The Pro-Lite Blog

Pro-Lite Wall Planner

2009 Wall Planner Published

20 October 2008: We've published our 2009 wall planner. if you are an existing Pro-Lite customer you will receive your copy in the post soon. If you are not, fear not - just drop us a line and we'll be happy to send you a copy complete free of charge. The best things in life truly are free.

The wall planner is an A1-sized chart with useful technical reference information on laser safety and photometry.  Click here for a preview.

» Request a copy
Selfridges Building, Birmingham 

Are You Seeing Red?

17 October 2008: A recent article in Lighting Magazine caught our eye. It refers to the lather that the Daily Mail got itself worked up into at the alleged lack of patriotism of the Selfridges store in Birmingham (pictured opposite).

The Selfridges building is a standout landmark in the regenerated Birmingham. At night, it is normally illuminated in blue. On other occasions, the building has been illuminated in various other hues (pink, gold and green) to mark special occasions such as Gay Pride and St Patrick’s Day. The Daily Mail argued that the building should be illuminated in red to mark St George’s Day.

Unfortunately for the Mail journalists, the laws of physics prevent Selfridges from honouring the English patron saint. The building is indeed illuminated with red lamps, but the spectral reflectance of the tiles on the building preferentially reflect blue wavelengths. Hence the building appears pink.

This is a perfect illustration of the problems lighting designers have in achieving good colour rendering. Colour rendering is one of the topics we cover in our Practical Light and Colour Measurement Course, delivered in association with Birmingham-based Photonics Cluster.

» Click here to learn more about the course
Bentley Flying Spur Interior 

Making the Best Better

26 August 2008: Bentley Motors produces some of the finest motor cars in the world. Bentley provides a very high attention to detail in the design and production of their vehicles, and this exacting approach extends to the selection of the photometric test equipment which they needed to help in the development of its cars’ interior and exterior lighting, instrument panels and infotainment displays.
 
Bentley has embraced advanced, solid state lighting (SSL) based upon light emitting diodes (LEDs) in its vehicles. These are used extensively for display backlighting, for subtle mood lighting in the cars’ cabins and for illuminating switches and panel indicators. For Bentley, it was vital that the LEDs selected provide consistent illumination, create the required level of brightness (luminance) and emit exactly the desired colour. Visual comparison of the LEDs is extremely subjective and simply cannot quantify the performance of the light source or display. Traditional “spot” photometers – light meters which measure the brightness and colour of a display one (small) spot at a time were one answer, but Bentley needed a more productive solution.
 
The solution selected was an Imaging Photometer – specifically a ProMetric™ CCD Imaging Photometer made by Seattle-based Radiant Imaging Inc and distributed in the UK by Pro-Lite. ProMetric photometers are powerful, CCD-based light and colour measurement instruments that provide for vastly increased productivity compared with traditional “spot” photometers. Whereas a spot photometer can only measure the brightness and colour of one point on a display or light source at a time, a CCD-based ProMetric photometer can measure millions of points simultaneously. Moreover, because the ProMetric camera views the whole light source at once, localised luminance and colour differences can be easily detected – artefacts that simple spot meters would probably miss.

» Learn more in our Case Studies area
Car Headlight 

Helping Ring to See the Light

26 August 2008: Ring Automotive Ltd is a market leader in the automotive lighting aftermarket sector. The company needed a way of comparing the illuminance, chromaticity and colour temperature of their aftermarket bulbs in order to establish their performance benefits. In addition, Ring needed a means of qualifying its lighting products and of assessing the performance of their lamps against the requirements specified in the applicable UN ECE R20 vehicle lighting regulations.

Traditionally, the illumination performance of a headlamp has been determined using a goniophotometer. This type of instrument places the headlamp on a motorised stage that rotates and tilts the headlamp with respect to a photometer that views the headlamp along a fixed direction of view. Goniometric headlamp measurements are normally performed in a dark room at a distance of 25m. The photometer records the illuminance from the headlamp one angle at a time, an accurate but slow process.

Ring turned to Pro-Lite for a more productive solution. We proposed a ProMetric CCD imaging photometer which can measure millions of angles simultaneously. Moreover, because the imaging photometer views the whole illumination pattern at once, localised illuminance and colour differences can be easily detected – artefacts that goniometric measurements performed at defined angles might easily miss.

The productivity of the imaging photometer was further enhanced with the development of software to automate the testing of beam patterns in accordance with ECE regulation R20. The software automatically determines the datum position (“beam elbow”) in the illumination pattern, aligns the camera image to this position, measures the illuminance at the ECE R20 specified test points for left or right hand drive and provides for simplified pass/fail type reporting of the device under test.

» Learn more in our Case Studies area
Integrating Sphere 

A Simple Solution to Complex Light Measurements

8 July 2008: The integrating sphere was originally invented in 1892 by British scientist W E Sumpner, while the first integrating sphere was built by German scientist R Ulbricht in 1894. In Germany, the integrating sphere is still known as the Ulbricht Kugel. Today, integrating spheres are widely used to simplify the measurement of light sources, in calibrating imaging and remote sensing equipment and in testing the optical properties of materials.

An integrating sphere is a hollow, spherical chamber painted internally with a matte, high reflectance coating. Integrating spheres provide alignment-insensitive collection of extended area light sources when combined with a photodetector. When internally illuminated, an integrating sphere provides a uniform luminance or illuminance field for flat-fielding cameras and electronic imaging systems. In reflectance measurements, an integrating sphere allows all of the scattered light to be collected rather than just the specular component.

» Learn more about integrating spheres