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New breed of flourescents?


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#1 Sean McHenry

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Posted 24 May 2007 - 12:20 AM

Hello everyone. I will be shooting a short on Super 8 soon and am wondering about a new fluorescent lamp I saw tonight at the hardware store. I saw a "Full Spectrum" tube like the type used in Videscense units or the type meant to replace a regular household lamp bulb. The 23 watt power consumption version puts out slightly greater than a 100W equivalent tungsten lamp. It says they are rated at 5000K.

I was thinking that since I need something a bit directional but soft at around 650 type levels for the shoot, I could easily mount 6 porcelain fixtures to an aluminum frame and put a separate switch on each tube. That would be a variable 100W to 600W unit at 5000K full spectrum. My question is, I'll be shooting at 24fps on a Canon 814XL-S and my jeep with a large 12v inverter would be supplying the power as we will be out in the middle of nowhere.

What sort of flicker am I setting myself up for, if any, and how full spectrum are these lamps really? This sure seems like a great idea for the $7.50 for each 100W tube.

I've searched the forums and found mention of these units at a crazy $69 each:
http://www.serviceli...fm?prod=MX35871

I can't find a link to these new GE CFL units yet but they were on the shelf at the local Lowes.

Other GE CFL (Compact Fluorescent Lamp) literature is here:
http://www.gelightin..._sheets/cfl.htm

I also found these searching for full spectrum lights. Note the price of the 42W (Replaces 200W Incandescent) 5 of these would be a soft 1KW for the cheap price of $90 in lamps at $18 each in 1-5 units. Variable in 200W steps.
http://www.fullspect...cent_32_ctg.htm

Thanks for any advice folks,

Sean
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#2 Richard Andrewski

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Posted 24 May 2007 - 12:59 AM

Hello everyone. I will be shooting a short on Super 8 soon and am wondering about a new fluorescent lamp I saw tonight at the hardware store. I saw a "Full Spectrum" tube like the type used in Videscense units or the type meant to replace a regular household lamp bulb. The 23 watt power consumption version puts out slightly greater than a 100W equivalent tungsten lamp. It says they are rated at 5000K.

I was thinking that since I need something a bit directional but soft at around 650 type levels for the shoot, I could easily mount 6 porcelain fixtures to an aluminum frame and put a separate switch on each tube. That would be a variable 100W to 600W unit at 5000K full spectrum. My question is, I'll be shooting at 24fps on a Canon 814XL-S and my jeep with a large 12v inverter would be supplying the power as we will be out in the middle of nowhere.

What sort of flicker am I setting myself up for, if any, and how full spectrum are these lamps really? This sure seems like a great idea for the $7.50 for each 100W tube.

I've searched the forums and found mention of these units at a crazy $69 each:
http://www.serviceli...fm?prod=MX35871

I can't find a link to these new GE CFL units yet but they were on the shelf at the local Lowes.

Other GE CFL (Compact Fluorescent Lamp) literature is here:
http://www.gelightin..._sheets/cfl.htm

I also found these searching for full spectrum lights. Note the price of the 42W (Replaces 200W Incandescent) 5 of these would be a soft 1KW for the cheap price of $90 in lamps at $18 each in 1-5 units. Variable in 200W steps.
http://www.fullspect...cent_32_ctg.htm

Thanks for any advice folks,

Sean


"Full spectrum" just means daylight simulation or something in the range of 5000K to 6500K normally but 5500K is the most common. It's used a lot in depression therapy for "SAD" so these bulbs can be found quite a bit more commonly now. They are all self-ballasted and usually have a ballast that's not as good or efficient as one you can get in a full blown pro-level flo light fixture (power factor is lower therefore they never really reach their theoretical output as well) but they usually don't flicker unless its a really cheap and crappy bulb.

The 200w bulb from Service Lighting is the one I've been advocating people use with a mogul-based fixture in a softbox for a "cool" alternative to tungsten softbox lights. Its the least expensive one I've found that is in the daylight range and is a very good quality lamp:

http://www.coollight...xture-p-33.html

Your link didn't work or was defunct, this is the actual 5000K 200w 8U bulb product CRI 85:

http://www.serviceli...fm?prod=MX35871

Here's another one that's actually 5500K but the price is a bit higher and so is the CRI though at 90:

http://www.teksupply...s...5054&isDoc=


As for the other, smaller bulbs (30w to 40w), I've also been telling people using DV cameras that there's no problem with these daylight CFLs from Home Depot or Lowes. These are in the range of 80 CRI and okay for non-critical applications. There's plenty of others that talk about it on other sites too and you can see videos people have posted that look just fine. The only thing is, you're using film so it may very well be more sensitive to the green spike than DV. If you try it I would love to hear how it comes out. To be safe, I suspect CRI of around 90 or above would be best for actual film use. CRI 90 and above bulbs are more expensive though because the phosphor used is more rare.

