Natural light in Cezanne’s artist studio

Have you ever been half-way through a painting and suddenly the art studio light changes?

You carry on painting, hoping for a break in the weather, trying to remember the colour you’ve just mixed, and then the lighting changes.. again.

You think it won’t matter, it’s not that important, but the way you light your art studio can be one of the most cost effective ways of improving your painting and your colour mixing without buying another tube of paint.

One of the easiest methods of designing better lighting, is to simply change your light bulb.

But not all studio lamps are created equal.

From a £5 hardware store fluorescent tube to a £1,500 bespoke solution, the choices you make affect your ability to match colours accurately, judge skin tones effectively, and even feel a little happier by the quality of light you paint within.

With different options available you can have studio lighting the Old Masters would have been proud of…. without turning to shots of Absinthe.

Emergency chocolate biscuits needed

Trying to understand all the considerations when choosing my own studio lighting nearly led me to a lighting melt down! But bear in mind, I’m trying to design a bespoke studio where I’ll be painting 12 hours a day some days, through gloomy British weather and many a midnight painting session. So I need a space that has both natural light and the best quality artificial light.

There are so many variables and it’s such a specialist request that many Electrician’s will roll their eyes at you. With this tricky subject in mind, I have tried to created a summary of what you really need to know, and it can get a bit technical in places.

Do I really need to know this? I hear you cry!

Maybe, maybe not.

It depends on how much painting you do and your current lighting situation…

Artist studio lighting

As a painter I have worked in a range of studios with a variety of lighting, from the most fantastic natural brightness of light in the Mediterranean to orange incandescent bulbs that made my paintings look dull and dreary.

Finding a solution between natural lighting, artificial lighting and your budget can be a balancing act, depending on the subject you are lighting, your style of painting, space you have and funds available.

I’ve been struggling for years to find a simple, easy solution and have had many setbacks with my paintings along the way, trying to understand the difference between the lighting types, styles, colour temperatures,  Kelvin’s, CRI’s the list seems to go on!

I’m currently just finishing building my new studio and thought it was the perfect opportunity for me to address all the art studio lighting questions I’ve had in the past and put them into practice in my new studio space.

Picture hanging vs picture painting

Generally, the light you use in your studio is nearly always going to be different to the specific lighting arrangements of where the painting will finally hang and be viewed in.

I’ve painted subtle grey tones before, that look fantastic on my easel, but I know from experience they would almost disappear if hung in a hallway without natural light.

I tend to paint in quite a bright space, the same light illumination levels  you’ll usually find in an operating theatre, so when the paintings are displayed in a room with softer bulbs, the effect of the painting changes.

So, if you are commissioned to create a painting and have a chance of viewing the wall where the picture will hang, I’d say it is pretty critical to go and have a look.

It could be a bright conservatory or a dimly lit corridor and this can dramatically change how you approach the commission.

So what’s the best light to paint in? Let’s start with the artist favourite, North light.

The myth of North Light

All artists paint under North light, right?

That’s what we’re led to believe if you could only find the perfect window, the right size and the perfect height, that sends in soft North light, your paintings would be…perfect?

Not quite.

North light describes the location of the sun in the sky, having a window that only allows in North light helps to avoid having direct sunlight shine into the art studio while you work.

This is better for a painter because the light is more constant.

Notice how I didn’t say 100% constant, but more constant than the dramatic changes that happen with direct sunlight.

North light still changes.

Pro tip: North light only works if your studio is in the Northern Hemisphere, as a North lit artist studio in the Southern hemisphere will face direct sunlight coming through the window.

Windows and bounced light

The first thing to look at is where your window is.

Ideally, you would want a North facing window above your easel at about 35° angle from your canvas, so you get directional light on the canvas without getting glare.

Glare is most prominent if you are painting vertically with oil paints.

Photo: Perry Ogden, Francis Bacon’s studio – notice the position of the easel in relationship to the window

My studio halfway through the build – the side of my studio is North facing so I’ve installed 3 large Velux ceiling windows on a pitched roof

This gives me a nice spread of natural light if I’m working with the window light directly behind me or to the left side of me as I’m right handed so the canvas is always illuminated, similar to the position of the easel in the Rembrandt studio below.

If you have a large North facing window that is low (like Cezanne’s window light in his studio above) you have to be aware of bounced light.

