Fluorscent Light bulb questions/ $22 or $59?

sputnikslim

sputnikslim

Active member
I have a bunch of Smith/Victor light reflectors/stands from still photo work and was looking to use them on an upcoming shoot with a DVXb into Final Cut. What are the pro/cons of using the two choices below? I know the mogul base/edison base difference and would need adaptors for the moguls. I've read about a green tint shooting with flo lights. Is that so? I'll be shooting puppets/sets indoors/blacked out on 4'x8' sets and want a very bright, but soft light effect. How many 85 watt or 200 watt bulbs should I get?
The 85w are $22 ea and the 200 $59 ea.


http://www.skaeser.com/servlet/Detail?no=525

http://www.coollights.biz/cl20056-cool-lights-200w-5600k-high-softbox-bulb-p-83.html
 
No green tint when shooting with a DVX or any digital for that matter. As long as the CRI is fairly high, that's only a film issue with the green. High CRI doesn't even really help with film and you have to look to other solutions there for that issue. None of our Cool Lights customers report green tint issues with any of our bulbs as they are all higher CRI figures. I can't speak for the other brand.
 
Thanks Richard. The other brand is Eiko and they mention a full minus green spike that is correctable with a "Lee minus green gel" that you wrap around the bulb.

Any thoughts on how many of your bulbs I would need? Is a single one of yours useful as a key light (two)?
 
So your sets are in the range of 4 foot x 8 foot in size. I would say one is probably useful as a key but if you were lighting a large area you may need something more like 2 or 3 of them. What size are these puppets? And how many of them are in a typical scene?
 
Cool Lights said:
No green tint when shooting with a DVX or any digital for that matter. As long as the CRI is fairly high, that's only a film issue with the green.
Click to expand...

I've got to disagree totally with this. Every florescent that I have looked at has a heavy spike in the green color range. The higher CRI help to balance that , but it is still there. I always use a 1/8 minus green when using flos. I have Kinos with true match lamps that have a CRI 95. Richard if you have flos without the green spike I'd certainly like to see the photometrics on it, because I'd be in a long line of people wanting to buy that.

Also depending on your white balance setting determines how much of a "tint" you might see from the flos.
 
Two per scene. They are hand puppets (like Muppets) and are about 1 1/2' to 2' tall ea.
The set is a little room scene with colorful furniture. Beige walls/blue floor.
 
Start with a couple of them and experiment with them to see the effect and if you like it. White balancing is in fact what saves us in the digital world. As long as all your fluorescent lamps are the same color temperature and there aren't any other sources of a different temperature, any potential green should white balance out.
 
Can someone tell me what minus green I should use on regular home depot bought flouresent bulbs that I would like to match with my tungsten lights?
 
Well first issue is to find some home depot bulbs that are close enough to 3200K that you won't see a color temperature difference. Once you do that then maybe a 1/8 or 1/4 minus green. 3000K or 3500K is about as close as I've seen at Home Depot to tungsten lighting.
 
True, digital is much more forgiving than film. Most film stocks emphasize the green spike of fluorescent so much (much more than our eyes) that the American Cinematographer's manual devotes a whole chapter toward how to apply gels to correct the specific green spike characteristics of different brands and models of commercial fluorescent bulbs found on location.

CRI is a very technical area (see Wikipedia), but essentially, it uses a standard sample of eight main colors and a few secondary colors, and compares them to a standard color space, reducing the difference to a CRI number.

There are lots of shortcomings to CRi when applied to any source with discontinuous spectrum (and that applies to ALL fluorescents, HMI/CDM, and other halide/discharge sources, such as sodium and mercury vapor streetlamps.) In addition to spikes, there are color wavelengths that are missing or less present. What this boils down to is that, even with a high CRI, a fluorescent tube only approximates a full spectrum, and the differences could result in certain subtle changes in color rendition (more or less saturated, or color shifts). A particular brand tube with a CRI of 85 could even have a more "realistic", pleasing color rendering in a real-world setting than another one with CRI of 87, because bulbs with different spectral shortcomings and spikes can "average" out to similar CRI's.

