Computerised lighting

2 March 2011

In theory computer software should make the lives of lighting designers easier, but the reality is often very different. Nick Martindale examines whether the latest developments could change that

For lighting designers, the appeal of using software packages should be obvious. Such software allows designers to demonstrate ideas to clients using a format that is common across the industry, while taking into account the unique characteristics of specific projects.

For years though, designers have wrestled to incorporate luminaires into CAD packages that were designed for an architectural client base.

Not convinced

Lorraine Calcott, director of It Does Lighting and Energy Ltd, says she tends to bypass CAD products from a design perspective, using them only to import drawings from design packages, enabling her to send on files to clients.

“I don’t find them that easy to use from a lighting perspective,” she admits. “They try to cover so many different disciplines that they’re not always as lighting friendly as I would like or as accurate, for example in totting up the quantities of fittings correctly.”

“I DON’T FIND CAD PACKAGES THAT EASY TO USE FROM A DESIGN PERSPECTIVE”
LORRAINE CALCOTT, IT DOES LIGHTING

Antony Tyson is assistant lighting designer and CAD operator at Lighting Force. He finds CAD packages an integral tool for his job and says the models on offer are improving all the time. But there can be obstacles. “My biggest issue is with linear sources such as T5/LED profiles,” he says. “Often they do not have a continuous distribution along their length, but instead are a series of point sources.

This is fine if it’s a pendant, but we often position them near walls and then you end up with a series of hotspots rather than a continuous line of light. Clients almost always pick up on that.”

Another item on his wish list is extended calculations that result in photorealistic dynamic 3D outputs, rather than just individual views.

Francesco Anselmo, senior lighting designer at Arup, Picture this Last year Dial unveiled its new Dialux plug-in. This screen shot shows how false colour rendering lets designers analyse the expected luminance throughout a space highlights the need for packages to link to and from information models as a key requirement for the future.

Where they do offer this functionality it tends to be more from a visualisation than an analysis perspective, he says.

This means designers end up questioning both the figures and the look of the end product.

“It’s more focused on getting a pretty picture than analysing whether the lighting solution works,” he says.

“There is a workflow there that could be adapted from a lighting design perspective, but software companies need to put a lot of effort into streamlining and facilitating the integration of lighting design with the tools.”

Light in the dark

In light of this, many designers prefer to use specific light planning software, whether that be free products provided by manufacturers, or a paid-for package created by a dedicated provider.

Last year, Dial unveiled its first lamp plug-in that lets designers access data on lamps using the luminous flux, which would be expected in practice, including variables

Free and easy Holophane’s free Visual package is all the design software many people need such as light colour, colour rendering and performance data such as light loss and failure probability. The plug-in is currently available through Osram but both Philips and Megaman are preparing their own versions.

Dieter Polle, MD of Dial, says the new Dialux plug-ins were designed to help designers who have to manually enter specifications from a paper catalogue when choosing luminaires from electronic catalogues.

“The luminous flux of the lamp as provided by the manufacturer is in most cases only a medium value,” he points out. “It is almost impossible for a luminaire manufacturer to provide and constantly update details for the wide spectrum of lamps available on the market. It is now finally possible to bridge this gap in the workflow of the light planner. The performance data of all lamps currently available on the market are now just a mouse-click away.”

Current limitations

The market so far, though, has given a mixed reaction. “The plug-ins for Dialux models allows for more meaningful results to be produced,” says Theo Paradise Hirst, lighting consultant at NDYLight, whose team uses Autodesk’s Revit 2011 (3D CAD) package. “But at the moment it is not possible to apply easily critical variants such as special lenses, special reflectors and adaptations, so specialist lighting consultants will quickly find limitations. However, lamp plug-ins are definitely a step in the right direction.”

Tyson adds: “The plug-in looks fi ne but I have to say I have never found the problem it’s solving to be much of an issue.

“It would make things slightly faster but the Osram book next to me is nearly as quick and you only ever usually have to select a handful of luminaires.”

Calcott, meanwhile, says Holophane’s free Visual package is perfectly adequate for her needs, complemented by Dialux and Philips’ Calculux product, while Tyson is a fan of the free software offered by Relux.

SOFTWARE COMPANIES NEED TO STREAMLINE THE INTEGRATION OF LIGHTING DESIGN WITH THE TOOLS.”
FRANCESCO ANSELMO, SENIOR LIGHTING DESIGNER AT ARUP

Ultimately, lighting designers will always have their own favourites and ways of working, dictated as much by their budgets and those of their clients as any new functionality.

“It’s no good see-sawing all the time because one package has had a marginal improvement over the other,” says Tyson.

“I would consider paying for, or persuading the company to pay for, a program but it would have to be very good because the free options are so sophisticated.”

NO SUBSTITUTE FOR EXPERIENCE

Even with new software developments taking place all the time, lighting designers are never likely to be able to rely entirely on computer-generated results.

“We always take results with a pinch of salt,” says Antony Tyson, assistant lighting designer and CAD operator at Lighting Force. “Even if they were 100 per cent accurate they would always be dependent on factors which exist within certain tolerances – maintenance factors, reflectance, lamps, luminaires, dimensions – and all this can vary between planning and execution.”

But Lorraine Calcott, director of It Does Lighting and Energy, worries that some designers fail to go to see completed installations in the flesh once they havefinished their design.

“I was very lucky when I was getting into lighting, I had a boss who made sure we played with light fittings and saw the different effects we could get with them,” she says. “I still ask for samples of things before I spec them because I like to see with my own eyes what they can do and I like to have a play about with the fittings.”