Monday, February 13, 2012

Science light!


This is a shot of my easel showing the rack I have sticking out from its mast. Here is where I hang my lighting. When I built the studio I installed an outlet at nearly ceiling level, which is switched from beside my easel. I put in the outlet and the rack rather than a fixed set of lights because I wanted to be able to experiment and change my lighting from time to time. Usually I work only by natural light from my large north windows. However this time of year when the days are so short or when I am in vampire mode and staying up all night, I need to have science light!

There have been a lot of different combinations of fixtures hung from that sad, embarrassing flap above my easel! For a while I liked the idea of using the same kind of halogen track lighting that my galleries had. But I was unhappy with the way my color looked the next morning when I saw what I had done in the cool remorseless light of day.

When I have tried to paint under incandescent light or ordinary florescent tubes my color is way off too. Usually the pictures look dull or lean too far towards one color cast or another. I have never really worked too hard at achieving studio lighting for night painting, and I am too cheap to invest in fancy lighting for that. But last week I decided that I needed to get better light, as I have been working in my studio a lot at night lately.

With all of the people who read my writing I am sure that someone is a lighting engineer, and I know one guy on the Cape ( who often serves as the volunteer scientific adviser to this blog) who is a physicist or something. They all know lots more than I do and will probably weigh in on the scientific side here but I will summarize briefly what I know,with no equations. The people who deal with this for a living throw around formulas and equations that make my head hurt. I'm a high school drop out, I am hiding from mathematics.
  • daylight is about 5500 Kelvin ( a measurement of color temperature) That actually varies as the light from a north window is quite cool and morning light would be much warmer.
  • Most commonly available florescent tubes and also incandescent bulbs are far warmer than that .
  • Any bulb or tube can be labeled "daylight" and not be suitable for painting.
  • CRI ( color rendering index) is a measurement of how well one can judge color under a particular light. This is a real important number when buying your lights.
  • So when you shop for studio lighting you are going to have to go florescent and look for a temp of about 5500 Kelvin or somewhere near that. BUT very importantly, you will need to find bulbs that have a CRI of 90 or above.
  • Ordinary household florescents have a CRI as low as 70. That's why you look like a corpse under them. It's the lights, you don't really look that bad.
  • There are expensive "full spectrum bulbs that can be found online that will meet this test and claim to cure you of the "winter blues", (seasonal affective disorder) if you have that go see a doctor or an herbalist. These lights are no doubt very fine, but I am too cheap to buy them. They are called "full spectrum" bulbs because they produce all of the different colors of light needed to judge your color.

Home Depot ( or your local big box retailer) sells lots of different fluorescent tubes. Most of those are far from being acceptable in the studio. But a few are. I just picked up a couple of sets made by Philips that seem to work fine. A purist or a scientist might tell me that the expensive bulbs sold by Tubes R' US might be better, and perhaps they are, I don't know because as I mentioned before, I am too cheap to find out.

Since I last bought tubes the bulbs have wizened down to a thinner size so I picked up a set of those and a shop light nest to house them. They seem to be noticeably brighter than new tubes in the old style dimension. I now have four florescent tubes about three feet over my head as I work. The new style bulbs are 22 watts and the old style are 40 watts.

Either way, they seem to be fine so far and I can work under them at night and my paintings don't look radically different by daylight. Four bulbs and a two light fixture ( I had one fixture already in inventory) cost me under fifty bucks. That leaves me with money to spend on cigars and Moxie, and maybe I will have a candy lunch!

18 comments:

Michael Chesley Johnson said...

Isn't it interesting that lights with a higher temperature look cooler, while lights with a lower temperature look warmer. I think our caveman brains are wired to think: "Yellow fire - HOT! Blue ice - COLD!" So, we think of yellow light as warmer and blue light as cooler. When it's actually the reverse...but not for artists.

Sonya Johnson said...

Thanks for this. I'm stuck inside painting now because I'm a total sissy (I can thank a vasospastic condition for that) and can't paint outdoors when it's cold ("cold" = anything lower than 45 deg).

I have a fluorescent fixture and two thin bulbs in storage...must go check and see if they are the right kind and if I can jury-rig something up, since the recessed lights just aren't cutting it. Your set-up looks great.

Carol Reynolds said...

What a great set-up ! Also I envy your windows as well. Thank you for the great information on the proper bulbs.

Tim said...

If you have a printstudio nearby (proper one, not Kinkos) you can call/email them and ask them what they use to proofread colors under, they dont usually come better than that for CRI and closest daylight equivalent. These tubes are usually more expensive though (Specialist, eh? Well, then I think we can charge you triple!) sometimes ranging in the 15-20 bucks a tube area but you can be sure that when that shop does a 100.000 dollar print run of a catalog they use the right stuff.

DennyHollandStudio said...

