The Blue Effect

Blue has a calming effect. The beach scenery with the rich blue ocean is an enticing invite for a relaxing holiday.

Blue colors:

• slow the pulse
• deepen breathing
• lower body temperature
• cause you to relax

East Japan Railway Co. has spent £100,000 fitting out all 29 stations on the capital's central train loop, the Yamanote Line, with the strong bulbs.

The operators believe they will emit a soothing glow, despite the absence of any scientific proof that the method reduces suicides.

Mizuki Takahashi, a therapist involved with the project, said: "We associate the colour with the sky and the sea.

"It has a calming effect on agitated people, or people obsessed with one particular thing, which in this case is committing suicide." Read on.

Berlin - Festival of Lights 2009

For the fifth time, the FESTIVAL OF LIGHTS™ will turn Berlin into a sparkling metropolis with a firework of illuminations and events for two weeks from 14th to 25th October, 2009. World-famous historical landmarks and spots in Berlin, e.g. the Brandenburg Gate, the Television or Radio Tower will be staged impressively by means of light, events, projections and fireworks. Complementary to the festival, there will be numerous cultural events dealing with the subject “light”.

Switch On The Lights

It was the world's first Formula One race under the night sky, and Asia's maiden F1 grand prix on public streets. And now, the SingTel Singapore GP is set to record another milestone on Friday - it will be the first time F1 cars are driven from day into night. While last year's first practice session lasted from 7pm to 8.30pm at the Marina Bay street circuit, this year's is scheduled to start at 6pm and end at 7.30pm.

This is according to the tentative timetable issued by the sport's governing body, the International Automobile Federation (FIA). As dusk will fall shortly after 7pm, championship leader Jenson Button of Brawn and the other 19 drivers will start lapping the circuit in full daylight, stay on as it turns to dusk, and return to the pits for good only when the session ends after nightfall.

More ....

The level of lighting quality increases the well-being of drivers, resulting in traffic safety. Roads must be uniformly lit to ensure safety and driving at 240 mph from full daylight to dusk is a challenge. A big change in illuminance can cause our eyes to shut for a second or two due to our scopotic and photopic vision. This momentarily blindness can be fatal for drivers on high speed.

The next time you travel into and out of a tunnel, check out the lighting. When entering the tunnel, you would probably have extra lighting to balance the illuminance outside and inside the tunnel, and the extra lighting gradually dims as you continue your journery in the tunnel. Before exiting, the lighting is increased to prepare your eyes to the brightness outside the tunnel. This is done to prevent your eyes from shutting momentarily due to sudden change in brightness.

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FORMULA 1™ SingTel Singapore Grand Prix Lighting System
Lighting System
· Horizontal aluminium truss (10m high) supported by vertical steel pylons (32m apart) supported by a footing system with steel plates
· Truss to carry power cables, fibre optic cables, light projectors and DigiColor units
· Centrally controlled by DigiLux System

Light projectors
· Placed 4m apart on the truss
· 2,000 Watt metal Halide lamp
· 4,200 Kelvin degrees

Luminosity
3,000lux levels (four times brighter than the lights at sports stadiums)

Power Supply
12 sets of twin generators
· One generator can produce the energy required for the entire system in the assigned area
· Each generator can take the load of both generators should its twin generator fail

Total power required: 3,180,000 Watts

Total length of aluminium truss: Approx. 6,300m
No. of Steel Pylons: Approx. 230
No. of Light Projectors: Approx. 1,500
Total length of power cables: Approx. 110,000m
Total length of optic cables: Approx. 27,000m
Lighting consultant: Valerio Maioli S.p.A

Whiteness and Yellowness

Whiteness (WI) is a measure of a visual rating of whiteness for white and near-white surfaces. Some common WI are:

• ASTM
• CIE
• Ganz-Griesser
• Hunter

WI is used in textile, plastics and paint industries for near white samples.

Color has three parameters but manufacturers of white colored products find it easier to use a single index scale when qualifying their products. There are many whiteness indices and it is important to note that for a WI to be valid, the correct WI must be used and the materials must be in similar gloss, texture, opacity and other physical properties.

Yellowness Index (YI) is an indication of the degree of deviation from white to yellow. The yellowness of ideal white is almost zero. The more it deviates from the ideal white, the larger the yellowness value.

YI is most commonly used to evaluate color changes in a material caused by wear and tear, degradation through prolonged use or exposure to environment. YI is widely used as an indication of deterioration.

Why do newspapers turn yellow over time?
Why is my white shirt glowing?

