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Old February 10th, 2007, 04:02 PM   #1
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2700k - 3500k or 5500k fluorescents?

I'm going to use (n:vision 27w ) fluorescent lights in a china lantern- but which is the best temp for for indoor shooting ( no outdoors ) If someone could break down the differences of 2700k - 3500k or 5500k options and which one is the best for bars, homes - small rooms etc all people . I don't want anything cold or overly warm ( temp ) just somewhere in the middle that will allow post production to decide but also work best with whatever light will be admitted from these locations besides mine- It is a documentary so the locations are not at all controlled.

Example ( not exact light bulb ) http://www.homedepot.com/prel80/HDUS...4+4233&pos=n12
( click Light Bulbs on the left)

Thanks
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Old February 10th, 2007, 04:39 PM   #2
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Old February 10th, 2007, 05:00 PM   #3
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Do you have any other light sources ? Other than matching, I don't think the color temperature matters too much.

One question I have is about using light sources with lower color temperatures has to do with white balance. During noise reduction processin, I've noticed that in a lot of my DSLR pictures taken in incandescent settings seem to have a lot of blue noise. Does this mean that using higher color temp sources would put less stress on boosting the blue channel ?
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Old February 10th, 2007, 05:16 PM   #4
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Best match for existing incandescent lighting will be 3500. Best match for existing fluorescent lighting is (probably) 5500 - but not always (warm white fluorescents are closer to 3500). Best match for sunlight coming through windows is 5500.

Ye' makes yer choices and ye' takes yer chances. Or, buy both and keep the 5500 packed up unless needed to match fluorescents or sunlight.

CTB gel will bring 3500 up to apx. 5500, with some loss of light. CTO gel will bring 5500 down to apx. 3500, again with some light loss.

So, you need to decide what you'll most often be wanting to match and purchase appropriately. Your camera will have no problem white balancing to either, and your editors will be happy if you don't mix color temps and light well.

Taking time to assure that the camera is color balanced and keeping all sources at apx. the same color temp will result in a neuteral appearance, neither warm nor cold.
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Old February 10th, 2007, 05:27 PM   #5
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When in doubt I tend to go with daylight lighting, I've been caught out when daylight crept into a tungsten lit scene and it looked just horrid, blue light isn't natural whereas a few 'warm' looking practicals look sort of natural.
Also probably of no scientific merit but for some reason daylight light source make people feel cooler which is one way to reduce the feeling of "I'm being cooked" for the talent.
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Old February 10th, 2007, 05:34 PM   #6
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Makes sense ( for the money ) to just get both 3500K and 5500K - Thanks
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Old February 10th, 2007, 08:01 PM   #7
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any light can be " neutral white " if you manually ballance for that temp. So this kind of anwsers your question about giving the post work flow final choice over the " mood " that the lighting will set. I take it that you are doing an artistic piece and not a corporate thing, and that you want the lighting to create a feeling. Please feel free to mix color temps within a setting. Pick a temp and ballace to that one as your white source, and then let the other temps help you paint your picture.
Setup a monitor and make sure your recording what your seeing. Then have fun with it.
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Old February 10th, 2007, 09:06 PM   #8
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Quote:
Originally Posted by Craig Chartier
any light can be " neutral white " if you manually ballance for that temp. So this kind of anwsers your question about giving the post work flow final choice over the " mood " that the lighting will set. I take it that you are doing an artistic piece and not a corporate thing, and that you want the lighting to create a feeling. Please feel free to mix color temps within a setting. Pick a temp and ballace to that one as your white source, and then let the other temps help you paint your picture.
Setup a monitor and make sure your recording what your seeing. Then have fun with it.
Yes, a really nice effect can be 2700K or 3500K primary lighting with 5500K coming to one side of someone's face (like daylight streaming in from a window). Gives a realistic touch if that's what you're looking for.
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Old February 12th, 2007, 03:45 PM   #9
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Quote:
Originally Posted by Craig Chartier
any light can be " neutral white " if you manually ballance for that temp.
I've always wondered about this assumption. Isn't that based on a nearly flat spectrum ? You can't really white balance a monochromatic source ? So, I'm wondering just how well we can balance light sources with irregular spectra, such as fluorescent lamps.
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Old February 12th, 2007, 07:38 PM   #10
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Why not put a tungsten lamp inside the China ball? Are you using a fluoro for a particular reason? You can also wrap a gel around the bulb if you need to alter the color. Just be sure to leave some air between the gel and the bulb.