The fixture you mentioned building is being put together quite commonly now and you can even buy fixtures like that too with a collection of edison sockets in them.

Edited by Richard Andrewski, 24 May 2007 - 01:02 AM.

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#3 Sean McHenry

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Posted 24 May 2007 - 02:04 AM

Thanks Richard. Sounds like I really should shoot a roll of Tri-X and maybe test it with the Pro-8 250D too. Not sure what we'll shoot on but I'm leaning toward the Tri-X still.

Flicker at 24fps therefore was the big issue on this question. Oddly, I just finished bookmarking your site to read over in the morning.

I have had great success with a worklight and dual 5000K tubes. I think it compares to a 100W output in tungsten. Looked decent on DVCam with the little DSR PDX-10. I knew that light would come in handy.

Thanks for the info. I'll be checking the site in the morning. Retention will be better then I hope.

Sean
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#4 Richard Andrewski

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Posted 25 May 2007 - 07:43 AM

Thanks Richard. Sounds like I really should shoot a roll of Tri-X and maybe test it with the Pro-8 250D too. Not sure what we'll shoot on but I'm leaning toward the Tri-X still.

Flicker at 24fps therefore was the big issue on this question. Oddly, I just finished bookmarking your site to read over in the morning.

I have had great success with a worklight and dual 5000K tubes. I think it compares to a 100W output in tungsten. Looked decent on DVCam with the little DSR PDX-10. I knew that light would come in handy.

Thanks for the info. I'll be checking the site in the morning. Retention will be better then I hope.

Sean


That's great. I would love to hear how this comes out. We've had several people around the web, me included, who show that CRI is not as important as its always made out to be for video work. Next what we need is a good test showing what the real CRI requirements are for film. As far as flicker goes, I think you'll probably find that most of the ballasts on the ones I've been recommending to people are pretty high frequency output. The ballasts in my pro-level 55w fixtures are all running at an output frequency of 40KHZ. At that point, you would have to be shooting pretty high speed stuff to see flicker IMHO. Advance, Fulham, Universal--all the major ballast manufacturers are putting out a product that should work well for most film and video work.
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#5 Carl Brighton

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Posted 25 May 2007 - 08:08 AM

Hello everyone. I will be shooting a short on Super 8 soon and am wondering about a new fluorescent lamp I saw tonight at the hardware store. I saw a "Full Spectrum" tube like the type used in Videscense units or the type meant to replace a regular household lamp bulb. The 23 watt power consumption version puts out slightly greater than a 100W equivalent tungsten lamp. It says they are rated at 5000K.

Sean

Most fluorescent lamps use a mixture of an orange-red and greenish-blue phosphors which produce light that resembles white light but really isn't white. If that sounds a bit confusing, it's because it is!

What that means is that if you illuminate a piece of white paper, half with light from a full-spectrum source such as a QI incandescent, and half with light from a fluorescent with the same colour temperature (which is achieved by varying the mixture of green and orange phosphors) both areas of the paper will look the same.

The problem is, WHITE things look the same, coloured things DON'T.

A "full spectrum" fluorescent has a mixture of red, green and blue phosphors which more closely approximate the spectrum of true white light. Kinoflo's and the like use that sort of phosphor. While this is an improvement, it still isn't as good as a proper tungsten light, which is why they remain so popular despite their low efficiency.

Normal tungsten bulbs only have a colour temperature of around 2,200 - 2,700 degrees by the way.


A cheap and workable alternative is the QI garage lights that you can get pretty cheap in hardware stores these days. You usually get two 500W lamps with an orientable stand, and you'll find them very useful for non-film related activities too!
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Glidecam

Abel Cine

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Media Blackout - Custom Cables and AKS

Gamma Ray Digital Inc

Paralinx LLC

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Technodolly

Rig Wheels Passport

Metropolis Post

Willys Widgets

Broadcast Solutions Inc

The Slider

Visual Products

rebotnix Technologies

Tai Audio

CineTape