Matching north light with fluorescent bulbs

[Richard Monro]

Marvin,

When I was setting up my new studio I researched lighting extensively. Hopefully the following will help. Color Rendering Index is very important as is the Kelvin temperature. Both must be considered together to get the best light compromise...and it is a compromise. North light is about 7500 Kelvin according to some sources and tends to be more blue and balanced in spectrum than south daylight. However, the reflected color from your studio walls and ceiling will influence the color you see. Hence my statement about chosing the best compromise.

Lumichrome flourescent bulbs at 6500 kevin and 98 CRI seem to be the best compromise of both criteria for bulbs on the market for the studio artist. Going with lights that are between 5000 and 7500 kevin and with a CRI greater than 92 should work well in any case.

If you want to get very technical you can do prismatic spectral analysis to verify that your new lighting reasonably matches your north light. In the end though it will come down to what pleases you as your art will ultimately be displayed in lighting that will be anything but north light.

Wish you success.

[Richard Monro]

Garth must have posted his reply as I was writing mine. Way to go Garth. Your diffraction grids show that there is a reasonable spread of light Kevins that can be chosen.

[Michele Rushworth]

Chris, thanks for posting that link for the screw-in 6500K bulbs. I have two light stands in my studio that I like to move around depending on what I'm doing and it would be great to have decent bulbs to put in them. I'll check out the TCP bulbs.

[Richard Monro]

Chris, I checked your link and could not find the 6500K bulb. What was the CRI for this bulb?

[Chris Saper]

http://www.1000bulbs.com/search.php

You'd have to ask them about the CRI

[Timothy C. Tyler]

And here's what happens. We paint under perfect lights. Then (some of us) send our works to galleries who place them under hot spots about 3800k. Then someone buys them and you have no control or idea of how they will be hung.

This was the long view when the CAA's began discussing this 10 years ago. Perfect circumstances are for perfect worlds. Compromise is the reality. As many of you know, the galleries may never even give you the name of the buyers. Selling directly to a portrait client, you can nudge them and try to educate them-but everyone won't listen.

The bulbs also change their temperatures as they age-just like in the tanning booths. But take heart, Sargent, Whistler, Monet, Titian, Zorn, Sorolla and Vermeer did okay without these.

[Allan Rahbek]

Originally Posted by Timothy C. Tyler

But take heart, Sargent, Whistler, Monet, Titian, Zorn, Sorolla and Vermeer did okay without these.

They all painted in the daylight, either indoor or out, right?

I have read that Da Vinci recommended painters to shade there studio windows with thin white linen to dim the light and even put an extra layer along the sides of the window to make the light extra soft. I came to think of this information some months ago when I had trouble seeing values because the light was too strong over my easel. I then changed the direction of the light to a reflection from the white wall and felt that it was much easier to judge the light values of the colors.

One thing that I have noted is that paintings with a good value scheme always show well no matter what light conditions they are seen under.

We could mark our paintings to inform the costumers about the optimal light to be seen in. Some of them might be interested I think.

Allan

[Timothy C. Tyler]

Despite all the tests etc the companies do, I desire to see more purples and blues in the shadows. I feel natural light does this better. Many modern painters work seems hot to me-I blame electric lights. These old artists had nicer cools. What do you think Bill and Michael?

When I paint outside on cloudy days the mids and cools are lovely. I'm designing my lights for my new studio and all this is most interesting.

[Elizabeth Schott]

I don't mean this to sound like an incredibly stupid question, but... on a very nice day does anyone just roll their easel and reference (not live models) outside?