favorite t12 48" full spectrum tubes?

[yuandrew]

Re: favorite t12 48\" full spectrum tubes?

I'm using a GE Sunshine (Actually a Chroma 50) tube for general lighting in my bedroom. It's a 24" flourescent tube but when placed in the right spot on the ceiling, it lights up the entire room. I used to have to turn on 2 lamps with 100watt incadescent bulbs in it to get enough light before I mounted my flourescent lamp.
Anyway, in my opinion, the light from this tube seems to be white with some light blue tint. It is also hard to tell the difference when the light is on during an overcast day as the color temperture of sunlight is very similar.
I've considered using other brands of full spectrum tubes like OTT-LITE but haven't found a good place to purchase them yet.
As for the fixture, it's an old plastic 24" undercabinet light that originally had a magnetic pre-heat ballast and a built in starter. Recently, I hacksawed a cheap chinese-made 20watt CFL and removed the electronic ballast circuit board to put in the fixture. I actually noticed slight increase in light output after I did this mod and of course, it doesen't flash a few times before comming on anymore like it did with the old starter. Just instant on.

 

[snakebite]

Re: favorite t12 48\" full spectrum tubes?

i have been told that boas and pythons dont need uvb.
but when i installed reptile tubes that give low level uvb i noticed my boas would stretch out under it and get as close as they can.
i switched it to a standard cool white and i never see them get under it.
i put the reptile tubes back and almost immediatly they were under it again.
not sure if they need uvb but they seem to like it.

 

[jtr1962]

Re: favorite t12 48\" full spectrum tubes?

[ QUOTE ]
yuandrew said:
I'm using a GE Sunshine (Actually a Chroma 50) tube for general lighting in my bedroom. It's a 24" flourescent tube but when placed in the right spot on the ceiling, it lights up the entire room. I used to have to turn on 2 lamps with 100watt incadescent bulbs in it to get enough light before I mounted my flourescent lamp.


[/ QUOTE ]
This is interesting in that it shows that lamp placement and color temperature is as important as lumens. Two 100 watt bulbs put out about 3400 lumens total not accounting for any light absorbed by shades or diffusers. One 20W Chroma50 tube is rated at 875 lumens but since it's probably overdriven on the electronic ballast let's say it puts out 1100 lumens. Still a discrepancy of 3:1 but a light on the ceiling puts most of it's light directly to the area below while table lamps rely quite a bit on light reflected from walls or ceilings. Second, lumen for lumen a higher color temperature light has a higher apparent brightness. Indeed, a 1000 lumen 5000K light source appears as bright as a 1500 or 1600 lumen 2700K light source (typical for a light bulb). This is why it makes sense (to me anyway) that your room seems as bright with a single overdriven 20W as it does with 2 100 watt incandescent bulbs.

Yes, the chroma50's have a slight blue tint to them but blend in almost perfectly with daylight. I also prefer high color temperature lighting for all my general lighting needs, even in areas where it isn't traditionally used, such as bedrooms and living rooms. As my eyeballs are calibrated for sunlight, it only makes sense that artificial lighting should be as close to sunlight as possible. However, I do prefer higher lighting levels than a 20W tube. My bedroom's main light source is a 4X32W T-8 fixture putting out about 10,000 lumens. I use Paralite Maxum 5000 tubes (CCT=5000K, CRI=91). I also have two 28W 5000K CFLs for when I desire lower lighting levels.

As an aside, I think it's pointless to run expensive full-spectrum tubes on magnetic ballasts due to the annoying 60Hz flicker. However, on flicker-free electronic ballasts the tubes come very close to duplicating natural sunlight.

