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Dimming a Kino


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#1 Paul Salmons

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Posted 22 April 2013 - 10:16 PM

Hello, I was curious about the effects of putting a dimmer on a kino. Is it bad for the globe or the ballast? I don't mind burning globes and even though the ballast are rentals I don't think it's cool to burn them out. If it is bad for either can anyone give me some insight as to how bad? Will the globe only last for five minutes or just shorten it's life? Will the ballast immediately burn out? Any info is greatly appreciated! 

 

EDIT: I want the flicker effect as I am shooting a broken down space ship.


Edited by Paul Salmons, 22 April 2013 - 10:17 PM.

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#2 Phil Rhodes

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Posted 23 April 2013 - 12:05 AM

Putting any sort of dimmer on a kino ballast (and I assume you're talking about triac dimmers) will not give the results you're looking for. Electronic ballasts such as those used on kinos don't react the same way to a reduction in input power the same way old-style iron ballasts do.

 

You can run kino tubes off an iron ballast, with a switch starter, in which case they will flicker if you dim them. Even in that situation, though, you need to be careful as some triac dimmers don't like dimming anything other than tungsten lights and may be damaged.

 

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#3 Oliver Hadlow Martin

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Posted 23 April 2013 - 06:22 AM

A lot of kino flows have dimming ballasts but they go towards Magenta when you dim them. 


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#4 Paul Salmons

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Posted 23 April 2013 - 10:39 AM

Putting any sort of dimmer on a kino ballast (and I assume you're talking about triac dimmers) will not give the results you're looking for. Electronic ballasts such as those used on kinos don't react the same way to a reduction in input power the same way old-style iron ballasts do.

 

You can run kino tubes off an iron ballast, with a switch starter, in which case they will flicker if you dim them. Even in that situation, though, you need to be careful as some triac dimmers don't like dimming anything other than tungsten lights and may be damaged.

 

P

 

Thanks Phil, this is very helpful. I'm going to look into getting some iron ballasts (maybe start at home depot?) and try to get this working!

 

 

 

A lot of kino flows have dimming ballasts but they go towards Magenta when you dim them. 

 

Thanks Oliver! I'm not trying to slow the florescent down as much as get the light to flicker as if it was a poorly maintained light.

 

Maybe is there a way I can damage a globe just enough to get that effect? Shake it up just enough or somehow break some of the inner filaments? 


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#5 Adrian Sierkowski

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Posted 23 April 2013 - 10:45 AM

Why not save the kino tubes and just look into getting some typical floro home-depot tubes.....

 

also there are no filaments within a florescent light-- it's a plasma, technically gas discharge. There is a cathode at the ends, but I don't see shaking it enough to be  reliably way to damage that to the right amount.


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#6 Paul Salmons

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Posted 23 April 2013 - 11:10 AM

Why not save the kino tubes and just look into getting some typical floro home-depot tubes.....

 

also there are no filaments within a florescent light-- it's a plasma, technically gas discharge. There is a cathode at the ends, but I don't see shaking it enough to be  reliably way to damage that to the right amount.

 

Thanks Adrian! I'm thinking I am going to just build my own rig from the bottom up and see if I can make it work. Thinking I will start with this ballast or something similar. I have also been checking out some halloween forums and there is another way to make this happen with something called a flashing disc. Figure since I have a handful of dimmers I will start with building the ballasts and see if I can do it without the discs.

 

http://www.homedepot...-N#.UXasDb8Zfrp


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#7 Adrian Sierkowski

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Posted 23 April 2013 - 11:13 AM

Home Depot, at least awhile ago, was selling T12 fixtures for 2 tubes for $9.99 pre-built. I bought a few awhile ago to rig into a location because they came with a reasonable length of zip line. The looked horrible, as I wanted them too- but easier than building totally from scratch and good enough to test it on a dimmer right quick.


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#8 Adrian Sierkowski

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Posted 23 April 2013 - 11:14 AM

Looks like price went up a bit:

 

http://www.homedepot...77#.UXazT4IqmWE


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#9 Paul Salmons

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Posted 23 April 2013 - 11:24 AM

And this is why I love this forum. You just saved me a huge project and time! Thanks so much!


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#10 Phil Rhodes

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Posted 23 April 2013 - 11:40 AM

If you break the heater filaments in a fluorescent tube, it'll simply stop working. This is the most common failure mode for fluorescent tubes, as eventually the heater material gets evaporated off onto the inside of the tube, and the wire breaks (that's the black ring you get around the end of the tube once it's been in use a while).

 

If you want to forego the dimmer, you can wire fluorescent tube starters in series with some kinds of load (such as a reasonably low-wattage incandescent lamp) and get a constant flickering effect. You may still want to use a dimmer as it can be more controllable, and wire a constantly-illuminated lamp into the circuit as well to give triac dimmers something to work with.

 

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#11 Paul Salmons

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Posted 24 April 2013 - 11:22 AM

Hey guys just wanted to update on the progress. I went ahead and got the T12 florescent from home depot yesterday. It was cheap and worked great, the ballast on them is so bad they already have some built in flicker to my eye! I tried tapping in a 650 into the circuit and it gave me exactly the look i was going for. I'll wrap those bulbs in a little ND and I should have the perfect effect. Thanks again for all the help guys!


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#12 Adrian Sierkowski

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Posted 24 April 2013 - 12:02 PM

Glad we could help.


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