Whiter Than White - Fluorescence Effect

All color including white can be defined with a minimum of three numbers (learn more about the science of color - from Perception to Instrumentation, click here). What distinguishes white from other color is it’s high lightness and low saturation. It is more attractive with a bluish than with a yellowish cast.

Whiteness is caused by a combination of high lightness and lack of yellowness. Yellowness is usually undesirable in whites as it is associated with product deterioration. Whiteness with blueness is perceived as clean and therefore seems brighter.

High brightness is achieved with the aid of fluorescent whitening agents (FWA) or optical brightener agent (OBA). These are additives designed to enhance the appearance of brightness in fabrics, detergent and papers.
It may also enhance or modify the appearance of the white. FWAs increase the whiteness of a substrate by absorbing ultra violet light and re-emitting blue fluorescence. This overcomes the natural slight yellowness of the substrate to give an intense whiteness. FWAs are commonly used in washing detergents, paper and fabric. White paper and fabrics with FWA appear whiter than normal under UV illumination. Most commercial white fabrics are treated with FWAs. Similarly, washing detergents are formulated with FWAs to maintain the whiteness.

The paper samples below are illuminated by tungsten, TL84, D65 and UV lightings. Tungsten lighting has little or no UV energy and the FWA is not excited to make it flourescence. TL84 and D65 has some UV energy and the samples looked 'whiter'. Under UV lightings, the FWA are excited and produce a whiter than white look.

The spectrum graph shows an incremental amount of UV energy gives higher reflectance.

Color Matching Light Cabinets

Color matching light cabinet is a light booth designed to provide a standard set of lighting conditions for visual color inspection. The three most common types of light sources used in the world are incandescent, fluorescent and daylight. In theory, if the product color matches under these light sources in the cabinet, it will match in the real world.

Image: GTI Light Cabinet

Typically:

1. the daylight light source replicates the natural lighting - outdoor lighting
2. the incandescent for the tungsten light bulb and
3. fluorescent for the CFL light bulbs used for lighting up the office, mall and home.

Another light source commonly found in light cabinets is ultraviolet (UV) light. UV is used to observe the presence of fluorescence materials. The next time, when you are in a disco, observe how white fabrics glowed under UV lighting.

Light cabinets are used by manufacturers to ensure that their products matches in these lighting conditions and minimise color differences and metamerism.

The color difference between the zipper and the master color is larger under daylight than under tungsten light. Which means that it would look odd outdoor or in a place lit by fluorescent lighting.

Observe that the zipper has optical brightener agent (OBA) or fluorescence whitening agent (FWA) which causes the zipper to 'glow' under UV lighting whereas the master color has no OBA or FWA and under UV light (which has no color component), the sample looks 'black'.

This is not an optical illusion. It can be scientifically explained.

Welcome to the world of colors.

Going Green

Choosing the right light bulb can help save energy dollars. The choice is yours - flourescent light bulbs, halogen light bulbs or LEDs. Compact fluorescent lighting have become one of the most common energy saving devices on the market. Using CFLs instead of incandescent lighting can save you up to 20% of ultility bill every year.

The energy savings of LED lights can be huge. Assume that a traffic light uses 100-watt bulbs today. The light is on 24 hours a day, so it uses 2.4 kilowatt-hours per day. If you assume power costs 8 cents per kilowatt-hour, it means that one traffic signal costs about 20 cents a day to operate, or about $73 per year. There are perhaps eight signals per intersection, so that's almost $600 per year in power per intersection. A big city has thousands of intersections, so it can cost millions of dollars just to power all the traffic lights. LED bulbs might consume 15 or 20 watts instead of 100, so the power consumption drops by a factor of five or six. A city can easily save a million dollars a year by replacing all of the bulbs with LED units. These low-energy bulbs also open the possibility of using solar panels instead of running an electrical line, which saves money in remote areas.

Source: How Stuff Works

The Philippine Efficient Lighting Market Transformation Project (PELMATP), in cooperation with the Institute of Integrated Electrical Engineers of the Philippines, Inc. (IIEE) and City Government of Malabon held the Turnover of Lighting System and Ceremonial Switching on June 30, 2009 at Penthouse, 11th Floor Malabon City Hall.

The program was opened with the short messages from different personalities: Usec. Ramon G. Santos, DoE, Engr. Benjamic Villacorta. Malabon City Administrator, and Engr. Raymond A. Marquez, 2007 IIEE National President.

Read more about it.

Radiometry and Photometry

Lighting terms can be rather technical and confusing. This may help.

Radiometry is the science of the measurement of electromagnetic (EM) radiation. The broader spectrum covered by the science of radiometry is based on physical constants.

