Dummies Guide to Art Gallery Lighting
Rule Number 1: Colour Rendering Index
You should aim for your lighting to have a minimum CRI of 90+
Colour rendering Index is a meaure of how well a light reproduces colours on a scale of 1-100.
Wikipedia says:
A color rendering index (CRI) is a quantitative measure of the ability of a light source to reveal the colors of various objects faithfully in comparison with an ideal or natural light source. Light sources with a high CRI are desirable in color-critical applications such as neonatal care and art restoration.
Lights nowadays typically have a CRI of 70-80 - this is not high enough if you really want to see colour.
Light colour measured in Lumens
This is a personal choice. 4000K is normally referred to as Cool White. It's the colour you will find in many high street stores such as White Company. 3000K is Warm White and is a more comfortable and subtle light. 2700K is very warm white and preferable for your sitting room at home.
How much Light? 400-450 Lumens is the amount of light typically emitted by the 50mm GU10 recessed downlights in your kitchen - it is NOT ENOUGH in a dedicated art gallery!
A quick word on GU10 lamps. The label GU10 refers to the two twist fit lugs which make the connection to millions of small lights worldwide. These small lamps were made for halogen technology which has been superceded by LED equivalents. They were very hot when they were powered by halogen and indeed halogen is better at heating than lighting!
When LED became a feasible lighting source, manufacturers shoe horned LED chips into the GU10 body even though it wasn't designed to do that and there lies the problem, it's a compromise and not designed from the ground up to be a good lighting source.
Modern top quality lights for use in commercial situations use Chip on Board (COB) technology and large reflectors and lenses for much more and better light of 3000 Lumens and more.
Dimming LED's
Yes dimming is possible but dimming is not like it used to be in the days of incandescent lamps. Then dimming was acheived by reducing the amount of voltage going through what was essentialy a glowing hot wire inside a glass enclosure with some gas swirling around inside.
If you do that to an LED it will flicker and die because it needs full power whether dimmed or not.
LED's require a driver to make them light up, sometimes these are enclosed within a lamp, sometimes fitted alongside in a box and some remotely on the end of a wire. Drivers are electronic and some are dimmable, some are not. Guess what? The dimmable one's are more expensive!
Beam Angles
People have difficulty imagining the effect of beam angles. You can think of it in the following way: A narrow spot of up to 20 Degrees is like the spotlight you see in the theatre following a single actor across the stage. Everything going away from that illuminates a wider and wider pool of light until it lights up the entire cast of 100.
Want to know more? Just give us a call on 0207 183 5252
You should aim for your lighting to have a minimum CRI of 90+
Colour rendering Index is a meaure of how well a light reproduces colours on a scale of 1-100.
Wikipedia says:
A color rendering index (CRI) is a quantitative measure of the ability of a light source to reveal the colors of various objects faithfully in comparison with an ideal or natural light source. Light sources with a high CRI are desirable in color-critical applications such as neonatal care and art restoration.
Lights nowadays typically have a CRI of 70-80 - this is not high enough if you really want to see colour.
Light colour measured in Lumens
This is a personal choice. 4000K is normally referred to as Cool White. It's the colour you will find in many high street stores such as White Company. 3000K is Warm White and is a more comfortable and subtle light. 2700K is very warm white and preferable for your sitting room at home.
How much Light? 400-450 Lumens is the amount of light typically emitted by the 50mm GU10 recessed downlights in your kitchen - it is NOT ENOUGH in a dedicated art gallery!
A quick word on GU10 lamps. The label GU10 refers to the two twist fit lugs which make the connection to millions of small lights worldwide. These small lamps were made for halogen technology which has been superceded by LED equivalents. They were very hot when they were powered by halogen and indeed halogen is better at heating than lighting!
When LED became a feasible lighting source, manufacturers shoe horned LED chips into the GU10 body even though it wasn't designed to do that and there lies the problem, it's a compromise and not designed from the ground up to be a good lighting source.
Modern top quality lights for use in commercial situations use Chip on Board (COB) technology and large reflectors and lenses for much more and better light of 3000 Lumens and more.
Dimming LED's
Yes dimming is possible but dimming is not like it used to be in the days of incandescent lamps. Then dimming was acheived by reducing the amount of voltage going through what was essentialy a glowing hot wire inside a glass enclosure with some gas swirling around inside.
If you do that to an LED it will flicker and die because it needs full power whether dimmed or not.
LED's require a driver to make them light up, sometimes these are enclosed within a lamp, sometimes fitted alongside in a box and some remotely on the end of a wire. Drivers are electronic and some are dimmable, some are not. Guess what? The dimmable one's are more expensive!
Beam Angles
People have difficulty imagining the effect of beam angles. You can think of it in the following way: A narrow spot of up to 20 Degrees is like the spotlight you see in the theatre following a single actor across the stage. Everything going away from that illuminates a wider and wider pool of light until it lights up the entire cast of 100.
Want to know more? Just give us a call on 0207 183 5252