The Purkinje Effect

the_eye

When I teach beginning lighting design classes, I always have a week of learning about the eye – how your rods and cones balance each other, what their respective jobs are, how the images you see are translated to the brain, and how, as lighting designers, we can use the strengths and weaknesses of the eye to heighten the audience’s experience.  Physiology always comes into play when you’re designing a lighted environment, and students always seem to enjoy finding out what different colors of light do to the body – blues are soothing (even to both genders), reds increase blood pressure and respiration rate, yellows make your eyes tire faster, and black is a submissive color.  None of the really “alternative” students appreciate being told that their black fingernails, eyeliner, and dyed hair color are really signs of compliance.

Inevitably, a question that comes up is “why do we see blue and gray at dusk and when the sun is setting?”  It’s a great question, especially because it lends itself to explanation of the photopic (lots of light, optimal conditions) and scotopic (low light, monochromatic) vision systems, and how rods and cones operate and cooperate.

The Purkinje Effect, as it’s called, is when the sun goes down, and we see a whole lot of blued out and grayed out colors.  This happens primarily at dusk, and in very low light conditions, where the color receptors (cones) basically leave it to the light receptors (rods) for detail for the brain.  When the light goes down, the color information is lacking, so the rods have to compensate.  Our vision becomes monochromatic because our color receptors, which do not interpret intensity information and respond best to yellow-ish light pass the workload on to the light receptors, which respond best to green/blue light and allow us to see shape and contrast.  Just without color.

There’s the lecture for the day.

Test Your Color IQ

Humans can see about – well, millions and millions of colors, according to researchers.  That’s a pretty scientific measurement!

X-Rite has a color IQ test in which you organize hues in order.  I scored perfect, just so I can blow my own horn publicly! Go take the test!  Post your score in the comments.

LDI 2008 – Vegas, October 20-26, 2008

LDI

LDI 2008 is coming up fast – October 20-26, 2008 in Vegas. Have you registered? Who’s going? Unfortunately I’m not going to be able to make it this year, but if you’re a lighting professional, it is THE conference to hit! Count me in for 2009!

Check out the registration, sign up and get yourself to Vegas.  All of the major manufacturers of entertainment lighting products and control are there, and the swag is fantastic!

Wybron’s CXI-IT Color Calculator for the iPhone

CXI-IT by Wybron Color fader users, attention:  Wybron has an iPhone program that is made to correctly calculate the percentages for their CXI-IT color fader – you know, the one with two CMY rolls that mixes 432 “distinct” colors.  It’s also the fader that has the photometric sensor to detect if the lamp’s on, heat sensors, and all the bells and whistles that come with Wybron’s InfoTrace system – the remote device management system Wybron wrote.

Ok, enough of that – this post is about their CXI calculator for the iPhone and iPod.  Wybron’s CXI Calculator gives you the ability to mix the two CMY strongs together and find the specific colors you want to create.  From Wybron’s website:

Mix the perfect color for your CXI IT dual-gelstring color changer with Wybron’s CXI Color Calculator for the iPhone and iPod touch.

Using the Color Calculator’s simple interface, scroll through two overlapping gelstrings of cyan, magenta, and yellow to find the perfect color out of nearly 500 different shades. Then plug its numerical values – either decimals or percentages – into your control console to create the color on stage.

Or find the values necessary to replicate popular GAM, Lee, and Rosco gels.

The Color Calculator replaces the plastic color wheel lighting pros have carried since the CXI came into existence in 1998. But now, with all that information on your iPhone or iPod, you can fit a wealth of knowledge in your pocket.

And the devices’ illuminated screens let you mix and match colors even in the darkest theater.

The Color Calculator runs on any iPhone and iPod touch and can be purchased through Apple’s App Store. Just click on the App Store icon from the main screen of each device, or access the App Store through iTunes.

You can get this program either from the iTunes Store or by clicking the direct link here.

CXI Calc

Friday Morning Productivity Killer: iTunes 8 Visualizer

After installing a 1GB video card to do some amazing WYSIWYG viz, I realized that I still hadn’t figured out how to control the visualizer in iTunes 8 yet.  There isn’t a lot of info posted about the controls for the visualizer (which you reach by pressing CTRL+T, by the way), and I knew there was a way to control the parameters.

Lo and behold – when you press Shift and ? (in order to accurately type a ?) you are given the glorious help menu!  iTubes 8 Viz control is as follows:

? Toggles the help screen
M Changes the mode
P Changes the palette
I Displays the track info
C Toggles auto cycle (which is on by default)
F Toggles freeze mode
N Toggles nebula mode
L Toggles camera lock

Experiment around with these, you can actually get some pretty great video FX for your favorite tunes.  Stand by, because I’ll be writing a review of the Arkaos VJ software soon – that’s like DMX-able visualizations in a box!

Petzl’s Self-Jamming Pulley, The Pro Traxion

Pro Traxion If you’re a stage electrician concerned about safety, you’ve probably more than once used a self-jammer to haul fixtures and cable up into the cats and balconies.  Petzl Climbing Gear‘s Pro Traxion self-jamming pulley is perfect for this task, and is a chosen method for people across the industry.  It’s not cheap – Amazon has it for about $110 USD.  It is completely worth it, however, for your working tool bag.  When you let go of the rope, it jams closed and holds the load until you prove that you can take it again.

Gel Swatch Library for iPhone/iPod

Wybron, Inc (the scroller people) has released the Gel Swatch Library for the iPhone/iPod generation of lighting folk – a program that has the Lee, Rosco, and GAM catalogues, complete with spectral curves and other pertinent information.  From the Wybron product website:

The Gel Swatch Library gives you multiple ways to find the perfect color for your production. Scroll through lists of gels made by each manufacturer, or search for a specific gel name.

Spectral Energy Distribution curves and CMY/RGB percentages listed for each color provide the vital data you need to create breathtaking scenes on stage.

Examine similar shades with the Gel Swatch Library’s side-by-side comparison window, where you can also compare complementary colors to find different shades that go together perfectly.

The library’s easy-to-use interface condenses the swatch books that lighting pros have used for years – putting a wealth of knowledge onto a device that fits in your pocket.

The Gel Swatch Library runs on any iPhone and iPod touch and can be purchased through Apple’s App Store. Just click on the App Store icon from the main screen of each device, or access the App Store through iTunes.

Get a copy of the Gel Swatch Library from Wybron in the iTunes store, or by clicking here.

Studio 1000’s Constellation Lamp

Studio 1000 and Kenzan Tsutakawa-Chinn have produced a beautiful fixture made from a mass of 3mm LEDs attached to strands in a star-explosion like formation.  The lamp is quite beautiful – I don’t think one would do it for me though.  I can see about thirty of these in a large room.

I *highly* recommend checking out the Studio 1000 website.  It’s heavily flash-based, but don’t let that stop you.  Click on the link called “Studio1000riginal” and raise and lower the little dimmer switch.  Amazing stuff.  It’s driven me to figure out how to resin-cast.

original post found on Yanko Design’s website.  Thanks, folks!