About Kino Flo bulbs

[Mo Kamal]

I'm in the process of building a D.I.Y fluorescent kit, actually I have the ballasts, reflectors, and everything i need except for the bulbs.

 

Since I have no experience with all this stuff, I've been reading around and was about to order some Kino flo 55w bulbs, but I came across some posts where people mentioned that Kino bulbs would not work well with non Kino ballasts.

 

Anyone have any experience using Kino tubes with D.I.Y fixtures or using any non Kino Flo ballasts?

 

Any input would be really appreciated.

 

Thanks.

[Richard Andrewski]

Quite a few people have done DIY fixtures using non-Kino ballasts but with Kino bulbs. It works fine. Check over on DVXUser in the DIY forum. Someone built one recently and you can see it there clearly functioning with Fulham ballasts and Kino bulbs.

 

In general the 55w bulb is a pretty solid standard and as far as I've seen all the major ballast manufacturers: Advance, Fulham, Universal, etc. all stick to that standard as do the many manufacturers that make 55w bulbs.

[John Sprung]

I've heard that they may have problems in ordinary architectural fixtures, where they may run hot and output more green than they would with proper ventilation.

 

 

 

 

-- J.S.

[Jamie Metzger]

Be careful of flicker as well!

[Michael Collier]

I have heard (though I have no evidence to support it) that most likely if a kino bulb is not doing well in an archetexual fixture, its likely that the ballast is old. Green and flicker might be a result of an older ballast not supplying the propper voltage/frequency to drive the floros. I think in those cases it maybe likely that normal tubes would present with the same issues.

 

I would be interested to hear if this is true or not, and if anyone has any evidence of it.

[John Sprung]

Flourescent flicker comes in two flavors. First there's the gross, see it with your eyes kind of flicker. That comes from a tube or balast that's crapping out, and happens because the arc current varies wildly, or even drops out and re-strikes. However it looks to your eyes, it'll look at least that bad on film or tape.

 

The other is the beat frequency flicker you get from an incompatible combination of frame rate and power line frequency. The ballast of a conventional flourescent tube simply passes along the frequency it gets from the power company, and the tube outputs two light pulses per cycle. So, here in the 60 Hz USA, you get 120 light pulses per second. In the 50 Hz countries, it's 100 pulses per second. Divide your local number by an integer (1,2,3,4,5,6, etc) to get the safe frame rates.

 

(CFL's, with their little built-in electronics, work differently. They flicker at extremely high frequencies, and are usually no problem for normal speed photography, other than the green.)

 

Unwanted green is always present in flourescents. It comes from the way electrons jump up and down in orbit in the mercury atoms. Mercury is chosen because it outputs a very large amount of ultraviolet light, which is what the phosphors turn into visible light. But the next largest output is the nasty green spike at 546.1 nanometers.

 

Flourescents are designed to operate with the phosphors at saturation (maxed out). They produce a little more than the maximum amount of UV light that the phosphors can convert, so the output stays constant even if the input varies a little. Output goes up with temperature and pressure inside the lamp, which is why flourescents suck in cold weather. When they run hot, the mercury outputs more light in the same proportions at all of its spectral lines. The UV lines max out the phosphors, and we don't see the rest of the UV. The green, though, goes up relative to the visible light from the phosphors. Our eyes auto-adjust out the extra green, but film and silicon can't.

 

 

 

-- J.S.

[Mo Kamal]

Someone built one recently and you can see it there clearly functioning with Fulham ballasts and Kino bulbs.

 

I'm very happy to hear this, do you happen to have a link? there are quite a few threads about DIY Kinos on dvxuser

[Mo Kamal]

I've heard that they may have problems in ordinary architectural fixtures, where they may run hot and output more green than they would with proper ventilation.

 

-- J.S.

 

I'm not too worried about ventilation cuz everything here is ventilated and the ballasts and fixtures have been tested with cheap 55w tubes and ran for hours with no heat problems.

 

I was actually worried about the Kino Flo tubes needing specific input from Kino Ballasts in order to function as expected, someone was saying something along those lines in a post I saw a while back.

Edited September 12, 2008 by Mo Kamal

[Mo Kamal]

Be careful of flicker as well!

 

 

The Fullham ballasts i bought are like 20 bucks each, they power two 55 watt tubes or one bigger tube, they are absolutely silent, we tested them on video using every framerate on our HVX and there was no flicker.

[JD Hartman]

The ballast of a conventional flourescent tube simply passes along the frequency it gets from the power company, and the tube outputs two light pulses per cycle. So, here in the 60 Hz USA, you get 120 light pulses per second. In the 50 Hz countries, it's 100 pulses per second.

 

(CFL's, with their little built-in electronics, work differently. They flicker at extremely high frequencies, and are usually no problem for normal speed photography, other than the green.)

 

-- J.S.

 

If by "conventional", you mean a magnetic ballast, the majority of fixtures in modern buildings will have electronic ballasts, quiter, more energy efficient, better lighting quality. So re-lamping with a Kino or similar tube should be just fine.