This is where light from outside is coming in from the bottom of the window and then hitting the top of the ceiling in the studio – reflecting light from the ceiling down into the space.

If you’re trying to create a strong directional light effect, the reflected light from the ceiling can lessen the strong contrast, also, if you have any colour on the ceiling this will be reflected into your studio.

You just need to add a ‘hood’ over the top of the window to stop the light spilling up into the ceiling.

It’s like adding a barn door to a photography studio light – you’re just controlling the light coming into the space.

Depending on where you live in the world, the intensity of the light will vary, so a bright summers day in Italy, will be much more intense than a summers day in the UK.

Impressionistic or Classical?

If you paint in a more Impressionistic style, like Cezanne, reflected light can add to your set up, illumination of the space is your number one priority.

However, if you are only going to be creating highly dramatic, Chiaroscuro Old Master style lighting, then reflected light can pose problems.

You can go completely black in the studio, black walls, black ceilings, black floor, black clothes! but if you don’t manage reflected light then it can defeat the whole object of creating a space lit with one single light source.

Rembrandt’s Art Studio lighting – Look at the low blackout windows and the canvas hood that prevents the light bouncing on the ceiling. You can read about my visit to Rembrandt’s studio here.

So, if you have a large low window, generally the bottom half should be covered with diffuser fabric so you get only light coming into your studio higher up, helping to illuminate your canvas without casting shadows.

Black out roller blinds can be very helpful in controlling the intensity of the light, the smaller and higher the light source, the more half tones you see in the subject.

Now we begin to enter the realms of artificial lighting.

What is colour temperature?

Have you ever seen a chameleon change colour?

Well, this is how light changes throughout the day, depending on the time of year, weather, and if you’re in the Northern or Southern hemisphere.

Just as different paint colours are called warm and cool, so are different light sources. And this can effect how you perceive colours in your studio.

With natural daylight, the changes happen subtly throughout the day, so initial colour change isn’t always apparent. However, when you’re concentrating and trying to paint a subject, you are battling against the perceived colours that keep changing!

This is why in Monet’s Haystack series he worked on numerous canvases as every couple of hours the light changed.

I overcome this in my studio by painting under a combination of natural and artificial light. For these to marry together we need to aware of the range of colour temperature of bulbs (often referred to by electricians as lamps)

Colour temperature

If you were to heat carbon to 2426.85 degrees Celsius it would have a Kelvin of 2700K, and would glow yellowish-white.

If you heated carbon to 5126.85 degrees Celsius it would have a Kelvin of 5400K, and would glow bluish-white.

So the higher up the Kelvin scale (colour temperature) we go, the cooler and more blue the light.

So a lamp with a Kelvin of 6500K would be called a cool light.

So how does this relate to North light?

The kelvin of north light

The most common colour temperatures of light are as follows:

• A regular household incandescent bulb – 2,500K – 3000K and gives a nice warm light

• Office fluorescent light – 4,000K – 5000K and gives a cleaner, cooler light

• Noon Daylight – 5,500 K

• North Light (blue sky) – 7,500K -10,000K

North light varies depending on if you live in the Northern or Southern Hemisphere, but in general North light/ blue sky is around 7, 500 – 10,000 Kelvin and if you were to mimic this is a lamp would be far too blue/cool to paint with.

In my studio, because I need artificial light as well as natural light I aim for a lamp of between 5000K – 5500K, this gives a white light rather than it having a cast of being too blue or too orange.

But just relying on Kelvin isn’t the only consideration, it’s number 1 on your tick list but you could buy a cheap bulb with a 5000K but if it hasn’t got a full spectral range, referred to in the industry as a CRI rating, then it might not be as accurate as you think.

CRI (pronounced ‘cree’ not C.R.I like F.B.I as I first thought!) stands for Colour Rendering Index.

This is the ability of a light source to render a full spectrum of colours to our eyes.

Colour rendering index CRI

So, the next thing we have to consider when choosing a lamp is the colour-rendering index (CRI), this indicates a light’s ability to illuminate colour accurately.

Natural daylight has a CRI rating of 100, this is what ideally we’re aiming to mimic in a lamp.

The more balanced the rendering results are, the higher the CRI will be.

