Overdriving lights etc

[BCOrchidGuy]

Does overdriving a fluorescent tube change the colour spectrum? I know that people OD the Radium bulb (HPS I think) with a Murcury Vapour (again I think) ballast and it changes the spectrum. If I remember right the Radium bulb is rated at 360 watts and it's a 430 watt ballast that is used on marine aquariums to make the light whiter or less blue.
What I'm thinking or asking is, if I use a workhorse ballast and run two 40watt NO fluorescents at 60 watts (1 actinic and one daylight) will there be a shift in spectrum?? If so does that occur as well with the Ice Caps when they underdrive the VHOs?
Will using a tar ballast give me different results?

Doug

[Invigor]

i tried overdriving t8 6500k bulbs to vho levels, and they "appeared" to me to be whiter..could just be because they were brighter, but they "appeared" to burn whiter.

[Rikko]

I'm sure Steve will jump in here before long, but IMO it can't change the spectrum. The spectrum of the bulb is determined by the coating inside the bulb - the invisible UV produced inside the bulb is "transformed" when it collides with whatever composition sits on the inside surface of the bulb. If a bulb is bring driven harder, there should just be "more" light colliding with the bulb coating, but no real change in its physical properties.

[marie]

I'm overdriving the GE ultra daylight bulbs and phillips actinics. What i have noticed is that the daylight bulbs seem to be overdriven more then the actinics are. When the bulbs were NO the colour was a lot bluer, now it's almost greenish

[BCOrchidGuy]

Thanks for the replies folks,

Marie, my understanding is that green would be a lower spectrum than blue so I'd assume your tube is either old or having issues. As spectrum increases light should go from Red, to Orange to Yellow, to Green to Blue to Indigo to Ultraviolet. That being said maybe the extra current is altering the way the phosphours react. I assume that you're using a tri phosphour so maybe the one phosphour likes the increase in current more than the other two or maybe two like it more than the other one. I assume the phosphours are all primary colours IE Red, Yellow and Blue.

Rikko, in a fluorescent tube the phosphours ( and possibly gas?) are excited by the electrical current (I believe). See if I'm completely flaking out here but, if the voltage is constant IE 120 (117) then the current (amperage) would go up (?????) so is it just intensity that goes up? If that's the case then great but if the colour actually changes that may be bad (maybe good though too). Ideally I could use a daylight deluxe tube (5500k) and over drive it to say 7500k or even better and then use the actinic blue and maybe have a decent appearance.

I understand that Metal Halides would just burn brighter and brighter until they burned out if we didn't have a ballast that limited the power consumption but do fluorescents do that as well? Can you overdrive or underdrive fluorescents on a tar ballast or is it only possible with an electronic ballast.

Doug

[marie]

I just assumed the daylight bulbs are burning brighter then the actinics when overdriven . I replaced the NO actinics with VHO actinics and all is right again

[Invigor]

i tried using 2 tar ballasts to drive 1 bulb and I popped the breaker

the only thing I found with overdriving is you completely kill the lifespan of the bulb. however, for a $5 bulb to last 3 months versus a $40 to last 12..it's still kinda worth it. I found the CRI to be crummy in the $5 bulb compared to the $40 VHO bulb though..the colors in my corals and fish were bland, whereas the VHO bulbs made the colors amazing. that is when I gave up trying to cheap out on bulbs.

[StirCrazy]

Originally Posted by BCOrchidGuy

As spectrum increases light should go from Red, to Orange to Yellow, to Green to Blue to Indigo to Ultraviolet.

Doug

change your "increases" to Decreases and get rid of the indigo and say Violet and your bang on. (real men should never use the word indigo)

no a fluorescent tube will not change spectrum but it will apear lighter because of the increase in intensity.

Steve

[Aquattro]

Originally Posted by StirCrazy

(real men should never use the word indigo

What's wrong with Indigo? I have a dish that color that I make my quiche in!

[BCOrchidGuy]

Okay so maybe I should have been born blonde (no offence to the blondes here). As temperature goes up (the carbon block thingy) I understood the colour went from red to orange etc etc etc.. all the way to denim and then ultra violet.. (is that okay?)
So, in theory if I went with a whitish NO tube for marine tanks and an actinic and had both over driven I'd be okay?? Or would I be better to say run a VHO actinic and a VHO 10,000k with a tar VHO ballast. The WH7 will run them if I'm not mistaken but at about 60 watts each... or did I just have to much beer at the burlesque show?

Doug