Tuesday, August 26, 2008

Studio Lighting

Whatever your studio situation, it helps to work under a good volume of color-balanced light, and there are many ways to set it up.

Regular incandescent lights peak the orange and red wavelengths, and tends to be weak on blue. That’s why red colors in your picture look so good—and blue colors look so dead—under normal incandescent light. Some artists prefer to work under an array of halogen or blue-tinted incandescent bulbs, which can give excellent light, and which simulate the track lights used in galleries and museums. The downside of incandescent is that it uses a lot of electricity.

Standard “warm white” and “cool white” fluorescent lights overemphasize yellow-green. They’re made to give the most light in the range of wavelengths that the human eye is most sensitive to. If you’re using flourescent light, try to select "color-balanced" or "full spectrum" bulbs (such as Vita-Lite or Verilux brands) with as high a “CRI Index” as possible. The color rendering index is a measure of how well artificial light simulates the full range of wavelengths in natural sunlight. The quality of light that a fluorescent light delivers depends on phosphors that the manufacture uses to line the tube.

A measure of this color output is the graph of “spectral power distribution,” which any specialty lighting salesperson should be able to show you for a light you’re considering. It’s not as technical as it sounds, once you start comparing these charts.

The simplest solution, popular with art students, is a “Luxo” type lamp that combines fluorescent and incandescent light.

In my studio now, I have a north window to my left (because I’m righthanded). In the daytime, I turn off the fluorescent lights and use the natural daylight. North light is the traditional artist’s studio lighting, but I find it to be a little too cool and variable on its own. (By the way, note the mirror to the left of the curved window, for getting a fresh eye.)

Some artists in the past used sunlight from a south-facing window diffused through white cloth. This is a great solution, because it’s free and abundant. The best cloth I’ve found is white ripstop nylon from the fabric store. The window should be blocked off on the lower half so that the glare doesn’t go into your eyes while you're working.

This inspired me to diffuse the light from an overhead skylight as a supplement to north light. Directly above the work area is a four-foot skylight opening. The opening channels the light from two skylights, one on each side of the roofpeak. The skylight well is lined with Mylar-coated card stock that I found at a craft store. This reflective lining bounces and multiplies the sunlight that finds its way into the skylight well. The direct sunlight is diffused into a white nylon panel held in place with a homemade square frame of PVC tubing.

Flanking the skylight are fluorescent fixtures with 12 four-foot color-balanced bulbs.
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Wikipedia on Spectral Power Distribution, and Color Rendering Index
Color output chart courtesy Salsburg.com.
Incandescent chart from Neon.com

13 comments:

Erik Bongers said...

That's a studio setup that probably most of us dream about!

DavidStill said...

So on a wavelenght chart like the ones you posted, do I want as straight a line as possible?

Julian Merrow-Smith said...

Digital photo lights, readily available on ebay are great for night time painting and as supplementary lighting during the day, they are pretty cheap now and a set of adjustable lamp stands with 160 watt standard screw fit (5400-6500k) bulbs and a nylon fold up light box for photographing your work can be had for well under $100. Having said that James your set up looks ideal. My windows face east so mornings are a problem but I find on overcast afternoons the studio lights fit in with the daylight with no off color shadows.

JMahorney said...

Great post and I think about this stuff all the time. Problem is I'm still confused about what to actually put in my still life light stand and my paint box light. Right now I use halogen because I have found them less orangy. The daylight bulbs from home depot are just incandescent covered with violet coating. So in short, what should I put in my lamps? Something like a solux bulb?

James Gurney said...

David, Yes, natural sunlight would be closer to a straight line, or an even distribution of output across the spectrum. Studio north northlight would peak toward blue.

Thanks for mentioning that digital light setup, Julian.

JMA, If you're going to use incandescent, the halogens are good on color. I have a friend with four halogens over his easel. By having four lights you don't get a single dark shadow. Fluorescents with a diffuser panel gives a softer light without hard-edged shadows.