Pro tip: ‘Full spectrum lighting’ is a phrase used by the lighting industry to denote bulbs that mimic the properties of sunlight, but some bulbs/lamps described this way perform better than others. So for example, you could have an artificial light source that renders blues and reds accurately but doesn’t have a strong yellow in its spectral curve so the rendering of the yellow will be duller.

Here you can see this has a very spiky, spectral curve, so doesn’t offer an even colour rendering.

Colour is created by the selective reflection and absorption of the colours in the visible spectrum by the painting’s pigments.

This is really important for the lighting in your studio so you can mix a full range of colours accurately.

The higher the CRI score (out of 100) the more accurate to a full spectrum colour, the light source. Bulbs with a CRI of 80 to 100 are best at revealing vibrant, natural hues.

With artificial light, we’re looking for a light source that is ideally over 90 and as close to 100 as possible. Different lamps have different colour rendering indexes. This indicates how smooth, or how ‘spiky’ the light source is. If the source has spikes in it or is not well balanced you get an illumination that has flat rendition of some colours.

Just as a note, the highest CRI rating lighting manufacturers produce with a 5000K – 5500K is currently around 98.

Pro tip: The correlated color temperature (CCT), measured in Kelvin, refers to how warm or cool a light appears. Too warm a bulb may tint work reddish yellow, whereas too cool a light can turn things blue. For a good balance of warmth and coolness, look for bulbs with a CCT of 5500 K, the equivalent of midday sun. If you prefer cooler light, akin to north light, look for bulbs rated 6500 K.

Lumens, lux & light output

And finally but very importantly the next (and almost last) thing to consider is luminosity or brightness.

This is different to Kelvin or CRI, this is the lamps lumen rating or wattage rating.

What are lumens?

Watts measure the amount of energy required to light products, whereas lumens measure the amount of light produced.

The more lumens in a light bulb, the brighter the light.

Using lumens helps you to work out how bright the space will be, regardless of the type of lamp you are using.

For example: You could have a LED down-light, a Compact Fluorescent Lamp and an Incandescent bulb that all have different wattage per bulb but by using Lumens you can work out the light output produced.

• 40-watt incandescent bulb = 450 lumens
• 29-watt Halogen = 450 lumens
• 9-watt LED = 450 lumens
• 9-watt Compact Fluorescent Lamp = 450 lumens

So to clarify, generally, total light output from a light source, regardless of the direction the light travels, is specified in lumens (lm).

So can I just find a handy lumen comparison chart to see how many lamps I need for my studio space?

You would think!

But there are so many variables that there isn’t a one size fits all and to complicate it further to describe the amount of light that hits a specific surface eg: your canvas, another term is used called Lux or Footcandle depending if you work in meters or feet.

Lux is defined as the level of brightness at a particular distance from the light source.

So the further from the light source the less the Lux level.

The formulas for measuring how much brightness you will need in your space are complicated, I found trying to work out light fallout, ceiling height, diffusers on lamps, beam spread etc.. really difficult to calculate!

Simplest solution

My top tip for lighting a small art studio with a ceiling height of 8 – 10 foot, is a bulb you can just screw into your existing fitting and is a Compact Fluorescent Bulb.

It should have a 90+ CRI rating, 5000K- 5500K colour temperature and around 85 watts, it will give a light output of around 5000 lumens at the lamps source and will give you a bright, clean light to work under.

Pro Tip: The light strength diminishes as the light is moved further from the source so by the time it hits your canvas it would probably be a 2/3 of the strength, around 1,800 lux – based on you sitting 1.5 meters away from the lamp in the ceiling.

The recommended lux level for detailed drawing work or very detailed mechanical work is 1500 – 2000 lux so this would fit the bill! Hurray!

However, 1500 lux is still very bright and I would imagine for most home studio situations, this bulb would give out ample illumination.

For many classical paintings, a lux level of 250 – 450 lux can still work very well, especially if your finished piece is going to be hanging in a darker space.

The lux value changes depending on how far away from the source you are painting, the angle of the beam etc.. but this lux calculator is very handy if you want to check your own studio and find a light level that works best for the style of work and type of paintings you are going to be creating.

Lux can be measured by a Lux meter if you want to get super pro

A brief lamp overview

Here’s my overview of lighting and how to choose the best solution for your own space.

Incandescent Household Lamp

These are very inexpensive, have a high CRI rating 95+ but are a very warm light resulting in you actually painting things cooler than you would like, not the best choice for an art studio. Incandescent light bulbs are being phased out in favour of more energy-efficient lighting.

