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Canon XH Series HDV Camcorders
Canon XH G1S / G1 (with SDI), Canon XH A1S / A1 (without SDI).


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Old September 5th, 2007, 06:16 PM   #1
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Question about color temperature and resulting colors in video

I understand the color temperature bit (I think) and I understand the white balancing concept.

My question is:
Since one should white balance using the key light. Does it matter what the temperature of the ket light is? I mean can lights with different temperatures produce different results even though the camera was white balanced before the shoot?

I'm on my way to making a softbox using compact florescent light bulbs and was wondering what color temperature bulbs I should buy. Most of the bulbs have a CRI of 82 and some 84.

My other lights are 5500K (or at least thats what the camera tell me).
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Old September 5th, 2007, 07:13 PM   #2
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Unless your other lights are HMIs or fluorescents with daylight lamps, they probably aren't 5500K. You should keep all your lamps at about the same color temperature. You can buy daylight (5500K) fluorescents. I use Lowel Caselights a lot for shooting interviews and switch the lamps out all the time between 3200 and 5500.
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Old September 5th, 2007, 07:17 PM   #3
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typically, what you see is what you get in the vf. you can manual set the white balance or use the presets at the top of the cam and tweak it.
fluorescent lighting is going to give you a colder color temp and if that's not what you want, you'll have to warm up the color temp anyway. i believe most pro fluor lights are balanced for daylight at 5400k-5600k. frankly, for that i'd just hit the home depot, go cheap, and tweak in camera. for a "pro" small-scale soft box, i prefer tungsten at 3200K ..200 to 500 watts.

edit- like bill mentioned.. if your budget permits, go with lowel. great kits, flexible, rugged, and not very expensive.
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Old September 5th, 2007, 07:35 PM   #4
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The Lowel Caselights are just around $900 for a 2-lamp, and about $1200 for the 4-lamp. There are some cheaper fluorescents out there, but you pay more for the convenience of everything folding up nicely and ease of handling and control.

I like using daylight lights most of the time for location shooting because there's usually some ambient daylight that can be used. In more controlled situations I use tungsten.

You can white balance to just about anything; that's not the issue. The problem is in keeping color temperature everywhere in the scene constant, unless you're looking for specific effects. For instance, if you light with tungsten and there's a window, all the daylight will look blue.

Most fluorescents I run into in offices seem to check out at around 4200-4700K when I masure the color temperature. I have run into some that are over 7000, really weird.

Of course you can always gel your lights to match what you need.
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Old September 5th, 2007, 11:45 PM   #5
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Bill,

My other lights are not HMIs. They are halogens. I used to wonder about the 5500K myself. But for some reason the camera shows them to be 5500K. I thought the reading I see on the camera was supposed to tell me the color temperature it sees. Is that not so?

I'm looking at the making a softbox using compact fluorescents, some foamcore and ripstop nylon as the diffusion material. I'm thinking of using about 10-12 bulbs giving me about 1000W.

The issue is that depending on the color temp of the bulbs and the CRI prices (per bulb) range from $1.5-$12.
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Old September 5th, 2007, 11:50 PM   #6
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Eric,

The compact fluorescents I'm talking about (available at Home Depot) don't produce a "cool" light. As in they are warm (color temp) around 2700K. In other words they are unlike the old "tube lights" that one seem in most offices.

You get various color temps ranging from 2700K, 3100K, 3200K, 4100K 5100K, 5500K to 6500K. So what I'm really wondering is do it matter? That is other than having to match other lights/ambient lights?

I've heard people say "dail in more warmth" but I'm not sure how to do that yet :).
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Old September 6th, 2007, 12:02 AM   #7
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The camera can be white-balanced at only one color temperature.

Therefore, for example, if you balance at 3200, everything with a higher number will look more and more blue.

Every light with a color temperature lower will look more and more warm.

You can mix color temperatures, but you will have differences in the picture depending on the temperature of the lights.

In an interview, if you balance for the person, it probably wouldn't matter if the background was a different color temperature as it could be a nice effect.

Also, if you gel your lights for the background, say, the color temperature won't make as much difference if it is difference than your subject light.

You might use a daylight temperature on the face and balance for this, then use a warmer backlight on the head. The result would be a golden halo around a naturally looking face.

Etc. Etc.
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Old September 6th, 2007, 01:12 AM   #8
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Jack,

Yes, what you says makes sense. I understand that ideally one wants lights of the same temperature so one can controll (using gells and stuff) things better.

Thank you all for your replies.
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Old September 6th, 2007, 09:41 AM   #9
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Shiv, the Canon will not give you a readout of color temperature. I assumed you were using a color temperature meter or had checked it with a different camera. If you're talking about the 5500 position of the switch, that's for a 5500K preset.

I use the presets mostly, either 3200 or 5500, when I have control over the lighting. The only times I white balance are when I am using available light. I have a setting that warms up the colors a bit, and if I white balance, that warmth would go away, which is why I keep with the presets for most things where I have the opportunity to light the scene.
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Old September 6th, 2007, 02:28 PM   #10
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Bill,

Gosh, I actually thought the camera (XH-A1) was giving me a light temperature readout :). I even remember reading in the manual that it could do that.

If not then my "other" lights (being tungsten halogens) are 3200K.
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Old September 6th, 2007, 02:46 PM   #11
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Unfortunately the camera does not provide a color temperature readout. Since it knows what the CT is when it white balances, it should be easy to provide that readout in the viewfinder, but they don't. Very annoying.
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Old September 6th, 2007, 03:21 PM   #12
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That is a feature that is found in higher-end cameras, but you are right in that it could be easily incorporated into the software of this range of camera (particular the Canons who don't have to protect their high-end).

One thing to be aware of when mixing and matching consumer lighting is that color temperature is not the end of the story, there is also the mired shift which ranges between green and magenta. Fluorescents have traditionally shown more green than incandescent lights although they have improved over the years. If you had a fluorescent that magically measured 3200 degrees and used it in the same scene as a 3200 degree tungsten unit, you might still see a difference due to the mired shift. This can easily be corrected with the appropriate gel (plus or minus green on one or the other fixture).
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Old September 6th, 2007, 03:32 PM   #13
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Charles,

Thank you for the heads up.
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