5500K vs. 6500K
 

Is it ok to mix 5500K with 6500K lighting? Are these close enough that it won't mess up white balances? At a trip to the local Home Depot I discovered:

The only spiral lights I can find are 5500K N:vision 100w equivalents (27w real). I want to drop 3 of these in a Chinese lantern.

The only 4' tube (T-8 type light for an electronic ballast) is the Philips 6500K.

I guess I shouldn't say the ONLY ones I could find, but the ones in the fluorescent color temp. range I need.

Are 5500K and 6500K going to look different enough to notice on an Canon A1 or HV20 camera?

yes they will look different. depending on where you set your WB point, one will look cooler or warmer. easier to warm ( less light loss ) so to match your 5600K source add some 1/4 ( or 1/2) CTO to the 6500K and they should match.

then again, it all depends on what you are looking to deliver.

Like Steve insinuated - a little bit of difference might look good... it all depends on your goals, your intended look of the program. And as always, you can gel the light fixtures to control the color temperature.

I would like to use some of Richard's 650w equivalents for hardlighting, but I want most of my fill to be fluorescents (tubes and spirals). His hardlights are 5400k. I found some 5400K fluorescents, but they're around $20 each. http://www.servicelighting.com/catal...m?prod=QQ18541 OUCH!!!

I found some 5765K fluorescents for $10 each. http://www.servicelighting.com/catal...m?prod=QQ17944 Still OUCH, but not as bad.

Would the 365K make that much difference? Is it worth the $10 price difference (times 20 bulbs) for 365K?

As a follow up question, would this work?

A $3 4100K http://www.servicelighting.com/catal...m?prod=TC00988
combined with a $6 6500K http://www.servicelighting.com/catal...m?prod=SL22175

Alternate those two tubes every other one, perhaps throwing up a diffuser to blend the colors better?

Is this oversimplistic math? 4100K + 6500K / 2 = 5300K

Does the math work out that easily in lighting or are there other factors? If it DOES work out, how about the 100K difference between the fluourescents and the 5400K CDM lights at coollights.biz? Is it even going to be noticeable?

A 100K difference at a higher color temperature is very hard to see and you probably can't see it. A 100K difference at a lower color temperature like 3200K though can be quite noticeable. I don't think you'll find it so easy to mix color temperatures like that to make another color temperature. There are all kinds of other factors that can come into play and may make the results unsuitable for video work. On the other hand, it could work but you can't really know until you try it whether you'll have white balance confusion issues.

That's an interesting idea, however you should know that fluorescent tubes do not really have a color temperature. They merely have an approximation to one, called the correlated color temperature. Even if they had one (like tungstens), the sum of two lights with different color temperatures is not white, and therefore has no color temperature.

Also, the higher the color temperature, the less a constant difference between two color temperatures becomes perceptible. This is why gels are measured in mireds, which is given by the shift of the reciprocals of the color temperatures.

All this is irrelevant to whether or not you like the final result, so try it if you can afford to, otherwise try to minimize the number of light sources with different color temperatures.

I tried this ONCE. a 24" 3200 and 5600 in the same fixture and it was uck! I didn't try to mix it with a diffuser. I think the 5600K bulb was actually brighter, so it was more 5600K with some warmish light. just didn't work. better to CTO a cool source then CTB a warm one. CTO= 2/3 stop, CTB=1 2/3 stop loss.

Thanks. Specific to your lights you sell (the 650w eqv. 5400K), would a 5000K bulb (hence 400K difference) be very noticeable? I can get 5000K tubes cheap at HD.

Yeah, I hadn't thought of that. What do you think it would take to bring a 6500K fluorescent to 5400K?

You should be able to find daylight fluorescent T8 tubes in your area. Both Home Depot and Lowes have them around here. The ones at Home Depot were not labeled properly, but they are good daylight T8s in a simple corrugated paper wrapper.

I can find tubes marked as "daylight," but they are either 4100K, 5000K, or 6500K. The Coollights I'm getting run at 5400K and I want to run the fluorescent tubes with the Coollights fresnels.

Probaby not so noticable. I would definitely go for a 5000K before I would a 6500K.

I agree. Go with the 5000K as a bit warmer looks better on skin than 1000K cooler.

I've been using the Philips 950 T8 5000K tubes which are advertised with a high CRI, although they're not available at Home Depot. The trouble with these is that you usually have to buy a case of them from wholesalers. I think you mentioned buying 20 bulbs, so the case is closer to what you want at about $8/tube. Try this source for both your spirals and tubes:
http://www.atlantalightbulbs.com/eca...p?search=5000k

I bought the cheapo Lithonia four tube T8 fixture from Home Depot for something like $35 and replaced the Ts. Home Depot also carries the excellent Philips ColorTone50 T12 tubes, and if you break the case, you can buy them for half the price of the individually-packaged tubes.

Oh, I just noticed Mr. Andrewski in this thread. Consider checking out his Cool Lights instructional DVD.