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Old March 2nd, 2007, 11:59 AM   #16
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Originally Posted by Larry Vaughn View Post
...I've read that the ballast in the fixture can keep any 60hz flicker out of the shot. Supposedly cheap lights (like shop lights) have cheap ballasts that won't prevent this. ...The screw in types have built in ballasts and screw into regular fixtures.
Right. If you are purchasing fixtures for video use you want electronic ballasts, which run at something like 20-30KHz, rather than magnetic, which run at 60Hz.

Screw-in fluor. aka. CFL bulbs have built-in electronic ballasts.
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Old March 2nd, 2007, 11:17 PM   #17
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twisty light deal

The Home Depot in Gainesville, Florida is selling the N-lights for about $1.00 each. They are having a promotion in conjunction with GRU, the local power company. Only the green packages are cheap, the daylight bulbs in the blue packages are the normal price. The guy stocking the shelves said they have sold thousands of them.

I bought some ceramic fixtures at WalMart for $2.00 each and intend to put several in the mounting plate of some Larson softboxes. The mounting place is flat aluminum and should hold 16 of the bulbs, maybe more, depending on which wattage bulbs I use. At least I can test them without spending too much money and the softboxes are pro units and look that way.
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Old March 3rd, 2007, 10:44 PM   #18
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Originally Posted by Larry Vaughn View Post
The Home Depot in Gainesville, Florida is selling the N-lights for about $1.00 each. They are having a promotion in conjunction with GRU, the local power company. Only the green packages are cheap, the daylight bulbs in the blue packages are the normal price. The guy stocking the shelves said they have sold thousands of them.

I bought some ceramic fixtures at WalMart for $2.00 each and intend to put several in the mounting plate of some Larson softboxes. The mounting place is flat aluminum and should hold 16 of the bulbs, maybe more, depending on which wattage bulbs I use. At least I can test them without spending too much money and the softboxes are pro units and look that way.

If you have fluroescent, why use a softbox? The hood may make a great reflector but there's not much need for the silk diffuser in this case. the N:vision in the green package are 6500K i believe if i'm not mistaken.

As for your earlier post, you can find bad self-ballasted that flicker and many that don't. I've had good luck with the N:Vision brand self-ballasted ones in 5500K and 3500K for flicker and color rendering is okay for many uses.

Home Depot has magnetic ballasted fixtures and electronic ballasted also. You can even find clunker electronic ones. There are some that flicker believe it or not but most don't. Its getting harder to find the poor ones anyway because the public is getting more educated about some of these issues.

Notice how CRI is printed on the package of most fluorescent bulbs now. A few years ago, most didn't even know that there was a CRI figure to quote. At some point in the future many of the lowest CRI bulbs from 65 to 79 may fade away completely and we'll only have 80 or above as the educated public becomes wider and wider and as the price is driven down even more of the 80's and above.
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Old March 4th, 2007, 12:46 PM   #19
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I've heard...

"It doesn't matter what you use as long as they're all the same color."

Is this still true?

I noticed the home improvement stores sell soft white florescent bulbs with a 4100K color temp. They make bulbs that fit every socket I have.

At 4100K you can gel them to 3500K or 5500K. They pull less power and don't produce as much heat. If the above statement is true then there isn't any reason to use any other kind of light. $100 in gels and I can shoot anywhere.

Is this correct?
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Old March 5th, 2007, 10:18 AM   #20
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Originally Posted by Dennis Khaye View Post
I've heard...

"It doesn't matter what you use as long as they're all the same color."

Is this still true?

I noticed the home improvement stores sell soft white florescent bulbs with a 4100K color temp. They make bulbs that fit every socket I have.

At 4100K you can gel them to 3500K or 5500K. They pull less power and don't produce as much heat. If the above statement is true then there isn't any reason to use any other kind of light. $100 in gels and I can shoot anywhere.

Is this correct?