White balance is mandatory, no doubt. No one should shoot the presets under a fluorescent or HMI source, even with a high CRI. Yet even if you balance to a DSC Labs Camwhite card, the color rendition under fluos on certain colors will differ slightly from what you would see if shooting the same subject under the equivalent tungsten setup.

All this is pretty theoretical, so my best advice get to know your own lighting gear. Buy or borrow a DSC color chart and test with different light sources. Read and make note of the color temp reading that comes up in your viewfinder when you white balance. Dump the footage into FCP and compare the charts on the screen, and on the scopes. Note color shifts. Above all, educate your eye and then trust your eye.

You are a painter of light. Learn your brushes. Learn your paint. :-)


Mark Schlicher
Producer/Director of Photography
www.sunporchmedia.com
 
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Thanks for all the input on this. One more question; how much loss of wattage am I looking at by putting a full minus green over a flo bulb (either bulb)?
 
Cool Lights said:
Well first issue is to find some home depot bulbs that are close enough to 3200K that you won't see a color temperature difference. Once you do that then maybe a 1/8 or 1/4 minus green. 3000K or 3500K is about as close as I've seen at Home Depot to tungsten lighting.
Click to expand...


thanks !
I was considering getting a gel that would bring up/down the flo to match tungsten if needed.

I guess I can call the manufacturer because most bulbs I have seen there dont list the kelivins.
 
They are getting better at HD and the consumer outlets like that but for the most part they lump consumer / commercial class bulbs into categories. Remember this: a "soft white" or "warm white" is usually a 3000K. A "very warm white" is in the 2700K range. A "white" is 3500K. A "cool white" is 4000K to 4200K. A "daylight" is generally 5000Kish. A "daylight plus" is usually 6500K. Its a bit tougher to find the well-regarded 5600K range at a consumer outlet. The Home Depot N:Vision CFLs have a 5500K model which is close enough and many like it despite the fact that it has a CRI of around 82.

http://en.wikipedia.org/wiki/Compact_fluorescent_lamp
 
sputnikslim said:
Thanks for all the input on this. One more question; how much loss of wattage am I looking at by putting a full minus green over a flo bulb (either bulb)?
Click to expand...

Given that I never use minus green as I am careful to not mix color temperatures and I white balance to the lighting I'm using, I don't have much experience with this personally. An educated guess would be as much as a 1/4 stop loss of light perhaps.
 
Thanks Richard. Anyone else have experience using the minus green gel and how much light it takes away? I've read this about other gels but not on the minus green.
 
Tough minus green converts US cool white to HMI with 55% trans
fluorfilter converts US cool White to tungsten with 35% trans

So you lose a lot of light esepecially going to tungsten.
 
I'm confused now. So, by using a minus green on these bulbs, it will cut them in half? (aprox). I just want to control the green, not convert to tungsten. Is that what I am doing? Converting to tungsten? Not clear on this at all at this point.
 
Yes this is getting confusing. Why not just try the bulbs without any correction gel and see what you think? I say white balancing will take out the green as long as you're using all the same type lights/color temps. If there's some correction just experiment with a 1/8" minus green first but I don't think you'll need it.
 
Thanks Richard- I was actually trying to find all this out before I make a decision on ordering as it will affect the quantity possibly. Has anyone else used these bulbs on a shoot?
 
This doesn't need to be confusing and is something very important you need to know. First lets look at how much color makes up the light from a flo blub here;

http://www.kinoflo.com/Kino Flo lamps/True Match/True Match.htm

You see the heavy green spike of light. So if you place a magenta or minus green gel over that bulb you are removing the brightess portion of the light, thus why you lose so much brightness of the light.

Next consider what white balancing actually does. What it does not do is magically turn everything the "correct" color, instead it "shifts" the color spectrum. Here's a good article with a chart to show the difference.

http://www.3drender.com/glossary/colortemp.htm

Is it OK to just white balance under flos? yes and no, it depends on what you're shooting. I wouldn't want a saturated red and blue in the same scene, you're blue will be a bit muted and the red will be over saturated, instead I woud gel the light to get to a true 3200 white balance so the reds wouldn't appear so saturated and bleed all over the place.
 
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