Compact Fluorescent in a China Ball

[Craig Knowles]

I'm thinking about using a 150W compact fluorescent inside a china ball and I'm wondering if I will get any flicker at 24fps. Anyone else try this?

[Michael LaVoie]

You shouldn't get flicker problems from more recent CFL's unless you are using a high shutter speed. High frame rates may also cause flicker.

[Michael Nash]

No flicker at 24fps and 60Hz. power -- but they flicker like mad if you try to dim them!

 

Of course fluorescents also have a green spike, no matter what color tempertaure or CRI they claim.

[Richard Andrewski]

No flicker at 24fps and 60Hz. power -- but they flicker like mad if you try to dim them!

 

Of course fluorescents also have a green spike, no matter what color tempertaure or CRI they claim.

 

Only try to dim those bulbs that specifically say they can be dimmed. Others may be damaged by trying to dim them.

 

As for spike, that may be true but its mostly a problem for film use. Most people using digital media don't notice it. I've shot video with Home Depot N:Vision 3500K and 5500K bulbs at CRI 80 on a VX-2000 and never see green artifacts.

Edited February 26, 2007 by Richard Andrewski

[Richard Andrewski]

Also, for those interested in why there's a green spike I wrote an article recently in my blog about this "Green Spike or Why Do Fluorescent Lamps Have Mercury in Them":

 

http://www.coollights.biz/wordpress/archives/14

 

It's really not a such bad thing as digital medium are more foregiving than film and the more you try to balance the spike out the more you negate the energy efficient qualities of fluorescent.

 

Also, for those interested in the topic of CRI I wrote "Color Temperature and Color Rendering Index" which goes a bit deeper than most of the information available on the subject and actually talks about how you measure CRI showing the equipment used:

 

http://www.coollights.biz/wordpress/archives/13

[Walter Graff]

GE is notorious in the mercury department with some of their lamps such as the 22 inch u bent lamps, the same ones they label as "low mercury" actually contain upwards of 60mgs of mercury. Mercury content is not necessarily about size. Many of the GE 48 inch T12's contain upwards of 30mgs of mercury but a smaller GE 6 inch, 4 pin tube contains upwards of 30mgs of mercury too. Mercury is the second most deadly substance known to man so you never ever want to break one of these tubes deliberatly, especially if it is still warm or has been in the sun or near heat.

[Richard Andrewski]

GE is notorious in the mercury department with some of their lamps such as the 22 inch u bent lamps, the same ones they label as "low mercury" actually contain upwards of 60mgs of mercury. Mercury content is not necessarily about size. Many of the GE 48 inch T12's contain upwards of 30mgs of mercury but a smaller GE 6 inch, 4 pin tube contains upwards of 30mgs of mercury too. Mercury is the second most deadly substance known to man so you never ever want to break one of these tubes deliberatly, especially if it is still warm or has been in the sun or near heat.

 

That's true. I hate it in the past when I've ordered fluorescent tubes from someone and they arrive broken. My first thought is, okay should I call the Hazmat team to come clean everything here in the vicinity.

 

But all in all, it would be tough to have energy efficient lighting without mercury. Even HID bulbs like metal halide and HMI have mercury in them. The green spike is either something for a bulb manufacturer to balance out as much as they can or for us to filter out in some other way. For my part, I'll live with it because I hate the effects of hot lighting working in small spaces, the electricity bill that results from using them and the double whammy of the extra air conditioning necessary to displace the heat. Really makes making video more of a pleasure than it used to be.

Edited February 26, 2007 by Richard Andrewski

[Alexis Vanier]

I shot a slasher/thriller feature pilot using warm white CFLs in chinaballs for a couple scenes. We deliberately lit some scenes to get that green spike and that was fine. As for flickering, the bulbs we had exhibited none at the speeds we shot. Overall, I'd recommend to keep away from those unless you either know how to cope with green spike (although I haven't tested higher CRI bulbs) or want the green spike. Nevertheless, in chinaballs they're just wonderful. I stuffed a 24" lantern with four 1600 lumens CFLs (100w tungsten equivalent) while getting 2/3 the heat output of two 100w tungstens. My experience also showed me that CFLs individually cannot get hot enough to even yellow the paper if it gets in contact. It just made me feel safer... until the tubes started wiggling in their base.

 

But that's another story.

[Richard Andrewski]

Tubes wiggling in the base is a fairly common phenomenon. Were you shooting your pilot in film or digital? I assume film. Green spike isn't so difficult of a problem for those working in digital. It depends on a lot of things like whether they used the higher quality phosphors in making the fluorescent tubes, etc. The more you balance out the green spike, unfortunately, the more you negate the energy efficiency of those bulbs and need to crank them higher or get higher wattages. Higher CRI = less lumens. The green spike from the mercury is actually what makes the bulbs appear to be more bright to us.