Well I've gone totally fluorescent personally for the things I do but you can't really say what you said though as a general rule. Sometimes people need a hard light (for dramatic or whatever reasons--perhaps they need well-defined shadows for example) and fluorescent can't be a hard, focused point light. The surface area of any fluorescent bulb is so large that by its nature its impossible for it to be anything but diffused, even if you add a great reflector. You could try to add a lens but the result would probably be pretty weak. Really the best energy efficient source for hard light is an HMI or ceramic metal halide (which can reach CRI 95). Both these types require a ballast to convert line voltage to the voltage needed by the bulb to start and maintain its internal "high intensity discharge."

But these are still very hot lights compared to fluorescent. I can touch my 200w 8U fluorescent bulb when its ventilated out in the open and not covered by a softbox. I wouldn't dare touch my 150w ceramic metal halide though. It puts out a lot of heat but is still more energy efficient than tungsten by at least 3 times (150w CMH = about 450-500w tungsten). And I have a good choice of color temps which I don't have with HMI (HMI is exclusively 5600K to my knowledge).

There are other issues with the bulbs. For example, I wouldn't use an HMI or a ceramic metal halide outside of a hard shell fresnel or flood light with explosion proof glass UV protection glass on it. They've been known to emit UV (in some models without an extra glass envelope over the bulb) and also have been known to explode (but it's rare).
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Old March 6th, 2007, 09:39 PM   #21
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Light experience

I tried a couple things. First, in the Run What You Brung mode, I used the modeling lights in some Ultra 1800 monolights I had with softboxes lined with silver reflectors. They worked ok for the video but the bulbs (bba) pick up some interference from the strobe electronics and that turns into a strange noise that the me66 picks up big time. There is no way to turn off the strobe circuitry without turning the modeling lights off also. The same bulbs are quiet when run alone.

So that is out.

Then I held my light meter in contact with one of the twisty fluorescents. ISO 100, 1/30 sec...f 32. That drops to f 1.0 and a half stop at 4 feet away. 16 bulbs in theory would mean f 4 and a half stop at 4 feet. That might work but I'd like to use my XH-A1 with -3 gain for less grain and a faster shutter speed.

If I add another 16 bulbs for fill above the lens or nearby, as I would do for still portraiture, I might get by with that and wouldn't need to diffuse the fill, but I might want some type of enclosure for protection and I could just install some $2.00 ceramic sockets into the inside of the softbox mounting plates. It also helps keep direct light out of the lens without having to gobo the lights.

But, if I put one of those bulbs up to my ear, I hear the ballast humming. Multiply that by a boatload of bulbs (at $1.00 each plus $2.00 for the sockets) I think my mic would pickup some sound that I don't need. By the way, when I put my ear on the ballast of some $8.00 shop lights from Lowes with 2 Chroma 50 bulbs I hear less noise than what comes from the twisty bulbs. Those shop lights are out for me because I'd need 8 bulbs for enough light and the size is difficult, unless I was using them for accent like specular highlights on something or a wall wash.

So for the time being I'm going with quartz hot lights in heat resistant soft boxes. I like the look that the soft boxes give to people, the bulbs blast light and everything is easy to transport. Plus, some of the less expensive alternatives look cheap to clients.

Last edited by Larry Vaughn; March 6th, 2007 at 09:43 PM. Reason: add info
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Old March 7th, 2007, 02:02 AM   #22
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When it comes to fluorescents, you really need Kino Flos, or something similar. They use high frequency ballasts, so they don't make much noise, or create too much interference and their tubes match perfectly with tungsten, or daylight sources, depending on which you choose.

A fluoro can be a hard source. When you move it farther away from the subject, the size of the light, relative to the subject, decreases. So, your lovely 4'x4Bank Kino gets contrastier and harder as you move it farther away. Because of the nature of the source, your f/stop drops quickly as you move away from the subject. Tungsten has more punch.

The reason to stay with 3200 Kelvin, or 5500 K is to be able to match with other lights. I'll be working on a TV show where the cameras go in and out of the houses that the hosts are fixing. All of our lighting will be daylight balanced, so that the color is consistent wherever we go.
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Old March 7th, 2007, 09:57 PM   #23
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Originally Posted by Mark Sasahara View Post
When it comes to fluorescents, you really need Kino Flos, or something similar. They use high frequency ballasts, so they don't make much noise, or create too much interference and their tubes match perfectly with tungsten, or daylight sources, depending on which you choose.
Most all the professional fixtures today use high frequency ballasts. Including our Cool Lights ones which have a ballast output frequency of 40KHZ. It's harder and harder to justify the price difference unless you're doing film and you need bulbs with a majenta minus green correction.