The properties of concern to us here are radiated power and its spatial and angular distributions. The four basic concepts are:

1. Radiant Flux
2. Radiant Intensity
3. Radiance
4. Irradiance

Photometry is defined as the measurement of electromagnetic energy that is visible to the human eye.

In 1942 the Commission Internationale de l’Eclairage (CIE) convened to define the response of the average human eye. They defined the Standard Luminosity Function also known as the Photopic curve and the Scotopic curve.

Photometric quantities are derived from radiometric quantities by utilizing a filter which approximates the behavior of the average human eye as defined by the CIE.

A radiometer is a device that measures the intensity of radiant energy. A majority of radiometers utilize only a single sensor whether photocell, photo-multiplier tube (PMT), etc. An optical filter is normally used when measuring radiation emitted from a specific spectrum or to incorporate the radiometer within a certain spectral response.

Radiometers are commonly used to quantify light or energy outside the visible spectrum, i.e., ultraviolet and infrared. Depending on the specific application, different filters with specific spectral responses are used.

A photometer is defined as an instrument for the measurement of visible light. The most common types are the luminance and illuminance meters.

The basic difference between photometers and radiometers is that the photometer incorporates a filter which follows the CIE Standard Luminosity Function Vλ curve (shown below).

Konica Minolta Sensing Inc published a booklet - The Language of Light which helps make the complicated lighting terminology simple for applicators.

Write to me if you need a copy.

Oh No!

Anna complained, “I tried out this pair of blouse and skirt at the fashion store and they matched but when I went to Cheryl’s wedding at the beach hotel, they looked awful, the colors do not match”.

Have you got this experience before, you tried out a nice outfit in a mall and when you wear them outdoors, the colors looked ‘off’? This phenomenal is known as Sample Metamerism, where two color samples appear to match under one light source and then do not match under another light source.

Most people experienced sample metamerism when putting on two different outfit where the colors looked similar in the mall where incandescent lights (warm lightings) are used but later found that they don’t match outdoors (which is natural lighting). Or they may not match indoors in the office lit by fluorescent lights.

Color has a spectral reflectance characteristics and lighting has color component and has a power distribution characteristics. By illuminating objects with lights of considerable differing spectral power distributions, metamerism will occur.

Incandescent lighting contains little blue light in shorter (blue) wavelengths and thereby is not able to bring out the blue colors of an object. And at the opposite end, the fluorescent lighting emits more short-wavelength light and this leads to two different visual difference.

On this note, when you are out buying lightings, check out the color temperature of the lights. It gives you an idea of the 'color' of the light.

Don't worry too much about metamerism with high end fashion. Garment manufacturers take lots of effort to use the right dyestuff to avoid this issue. In fact, these controls are done in fashion accessories, cars, white goods manufacturing to make sure you are not embarrased by 'mismatched' shades (the brand too).

Well, no harm trying out your next purchase under different lightings.

Happy shopping.

Crusing 100 Miles Per Hour

The alarm sounded and I opened my eyes and noticed that it was 5 am. Everything seems dark and I turned on the lights and my eyes instantaneously close as the bright light glare. It felt the same last night as I slipped into bed and the minute I turned off the light, I need to close my eyes before getting use to the dim surrounding.

This phenomenal is due to the design of our eyes. Our eyes have two types of light-sensing cells called rods and cones.

The cones are responsible for bright light vision and the rods for night time vision. Cones have a peak response at about 555 nano-meters and rods have a peak response in about 505 nano-meters. Because both the rods and cones have different sensitivities, they are represented by two different sensitivity curves called photopic curves (representing the cone) and scotopic curves (representing the rod).

Photometry involves measurement of the psychophysical attributes of electromagnetic energy that is visible to the human eye. Photometry is the science of human perception.

Now imagine that you are driving into a tunnel. Bright and sunny highway into a dark tunnel. And your eyes sensors switches from photopic to scotopic. Your eyes shut tightly as you adjust to the dark condition for a second or two. And if you do continue your journey, leaving the dark tunnel into the bright highway ....

This is a major concern for highway engineers. The next time you drive into and out of a tunnel, notice the lighting into and leaving the tunnel, they are specially built to make sure you don't close your eyes. It is not about the lights only, there are instrumentation to make sure that lighting levels are balanced according to the time of the day (or night).

Happy cruising.

Photometry becomes a modern science in 1942, when Commission Internationale de l'Eclairage (CIE) metto define the response of the average human eye. CIE measured the light-adapted eyes of a sizeable sample group, and compile the data into the CIE Standard Luminosity Function (widely known as photopic curve -chromatic perception at normal state, and scotopic curve - achromatic perception at low level of illuminance.