Lighting design is partly a mathematical process and partly a series of assumptions based on the needs of the user. Taking a priceless piece of ART for example and transforming it so the client sees it in a different way, is a result of a tremendous amount of work and research, where the lighting scenario will allow the art work to take a center stage.


Choosing lights for your project can be quite technical.

Either you are building an apartment, a new home, a restaurant, a hotel, any kind of commercial business, or an art gallery, it is important to understand the different aspects there are to lights such as the Color Rendering Index, and why it’s so important to achieving your goal in your project.

With the advances in LED technology, there are many LED light sources on the market that could potentially light your project.But, before splashing out your cash, you need to find out not only that the LED you have in mind is bright enough and has an appropriate optical performance but, more importantly, the color performance of the LED. What is its color temperature CCT ( Correlated Color Temperature ) and does it have a high CRI rating of Ra 90+ (color rendering index)?

If the LED on offer has a CRI of between 85 and 90 it can be described as having ‘good color rendering’.90 and above is ‘excellent color rendering’ and that is where you need to be to get your art work to look at its best.100 is the PERFECT scenario.

For some lighting design can be an afterthought or just simply misunderstood. If you are opening a restaurant, for example, you might want dim lighting which might work great for your space—but it might also create a different environment from what you intended. Or, if you are an artist and are hanging your work in a gallery, the lighting will affect the way your painting is seen by customers and visitors. These risks can easily be solved by understanding CRI-here are some key things to know.

CRI essentially refers to how different types of illumination, or light, affected the color of objects as they are perceived when the light hit them. The index provides lighting manufacturers to create different lights with CRIs that are best for different situations, i.e. a restaurant and an art gallery. To do this, they manufacture lights on a scale of 1-100:

High-pressure sodium light sources have a CRI 24

Mercury vapor light sources have a CRI around 49

Fluorescent light sources have a CRI range between 50 and 85 depending on the phosphate coating of the bulb

Metal halide light sources have a CRI range between 75 and 95

Poor quality LEDs the majority of what the market is using have a CRI range between 55-75

High-quality LEDs have a broad range of CRI up to 95

What do those CRI measurements mean? Simply put, the lower the CRI, the less accurate the true colors will be depicted. Therefore, if you are shining a light on a table where your food will be placed, you’d want a higher level CRI. The same goes for a piece of art, a mosaic installation, a Corian sculpture—if the light shining on your object or photo has a low CRI, the colors that you used or captured are not going to appear as you intended. The closer the CRI rating is to 100, the more the colors will appear as they would in perfect natural, true lighting.


You also have to be aware that the final lighting result will be influenced by different reflectance levels and the light loss the interior objects will cause after their installation in an interior space.Lighting design by the majority of the specialists is a procedure that ends when the lighting installation is over. WRONG!!

All the interior objects absorb light. It is then when we really have to do new calculations lighting adjustments.

There are cases where the lighting designer is also an architectural interior designer as it is in my case. So we have calculated the color of the interior surfaces during our interior design study and when we are working with our lighting concept-scenario we use those results in our lighting study, therefore we are not dealing with major changes until the end of the project. But it is really rare to find an architectural interior designer who is also a lighting designer. What you have to keep in mind is that the lighting calculations should be continued until the last interior object is installed.

Lighting design is the most powerful MARKETING asset in any type of a commercial, hospitality, residential, art exhibition project you might have.

The revenue the right lighting scenario can cause is immense.

I dedicated all my life studying architecture and interior design. It took me forever to study lighting design. What I still don’t understand is why people are hiring the most qualified architects and interior designers and why they pay for luxurious interior design materials, ( expensive marbles, mosaic, leathers, Corian, Swarovski, art work e.t.c ) if they are not planning on hiring a lighting designer to make sure that all those luxurious visual ” stimulations ” would be perceived in their eyes and the eyes of their customers, they way they should?

So it became my passion. My addiction. To educate my clients and to illuminate correctly their businesses. I turned to be a great Marketing asset and a powerful weapon in what they are trying to accomplish. Success in every possible way.

Marianna Holoway
Architectural Lighting & Interior Designer