew” of that time would prep their tours there. With their ability to load 12 trucks into a venue in a single day and their stories of adventure in exotic lands, I thought they had the coolest job in the world. Going on tour became my first clear career goal. When the higher-ups finally gave in to my nagging and sent me on my first tour, I was barely old enough to drink, had recently finished college, and was ready to see the world.
Read the full article at: http://www.plsn.com/current-issue/35-ld-at-large/15764-crossfading-industry-scenes.html