Tungsten bulbs range from 75 Watts (PH211) to 500 Watts (ECT), that will give you proper color and high output. You can also use 4800K bulbs(250W BCA, 500W EBW) if you want a cooler look, or need to be closer to daylight.

Most folks use 250W ECA, or 500W ECT. All bulbs have a three letter ANSI code, so that regardless of manufacturer, you get the same bulb.

If I just need a little something, I'll use a 25W bulb, in a pratical, or in a China Ball. so long as it's tungsten/incandescent, it's in the color ball park.
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Old February 28th, 2007, 03:51 AM   #11
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Color temperature makes a difference in noise

Hey guys,

I always wondered about how the camcorder's white balancing affected noise. Here is a nice article on that subject :

http://www.imaging-resource.com/ARTS/TESTS/HMI.HTM

Q: What do you mean by "to the first order of approximation" when talking about image noise comparison?

A: Image noise is to some extent dependent on the color balance of the light source a camera is being tested under. Or, more accurately, on the match between the color balance of the light source and the native white balance of the device under test. Most digital cameras are designed to have a "neutral" white balance under normal daylight lighting, at a color temperature of roughly 5500 Kelvin. When shooting under warmer-toned lighting, the camera has to increase the gain of its blue channel (and to a lesser extent, sometimes of its green channel as well) to achieve a neutral color balance. Boosting the gain of the blue channel also boosts its noise, so warmer-toned light sources tend to make for noisier images, at least in the case of the camera's white balance being adjusted to produce neutral balance in the final images.

Because our previous light source was a few hundred degrees K warmer than the new HMIs, noise levels of older cameras will appear slightly elevated relative to those shot under the newer source. The difference should be slight, because the color temperatures aren't all that different between the two sets of lights, but we mention it for the sake of accuracy and completeness.
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Old February 28th, 2007, 08:47 AM   #12
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Mike, I use both the N:vision 5500k and 3500k bulbs in the same fixture.
I purchased a 9 socket fixture that has 2 circuits.
Circuit 1 has (5) 5500k bulbs and Circuit 2 has (4) 3500k bulbs.
The 5500k bulbs have a high CRI Value and therefore less output.
It seems to work out that (5) 5500k bulbs put out the same (or close) lumens as 4 of the 3500k bulbs.
Gary
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Old February 28th, 2007, 10:18 AM   #13
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3500 K is pretty blue compared to incandescents and Tungsten. Tungsten is 3200k and practical bulbs are often below 3000K. In this color temperature range 200K is very noticeable
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Old March 1st, 2007, 01:36 PM   #14
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Mike, I forget to add that the 5500K bulbs make excellent grow lights and I have to constantly steal them back from my wife.
Gary
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Old March 2nd, 2007, 08:11 AM   #15
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daylight fluorescent bulbs

Daylight balanced GE Chroma 50 bulbs are supposed to have a high color rendering index to eliminate funky fluorescent green color spikes.

I was looking for those bulbs and asked the Home Depot guy about them. He said I could ask the sales rep about them for special order.

I bought several Ecolux Sunshine F40 bulbs and they actually are Chroma 50, it is printed on the bulb itself but not on the paper wrapper that it comes in.

One thing to check if you buy these. Several of them had loose end caps on the bulbs and a couple actually fell off before I even used them. I'm sure they just had some duds but when I buy more I will check each one to make sure this won't happen.

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.

Has anyone noticed strange color shifts or flicker in their video when using different types of fluorescent bulbs, either the shop light type or the screw in kind? The screw in types have built in ballasts and screw into regular fixtures.

Last edited by Larry Vaughn; March 2nd, 2007 at 08:14 AM. Reason: add info
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