Artificial lighting

[Joan Breckwoldt]

Hi Michael,

Thank you for your information. I was hoping to avoid having some kind of set up which required the long tubes. It may come to that though, I'm not sure there is a screw in bulb (I mean the kind that screws into a normal light fixture) that will fit my needs. I do have a couple of screw-in bulbs that are flourescent and they help tremendously. Here in Houston we can get a week of overcast/rainy weather and it's tough to paint if I wait for sunlight!

Thank you again, I'll print out this info and add it to my other lighting info for when I do have to set up a 'bank' of light.

Joan

[Chuck Yokota]

I've been using GE Reveal screw-in bulbs. They are better than ordinary household bulbs for showing colors, and don't cost very much more. I don't know how they compare to the full-spectrum tubes.

[Mike Dodson]

Joan,

Although I use the 48" fluorescent tubes, I have also used these from Verilux and they work great :http://www.avitec.com/avihealthN.html

[Joan Breckwoldt]

Hi Mike,

Thank you for your reply. I have a bulb that looks like that but made my Commercial Electric, I got it at Home Depot. It's a flourescent. Do you know what Kelvin rating yours has?

Joan

[Joan Breckwoldt]

I just checked that website, say's that bulb is rated at 5500 Kelvin. Hmm, I think mine might be higher.

Okay, here's a question. Does all flourescent light put out the same temperature light? It seems like it would.

Joan

[Michael Georges]

Originally Posted by Joan Breckwoldt

I just checked that website, say's that bulb is rated at 5500 Kelvin. Hmm, I think mine might be higher.

Okay, here's a question. Does all flourescent light put out the same temperature light? It seems like it would.

Joan

I don't believe so. Your standard commercial flourescent bulb is between 3000 and 4000 K with a CRI somewhere between 50 and 80. They are much more yellow-shifted.

[Joan Breckwoldt]

Well Michael, that explains a lot, if what I got from Home Depot falls under 'standard commercial bulb'. But, how can it be that one flourescent bulb puts out 5500K and another 3000K? I don't understand that.

Joan

[Joan Breckwoldt]

I found a website that gave me some information on flourescent lamps. I have copied some of the info below:

Fluorescent Phosphors The color of fluorescent lamps is created by mineral phosphors in powder form which coat the inside of the lamp tube. The chemical make-up of these phosphors determines the lamps CRI, its Color Temperature, and how much light the lamp produces. There are four types of phosphor coatings:

Traditional halophosphors Are inexpensive coatings which usually provide the entire spectrum of light. But, there is a trade-off between Color Rendering and Lumen output. Poor color rendering lamps such as "warm white" and "cool white" have high Lumen output. Good color rendering lamps such as "warm white deluxe" and "cool white deluxe" have low Lumen output.

Prime color or Tri-phosphors Are very expensive coatings with good color rendering and high lumen output. Lamps of this type are produced under the trademark, Ultralume.

Double-coat lamps Have a coat of halo-phosphor and a coat of tri-phosphor. Double-coat lamps which have a thick tri-phosphor coat are fairly expensive but have very good color rendering properties. They are known by the trademarks SPX, Designer 800 series, etc.. Double-coat lamps with a thin tri-phosphor coat are much less expensive, but still have full light output and reasonably good color rendering. These lamps are known by the trademarks SP, SPEC, Designer, and others.

Rare Earth Phosphors Have a thin and thick coat of rare earth phosphors and are just becoming available. The CRI for these lamps will be 70, 80, and 90 and in a variety of Color Temperatures.

Whew, that's more than I wanted to know but at least it convinces me that all "flourescent" lamps are not equal.

The bulb I'm using doesn't have any info about it's temperature and their website had a range, just like you said Michael. So, I guess the best way is experimentation and maybe try that Verilux bulb.

Joan

P.S. This is where I found the above info:http://www.lightcalc.com/glossary.html