This is an issue I've been struggling with the last few years as I prefer to paint sometimes late into the night, but my eyes are getting weary as I move into my 50th decade. Sometimes seeing the painting the next morning under natural light is a harsh reminder that my studio light need work. Thanks, Stape...

Daniel Mundy said...

Here's what I've come to regarding lighting. Paint under crappy light and very little of it. If your light is so much better than that of the gallery or your collector's environment then the paintings fall flat when not in the studio. Use a dimmer if you have to... I've even shuttered the windows during the day and looked at the work in very low light. Helps see the shape of the lights in the piece. One way to think about color temperature is that when you paint under cooler light you will work to keep the painting warmer, then when you do see it in natural light the piece won't look so icey cold. Great subject Stape!

robwood said...

I've worked in the lighting field for the last 4 years and it is still confusing me. Incandescent bulbs have CRI of 100, yet, as you point out, have a color temp too low to approximate daylight. Finding the right combination of CRI, color temperature and lumens at the work surface is more art than science. FWIW, as an amateur artist, I've also gravitated toward fluorescent tubes made by Philips, w/ a temp of 3500K. It seems to be important also to study your work in dim light as you go, it will help the color and light pop under ordinary lighting.

willek said...

This posting is going to trigger tons of comment, I bet. But not from me as I have made it a rule to not pay any attention to the light I am painting in. But I am very concerned about the light falling on the model or the objects in our painting groups. If the light falling on the artists easels in such a situation is pumped up, it often confuses and dilutes the strength of the shadows on the model. It makes me wonder what is the ideal taught in the ateliers.

Bruce Wood said...

I'm with Rob on the choice of Phillips 3500 Kelvin tubes... and keeping them not too close to the art.

Used to paint under halogen 3200K gallery floods, but they tend to be too bright and can give a "hot spot" in the center of whatever they shine on.

Unlike Stape, I find that paintings made in daylight fall flat when viewed in incandescent home lighting. So, keeping in mind that the final destination of my paintings will either be a gallery, a residence or a closet, the 3500K lighting is a compromise which helps the viewers see what was intended... at night... with the lights on.

Deb said...

What kind of candy?

RRoseman said...

I went to Home Depot yesterday morning and bought the Phillips lights to replace my dying florescent lights in my studio garage so reading this was funny timing-great minds......I usually have another Ott light that I use close to my work which helps me, too.

mariandioguardi.com said...

I have an array of lights and mixtures of cool, warm and daylight. But the final test for me is to bring the painting into one of my rooms with typical lighting to see what I can and cannot see. Yes, DanielMurphy, i also paint under as little lighting as I can get away with.

Stapelton, I know that you like to reproduce gallery lighting because that is where your painting is being sold from but I prefer to reproduce the typical home setting because that's where my paintings will eventually hang, in a home.

Here is a hint for Valentine's Day, everybody; buy an old diamond. Modern diamonds are cut to dazzle under diamond lights at the jeweler's. Old cuts (mine cuts included)like Rose cuts, were cut to dazzle under low light, candle light. They are incredibly beautiful in low lighting. And they are not expensive comparatively speaking..so now go out and buy her a vintage diamond and a box of chocolates and have a great Valentine's day and night!

billspaintingmn said...

I wonder what lighting Seago, Hibbard and Metcalf used?

Sure, if you're going to paint at night, you'll need more than a candle.
But I think lighting is only part of the equation. The frame should be considered as well.It makes a difference and it all has to work together.(my opinion)

You don't need to flood a picture to enjoy the passages.

Strong lighting can make a gold leaf frame look cheesy. A spot can help but best to take it easy.

lagoarthur said...
This comment has been removed by the author.
Lago Arthur Studio said...

Excellent post Stape! I work almost exclusively at night (except on weekends) because I still have a child not in school full time. Lighting is a huge issue for me! Thanks for pointing out some of the science behind the lighting. I'll be sure to pay closer attention to my bulbs from this day forward.

DGehman said...

A timely post indeed. A few hours after reading it, I hit the switch in my baseme... er, studio, and one of my painting-critical fluorescents had burned out.

So, after a quick trip to Lowe's, I now have two 5000 K 90 CRI GE Sunshines bearing down on my easel.

Perfect timing. And welcome advice.

Dale Cook said...

I just made the switch to the higher temp lights. I had switched two of the three bulbs and was shocked to see how yellow the remaining bulb was. I think this will make a big difference for me as most of my painting is done in the evening.

Thanks for the post.

Dagoelius said...

Hi Stapes. Not sure if someones mentioned it yet but you have looked into full spectrum lighting? Far better that fluoro for your eyes & sleep pattern health as well.
Not sure of best suppliers in the US but heres are some brands to show what I mean.


http://solux.finerimage.com.au/Solux-Daylight-Bulbs.php?C=Sx&AD=DL&K=[daylight+globes]

http://www.viva-lite.com/full-spectrum-lamps.html