[Richard Andrewski]

I'm very happy to hear this, do you happen to have a link? there are quite a few threads about DIY Kinos on dvxuser

 

Yes I've posted a few myself over there as I've built my fair share of stuff too. Here's the latest and this guy did an admirable job:

 

http://www.dvxuser.com/V6/showthread.php?t=145518

 

Given that a Fulham ballast (and most of the competitors these days too) drives its output voltage at 40,000 times per second frequency, you won't be seeing flicker. Its getting pretty darn hard to find a commercial electronic ballast that drives at a frequency less than that. Advance ballasts drive at about 25,000 per second and even that won't produce flicker at all. Universal, Osram, Sylvania are all great too--I've tested them all. As far as a market leader, Osram ballasts are the most commonly used ones in fluorescent studio and location fixtures-- far more than there are Kino ballasts out there. Osram tubes are also the most commonly seen tube too on all these fixtures. They all work fine, tons of studios like TV stations out there using them.

[Mo Kamal]

Yes I've posted a few myself over there as I've built my fair share of stuff too. Here's the latest and this guy did an admirable job:

 

http://www.dvxuser.com/V6/showthread.php?t=145518

 

Given that a Fulham ballast (and most of the competitors these days too) drives its output voltage at 40,000 times per second frequency, you won't be seeing flicker. Its getting pretty darn hard to find a commercial electronic ballast that drives at a frequency less than that. Advance ballasts drive at about 25,000 per second and even that won't produce flicker at all. Universal, Osram, Sylvania are all great too--I've tested them all. As far as a market leader, Osram ballasts are the most commonly used ones in fluorescent studio and location fixtures-- far more than there are Kino ballasts out there. Osram tubes are also the most commonly seen tube too on all these fixtures. They all work fine, tons of studios like TV stations out there using them.

 

 

wow, there really is a lot of DIY stuff going on, suddenly I feel like there are so many options and ways to go at it.

 

It's definitely gonna take me sometime to read all this stuff before I know what I want to do next.

 

Thank you for the pointers. :)

[J. Søren Viuf]

Is there a way to achieve said "gross" flicker? A way to cheat it even?

[Dan Goulder]

Don't overlook the newest generation of "swirly" flourescents. They're designed to work in a standard light socket, and they've become more powerful. As for color temperature, they don't tend to hit the 5500 degree standard. However, color-wise, they do match well with indirect daylight, which tends to fall off in temperature the farther back from windows that you go.

[Guest Evan Pierre]

Don't overlook the newest generation of "swirly" flourescents. They're designed to work in a standard light socket, and they've become more powerful. As for color temperature, they don't tend to hit the 5500 degree standard. However, color-wise, they do match well with indirect daylight, which tends to fall off in temperature the farther back from windows that you go.

 

And if you put them on any sort of dimmer they flicker like mad! Really awesome if that is an effect you want to achieve. :lol:

[Adrian Sierkowski]

Do they really. . . hmmm. . .I might need to try that. . . for effect!

Evan et al; color wise anyone know the best CRI swirly ?

[Steve London]

Do they really. . . hmmm. . .I might need to try that. . . for effect!

Evan et al; color wise anyone know the best CRI swirly ?

Check out n:vision

[John Brawley]

I've heard that they may have problems in ordinary architectural fixtures, where they may run hot and output more green than they would with proper ventilation.

 

 

 

 

-- J.S.

 

 

I believe the issues is that actual KINO ballasts OVERDRIVE the tube and run it very hard, thus greatly shortening it's operating life. They do this to get a higher output so the tube fixture is brighter. So KINO tubes are designed to be driven HARD so the colour output is optimised for KINO ballasts. When used in conventional ballasts they turn to do funky things. You might as well use regular tubes.

 

jb

[Paris Remillard]

This is a bit off topic since the original question was about bulbs, but make sure that you test the ballasts that you plan on using at all shutter speeds and frame rates. I've been adapting Linear T5HO Grow lights and High-Bay Warehouse lights for film/photo use, and most of the high frequency electronic ballasts, including the Fulhams mentioned here and on DVXuser, have issues at higher frame rates and shutter speeds. Of the ballasts that I have, at 1/250th sec and above, the only ballasts that didn't cause sort of rolling color phase shifts were Advance Powerline Mark 10 dimming ballasts, which actually operate at 42kHz or above according to their literature. Not 25kHz as was mentioned. The fulham workhorse 5, A generic chinese brand, one which is sealed in a small single bulb fixture so I can't see the brand, and a Sunpark SL15 electronic T8 ballast all produced the same results.

 

On a DVX at 1/250th sec and above, the color shifts slowly from the normal color temp set in camera, to cyan, to very green, then back to normal. The shifts are faster or slower depending on the shutter speed. It can be very slow and subtle and hard to see if you don't watch for it. At 1/250th and above on a Red One, I get the banding or rolling bars caused by ballast flicker combined with the CMOS rolling shutter artifacts. Again it is usually a very slow change in color phase, it just slowly rolls on the Red as opposed to simply slowly changing color on the DVX.

 

I haven't tested any Kino Flos, or other production motion picture fixtures yet at the same shutter speeds. I did just get some Sylvania Quicktronics and some other Advance ballasts to test and compare. Anyway, I'd just suggest doing your own tests to make sure that things work the way you want them to. Ballasts being electronic and high frequency doesn't necessarily mean that there won't be issues.