 

[nitebrite]

Re: favorite t12 48\" full spectrum tubes?

just an update on all the tubes i have tried. i have found that the expensive very high cri tubes are at either very low or very high kelvin temps. therefore my overall favorite is genuine ge chroma-50. very good representation for daylight. great for s.a.d. maybe not the very best color representation, but the best natural light representation at noon. keep in mind that the sun does not render colors as good as some of these tubes claim to. so actually they are unatural and artificial looking. for the kitchen i like, what else! ge kitchen and bath. these have very low cri since they are specificaly designed to exagerate reds and yellows. they do not flood the room with a yellow tint as many expensive reptile tubes that i can't stand do. they do however ecentuate the colors and make my 2-bit kitchen seem like one in better homes and gardens!
as for reptile bulbs i just love the ge frsesh AND saltwater aquarays. the freshwater only tube is not nearly as good as the combo one. again these have very low cri as they totally hype the blue spectrum. keep in mind that are beloved sf led's are completely blue and we drool over how white they are. so this bulb is awesome for animals and fish. the very expensive reptile tubes(i tried all of them) tend to all hype the yellow or red spectrum and claim to have 98 cri. hyping the blue imho in a animal cage is way nicer i think. also i have found that magnetic and starter tube ballasts provide much warmer color tone then t8 electronics i have. the electronic ones seem to add noise and flicker super fast. i have heard this is only noticable to like 1% of the population. i can see it and prefer old fashioned ballasts even though they may be harsher on bulb life. may favorite ballast? ge!

ok, this is not spam. i swear i have no financial intrest in ge. it just so happens that imho ge has some incredible lighting products on the market. i am NOT pushing ge on anyone. i am merely conveying my personal preferance.
i hope this imformation is helpfull to someone since i spent over $140 on testers to come to this conclusion. with no compensation, nor did i ask for any. it just so happens that it is all ge lighting that impressed me. trust me if it was sylvania or philips or whatever i would have said so. of course ymmv.

edit: i just noticed most of your sentiments about ballasts were the exact oposite of mine. i.e. electonicsa are warmer, and do not flicker as opposed to magnetics. just goes to show like i said ymmv. i think it just boils down to personal preferance. however i have noticed that the very high cri bulbs which are usually at high kelvin or low kelvin as opposed to 5000k are actually very unatural. we all seem to agree that the c50's are very close to daylight and only 90-92 cri depending on what literature you happen to be reading. hmm....


nitebrite.

 

[brickbat]

Re: favorite t12 48\" full spectrum tubes?

Isn't the term "full spectrum" just a bit of marketing hype? What, exactly does it really mean? Manufacturers might have us guess that it implied a continuous spectrum, with energy throughout the visible range, but the spectral power distribution (SPD) of ANY fluorescent I've looked at it quite discontinuous and spikey - nothing at all like the relatively smooth blackbody SPD of the sun, or, for that matter an incandescent lamp. Some might argue that it means that the lamp has a CCT similar to sunlight, but at what time of day? The hours around sunrise and sunset provide sunlight with a CCT of less than 3000K.

I guess the point I'm trying to make is that even the best "full spectrum" lamps have SPDs that look nothing like natural daylight. If you compare numbers, sure, the CRI and CCT can make the lamp look like it's really close to daylight, but (call me skeptical) I'm not convinced.

 

[Bob Snow]

Mixing different tubes

An old trick for using cheap fluorescent tubes was to mix cool white and warm white in equal numbers. The combination of horrid greenish cast and sickening pink was far superior to either on it's own.

 

[gwbaltzell]

Re: Mixing different tubes

I still mix deluxe cool and warm if I can't find good tubes in the right wattage.

 

[brickbat]

Re: Mixing different tubes

Sure, if a 4100K cool white is too blue, and a 3000K warm white is too pink, you can blend them, but the resulting spectrum still suffers from the spikes and valleys that the individual tubes had. The basic problem is that fluorescent tube designers only have a very limited 'pallette' of phosphor colors from which to choose. It's the physics of flourescence that dictate the emitted wavelengths, and there are only a limited number of chemicals that are suitable. The various color temps are just slightly different blends of the same phosphors. It may be a little counter-intuitive, but I think the best way to get a true full spectrum that approximates sunlight is to use an incandescent with a blueish filter to remove some excess orange light. (Of course the efficacy will be pretty poor...)