Artificial lighting

Holly Snyder · 06-10-2004, 10:44 AM

Marvin,

I couldn't decide on which ones to get, so I got both. The 6500K are bluer and the 5000K are redder. I'm not sure which I like better, but I'm leaning towards the 5000K Originally I thought I'd only need two lights (one fixture), but then with the four lights I decided to use two fixtures. So far I've been painting with both fixtures on, basically mixing the light color. The extra light is wonderful.

I should get around to posting the spectrums of each using the diffraction grating method pretty soon.

Holly

Joan Breckwoldt · 06-26-2004, 10:33 AM

After another solid week of rain here in Houston I must do something about providing light in my 'studio'.

Holly and Garth, it looks like you're both using the same T-8 light fixtures from Home Depot (and one from Loew's for you Holly) but Garth, you mentioned your doesn't hum, but Holly, your light fixtures do.

The light tubes themselves wouldn't cause the humming, would they? As I understand it, it's the ballast in the fixture that may cause humming.

I don't listen to music when I paint, or anything else, so I would prefer to find a quiet set up.

Does anybody have an explanation as to why some light fixtures hum and some don't?

Thanks!

Joan

Sharon Knettell · 06-26-2004, 11:09 AM

Quote:

Originally Posted by Joan Breckwoldt

After another solid week of rain here in Houston I must do something about providing light in my 'studio'.

Holly and Garth, it looks like you're both using the same T-8 light fixtures from Home Depot (and one from Loew's for you Holly) but Garth, you mentioned your doesn't hum, but Holly, your light fixtures do.

The light tubes themselves wouldn't cause the humming, would they? As I understand it, it's the ballast in the fixture that may cause humming.

I don't listen to music when I paint, or anything else, so I would prefer to find a quiet set up.

Does anybody have an explanation as to why some light fixtures hum and some don't?

Thanks!

Joan

Joan,

My husband, an electrical engineer, has come up with an explanation and perhaps a remedy for your dilemma.

You were right about the ballast, aka, as the transformer being the problem. The bulbs do not hum as you so correctly observed. The transformer in the fixture is failing and depending in the kind of fixture you have, it may or may not have to be replaced. Sometimes a fixture will be equipped with a starter, a 3/4" silver cylinder at either end. If you can find that, remove it and take it with you to a hardware store to get the proper replacement as they often differ. If you cannot find a silver cylinder then you need a new fixture as the transformer is inside.

I hope that will help!

That puts to rest the myth that a partner should have equal interests! His scientific knowhow has bailed me out of many a pickle.

Joan Breckwoldt · 06-26-2004, 12:45 PM

Quote:

Originally Posted by Sharon Knettell

Sometimes a fixture will be equipped with a starter, a 3/4" silver cylinder at either end. If you can find that, remove it and take it with you to a hardware store to get the proper replacement as they often differ.

Thank you Sharon for your response. I haven't bought the light fixtures yet and I was just wondering (before I headed off to Home Depot) why some seem to hum and others don't. It sounds like a brand new fixture shouldn't hum and one that hums is defective in some way? Or, as you said, needs a replacement part becuase of age?

Thank you Garth, a slight hum is fine. Our computer is in my 'studio', which is really the studio/computer room, and I never even noticed the hum of the computer. I am not lucky enough to have a soft breeze outside the window, it's pounding rain and thunder lately.

I am sure my husband will not be excited about this next project, putting up lights! But, I will just have to remind him that this will (hopefully) further my career (i.e. get money for paintings!).

Thank you Sharon and Garth,

Joan

Holly Snyder · 06-29-2004, 12:15 PM

Hi Joan,

The hum is subtle, louder than other fluorescent fixtures in our house (which I can't hear at all), but quieter than the computer in my studio. It's constant, so my brain filters it out and it's certainly not loud enough to bother me. I don't know about bad ballasts, as both are new fixtures by different manufacturers, but both happen to have the same Sylvania ballast. If you're interested in the Lowes or Home Depot electronic fixtures, I would just try one and take it back if it bothers you. I would be curious what you find if you do buy one, however. You could also check if there's a specialty lighting store in your area, one in our area had just slightly more expensive electronic fixtures ~$35.

Good luck,

Holly

Joan Breckwoldt · 06-29-2004, 02:37 PM

Hi Holly,

Thank you for your reply. It sounds like the hum isn't bad at all. Right now I'm using a screw-in flourescent bulb in a regular fixture at it is amazing how much it helps! I'm using the same bulb that Chris Saper used to light one of her models that I admired. I took some photos of our babysitter this morning (just posted them) and I used this light to supplement the natural light.

Maybe, just maybe, I can get away with painting with this one fixture, in addition to the overhead light. My husband would be thrilled about that, especially after I showed him the shop light configuration I had in mind! I have four windows in this studio/computer room but again, the sky is dark grey outside. I guess I won't know until I start my next portrait. I'm painting a friends cat right now as a thank you and the lighting is not a big deal (compared to portraits). I hope to start the next portrait in a day or two.

thanks again,

Joan

Michele Rushworth · 06-29-2004, 03:03 PM

Quote:

I'm using the same bulb that Chris Saper used...

Can you tell us what kind of bulb that is?

ReNae Stueve · 07-11-2004, 07:42 PM

RE: Humming Ballasts. There are several types of Ballasts on the market, each designed to operate different lamps. If you have a fixture that takes F32T8 Lamps of any spec, you have a lamp that is 1" in diameter and designed to be pushed by an electronic ballast. This is the most current commercially used set up and should not produce any hum, but harmonic distortion is an issue, however not if you have a single 4 lamp fixture on the line.

The F34T12 RS lamps, at 1-1/2" diameter, are pushed by an electro-magnetic ballast, and these ballasts can make a nasty noise.

These are both called Rapid Start. Look for the RS on your lamp logo. No starter is needed. The starters are still used today in lamps 24" long and under, in any tube diameter.

The problem with the Home Depot style fixtures is that even though the ballasts and lamps are labeled GE or Sylvania, they are mass produced "B" quality for home use, typically garage lighting where hum and VCP, CRI are not an issue.

If you have a commercial electrical supply house in your area, ask if they have the GE UltraMax Ballast and SPX series lamps. This combination all but eliminates hum, distortion and the terrible eye fatigue you will get from residential brands because they have included a very effective Striation Control with this combination.

Try, Graybar.com or search Lithonia Lighting or Genlyte-Lightolier for store locator's.

Garth Herrick · 06-26-2004, 11:10 AM

Hi Joan,

I had to turn off my computer to listen for any signs of humming from my T-8 lights. To be honest, if I listen really carefully, there is a very very very very very slight hum, but I really can not hear it. It is quieter than the soft breeze blowing out my window, and many times quieter than my computer. I am sorry to hear Holly's lights do hum, but mine effectively don't.

Garth