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

Moved from Open DV to Photon Management.

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 ?

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.

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.

Makes sense ( for the money ) to just get both 3500K and 5500K - Thanks

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.

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.

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.

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.

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

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

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

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.

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.

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.

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.

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).

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.

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.

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.

A less complicated way of saying that is the drop off is steeper with fluorescent, hard lights like tungsten have a longer throw.

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.

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.

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.



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.