I forgot to mention in the post that if you're painting a figure or still-life, it helps to have a light with a similar color temperature to the one on your subject, or else it's really hard to judge colors.

Alandiras said...

I remember watching a short documentation about an engineer from switzerland several months ago. But I was kinda half asleep and to my great shame I forgot to jot down the engineer`s name and project title. I tried to search about this topic on google, but I haven´t had any success yet, and dropped the idea for I could not afford to buy such a device anyway. The thing he invented and/or experimented with:
The sun shines into a flexible tube. Inside the tube is a fluid which allows the light to be captured and it can then be transported over some distance. That way the engineer manages to bring light even into your cellar. Amazing in my opinion. I would want that! Would reduce bulb use in many areas in a great way I think. Because sunlight is best to work with. The next step would be to collect the sunlight and store it, and release it when needed. Hmm, utopia for now, but we never know what we gonna have in a few decades. :)

Timpa said...

Good post! Youre like a psychic Jim, first the post a bout the pochade boxes, and now this!
Although I got my light setup about a week ago. Just two fluorescent 4000 k tubes balanced with some incandescent lights seems to do a good job, but im on a budget (aren't we all?) Maybe some day ill get some fancy schmaltzy setup like yours!

Charley Parker said...

Nice topic, thanks - and nice set up with the lined skylight!

Giving you the benefit of a future post of my own: though I'm normally skeptical of manufacturers who make claims for "daylight spectrum" bulbs; after doing my usual extensive research, I bought and have been very pleased with a Solux lamp; that is, according to the manufacturer and some other sources, the closest to a real daylight spectrum, without the unnatural spikes in certain areas of the spectrum characteristic of both incandescent and fluorescent sources (and also filtered to produce less UV and IR).

It's available from art suppliers like Dick Blick, but actually cheaper from the manufacturer. The floor model (about $130) comes with a table/shelf clamp as well.

The standard model comes with a 4700k bulb, which is supposed to be closest to daylight, but I opted for a 3500k after reading comments in discussion groups from several artists and photographers.

I have compared it to photographic floods, Ott Lights, other halogen and various combinations of incandescent and fluorescent, and it is the best painting (and art book reading) light I've ever encountered.

Katherine said...

Alandiras, I'm wondering if your man was talking about optical fibre tubes? ie using a bunch of mirrored fibres? I understand they can be 'fluid' (not sure how) as well as fibres.
Try here:
http://www.learn.londonmet.ac.uk/packages/clear/visual/buildings/options/core/index.html

Daroo said...

Great studio set up. I really like the skylight with diffusion screen idea. This might be a good solution for Florida artists because that far south, north light can't be relied on to be as consistent as it is in the north. Does the temperature in your skylight/reflector/diffusion box remain fairly consistent?

If one's goal is to match (approximate) their north light windows (so you can keep painting through the night) I think 5000K - 5500K is the proper temperature rating.

James Gurney said...

Charley, I look forward to your future post on lights. Thanks for mentioning Solux and Ott lights, which I forgot about. We have an Ott in the living room for reading art books, and it really brings out the color, but some of the bulbs are hard to replace.

Timpa and Daroo, I'm glad you mentioned the "K" rating, which I think is a measure of the color temperature of a black body heated to a certain temperature and giving off light--the higher the K, the cooler the light.

Katherine and Alandirus, I'm glad you mentioned those light tubes and gave links. I've seen them in use, and they help bring down light to a studio that's a ways down from the roof.

joverine said...

I'd love to see more of your studio! it looks soooo amazing! I currently work out of my bedroom-yes as a professional-but it's all I can do so far ;)
I love seeing artists workspaces!

especially when they're actually designed towards specific hand usage preference! ...ugh..words and me don't mix well :p

Emanuele Sangregorio said...

Hello Mr. Gurney! About this topic, I just read about this research, which is still ongoing, whose objective is to create a lamplight with the same spectrum of sunlight. pictures of the experiment look really promising.
http://ec.europa.eu/research/innovation-union/ic2014/index_en.cfm?pg=showcase12