Quote:
Originally Posted by Mark Sasahara View Post
A fluoro can be a hard source. When you move it farther away from the subject, the size of the light, relative to the subject, decreases. So, your lovely 4'x4Bank Kino gets contrastier and harder as you move it farther away. Because of the nature of the source, your f/stop drops quickly as you move away from the subject. Tungsten has more punch.
A less complicated way of saying that is the drop off is steeper with fluorescent, hard lights like tungsten have a longer throw.

Quote:
Originally Posted by Mark Sasahara View Post
The reason to stay with 3200 Kelvin, or 5500 K is to be able to match with other lights. I'll be working on a TV show where the cameras go in and out of the houses that the hosts are fixing. All of our lighting will be daylight balanced, so that the color is consistent wherever we go.
Most household lighting could be tungsten and is 2700K or so. I personally wouldn't want 2700K lamps for my pro fluorescent fixtures. I would prefer to turn off all the practicals and use daylight 5600K to match anything coming in the windows.
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Old March 8th, 2007, 12:59 AM   #24
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Originally Posted by Richard Andrewski View Post
Most all the professional fixtures today use high frequency ballasts. Including our Cool Lights ones which have a ballast output frequency of 40KHZ. It's harder and harder to justify the price difference unless you're doing film and you need bulbs with a majenta minus green correction.
What we're shooting has to match daylight because the cameras are rolling as they walk in and out of the houses I'm lighting, so they have to be color correct. Kinos have the highest CRI and match daylight, or tungsten seemlessly. We're shooting on HD, but even if we were shooting SD, I wouldn't settle for anything less.

Video does have the ability to integrate inferior fluorescent bulbs that don't match exactly. I've used shoplights on projects and was amazed that they integrated as well as they did with tungsten.

Most of what I shoot is video and I use Kinos almost all the time. They are easy, fast, cool in temperature and make beautiful light. Plus just swapping out the tubes gives me tungsten, daylight, or a mix. Select ballasts let me control all four tubes on a 4Bank fixture.

I like the Kinos because I can use them in the fixture, or take the tubes and harness out and tape the bulbs and harness to the ceiling, or wall. I've put them in cars, incorporated them into the set, where they're seen by the camera and stuck them all over the place. They come in many diferent sizes and color temps, are very robust and can handle everyday use. It's a great system.

It's harder for me to justify me NOT using them.

Quote:
Originally Posted by Richard Andrewski View Post
A less complicated way of saying that is the drop off is steeper with fluorescent, hard lights like tungsten have a longer throw.
No you are not getting the point. I'm talking about the quality of light, not just the quantity. The point is that any light becomes smaller as you move it farther away from the subject, making it harder and contrastier. Keep moving the light back and it eventually becomes what amounts to a point source. It's size relative to the subject becomes smaller.

The light from a large soft source, like a softbox, wraps around the subject at three feet. Light travels in a straight line. The face of the softbox is throwing light all over the place, the light is bigger and diffuse and so hits a wider area, making the light soft. At twenty feet, it becomes less soft and more specular. Ony the light rays travelling from the softbox face, that are in line with the subject, are going to light the subject. So, less light reaches the subject but also only the light in line with the subject, so the light no longer wraps around the subject. It's contrastier.



Quote:
Originally Posted by Richard Andrewski View Post
Most household lighting could be tungsten and is 2700K or so. I personally wouldn't want 2700K lamps for my pro fluorescent fixtures. I would prefer to turn off all the practicals and use daylight 5600K to match anything coming in the windows.
Yes, that's what I'm saying, we're using the daylight Kinos to light up the work areas and pretty much the entire house. Practicals are shut off, or we we just leave them tungsten. There isn't the time to muck with them, plus production wouldn't give me blue bulbs, or worm lites.

Generally I think most household incandescents are about 2900 degrees Kelvin. Kino makes 2900 K tubes :~). That way if you are using lots of low wattage lights, you can match them.
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