Compact Fluorescent Lamp (CFL)

A compact fluorescent lamp (CFL) is a type of fluorescent lamp. Many CFLs are designed to replace an incandescent lamp and can fit into most existing light fixtures formerly used for incandescent light bulbs but generally use less power, have a longer rated life and give the same amount of light, but at a higher purchase price.

They generally have a lower CRI rating of 80 + (you can find odd ones that are higher) but Kelvin can be 5000K – 5500K.

CFLs radiate a different light spectrum from that of incandescent lamps, but are becoming more similar in colour output to the standard incandescent light bulb.

Halogen Lamp

A halogen lamp consists of a tungsten filament sealed in a compact transparent envelope filled with an inert gas and a small amount of halogen such as iodine or bromine. The halogen iodine or bromine increases the lifetime and the luminous efficiency of the lamp. Halogen lamps reach a luminous efficiency of approximately 25 lumens per watt (a conventional incandescent light bulb is approximately 15 lumens per watt and a compact fluorescent lamp is approximately 60 lumens per watt).

Halogen bulbs are smaller than conventional light bulbs and usually found in recessed task lighting, CRI is high but colour temperature is usually very warm.

Full Spectrum Halogen Lamps

Want to light your painting like the Mona Lisa?

Then you need to invest in some Solux bulbs.

These bad boys are used in museums globally, such as The Louvre in Paris, Guggenheim Museum, NY & The Van Gogh Museum to name a few. The CRI rating and spectral curve is amazing and for artificial lighting that best illuminates natural daylight, you can’t get much better.

So, have we found the perfect solution?

It depends.

If you work small and have a friendly electrician these can be a great solution, there is a 4 lamp track available that gives a great value spread light, however, the halogen light has a spot effect, rather than bringing up the illumination of the room.

So for lighting the Mona Lisa, perfect.

For creating an ambient light in your studio?

Harder to achieve.

The lights are often used for photography proofing of colours, so have been designed on a track system for illuminating a wall.

The halogens also run hotter than the fluorescent’s and use a touch more energy. Also they are harder to track down in the U.K.

Solux bulbs are the best halogens on the market, but they are expensive compared to lifespan/ cost ratio of fluorescent bulbs.

Pro Tip: They produce an amazing reading lamp for a lovely quality of light.

Full Spectrum Fluorescent Tubes

These tubes are probably the next best thing indoors to North light for most artists wanting a good illumination of the whole space.

They are relatively cheap and efficient and have good color indexes on the more expensive tubes.

The light source of a fluorescent tube is mercury and the light that mercury produces gives of ‘spiky’ lightwaves, the light isn’t an even spectral curve.

To combat this, manufacturers coat the inside of fluorescent tubes with a phosphor coating.

The phosphor coating helps to smooth out the spiky light wavelengths and gives a more even spread of colours.

So for lighting an artist studio we’re looking for a tube with a ‘tri-phosphor’ coating.

Good quality ‘triphosphor fluorescent’s use three phosphors to give off red, green and blue light. This tricks your eyes into thinking they are seeing white, in much the same way as a TV screen works.

Specialist fluorescent’s are available with a CRI higher than 90%, but these are slightly less efficient and are usually only used by professionals such as graphic designers or artists.

I will be using full spectrum fluorescent’s to light my studio, the lamps I’m going to go for are Philips TL-D 90 Graphica Pro Triphosphor 4′ T8 36 Watt Fluorescent Tube 36W,

They have a Kelvin of 5300K and a CRI of 98 and I can create a bank of lights to mimic diffused daylight whilst ensuring the lux level is going to be high enough.

On a happy note, as the bulb mimics natural daylight it’s ideal for sufferers of Seasonally Affected Disorder or S.A.D, so gives a feel-good factor whilst you work!

A note on fluorescent lamps

In fluorescent tubes, there is a number that represents the diameter of the tube.

The tubes I’m using are called a T8 and the industry are in the process of phasing them out, along with the T12 in favour of more energy efficient bulbs.

The T5 and LED’s are the alternatives but I’ve yet to find either that offer a high enough CRI rating, however, I believe over the next couple of years with developments in manufacturing there will be a more energy efficient like for like replacement.

Phew! hope it helps with setting up your art studio space.