Bulb Questions

Why did you make your own Cool Lights fluorescent biax tube?

In the beginning Richard was just going to search for some low cost CRI 85 tubes to sell on the website because you mainly find CRI’s in the 80-82 range or 90 but not much in between. Through various circumstances he ended up with a major league education on how fluorescent tubes are made, how higher CRI’s are achieved, why it is harder to make higher CRI bulbs, etc. At the end of the process Richard had the tube manufacturer very interested in supporting him in offering a “just under 90” CRI, reasonably priced bulb to compete with the likes of the Studio grade bulbs from Osram or General Electric. Just remember this practical advice about CRI. Richard completed several video projects using fluorescent biax and CFL’s that were CRI 80ish and he never once saw a green tint to any of the video or any other artifacts that he thought were unacceptable. These “green” artifacts are far more likely to show up in film and not with digital mediums.  So, if you are primarily doing digital video work (and not traditional film) then you will probably never have to worry about it as long as you are careful with consistency of color temperature and use custom white balance with your digital video or still camera.

Will Cool Lights biax tubes work on 220v / 50 hz that we use in my country?

One of the nice things about biax bulbs (like the ones we carry) is that they are independent of a country’s voltage type. Since they operate off of a ballast, they have their own proprietary voltage requirements which are supplied by the ballast that drives them. Therefore, if the ballast works in your country, our biax (and anyone’s biax) tubes that are driven by that ballast will work in your country! Our Cool Lights ballasts are universal voltage, so if you use our fixtures there is definitely no problem in adapting.

Are Cool Lights biax tubes dimmable?

Yes. No problem–all biax 55 watt tubes are inherently dimmable. Like the question about whether a biax tube will work off your country’s voltage the answer is the same here. It all depends upon the ballast. Is the ballast you use a “dimmable” ballast and does it have all the associated hardware along with it to make dimming happen. Thus, our bulbs work with both dimmable and non-dimmable Cool Lights Softlight Series fixtures as well as competitor dimmable and non-dimmable fixtures.

What color temperatures are available for the biax tubes?

The very standard 3200K and 5600K were chosen for our products. White balancing on all types of cameras usually falls into the tungsten or daylight categories and 3200K and 5600K represent these (respectively).

What is the difference between the 3200k and 5600k bulbs. Why would I choose one or the other?

You’ll normally find the two choices in fluorescent tubes to match existing lighting as color temperature differences aren’t usually wanted. So, if you have some tungsten fresnels to use for hard background or rim lighting (like mentioned above) then you would want a 3200K tubes in your Cool Lights fixtures to help out with key and fill soft lighting. Matching to incandescent household lighting is another time you might need the 3200K tubes. If you’re in a room with sunlight streaming in (and you can’t or don’t want to block off the windows), you would normally want to use all 5600K lighting to match the sunlight; so, that’s a place where the Cool Lights metal halide Hardlight option would come in handy if you need hard light to complement the Cool Lights Softlights (or the Softlights turn out to be too weak to compete with the sunlight) because they come in daylight color for all wattages and also a tungsten color for the lower ones like the 150w type. This is why you hear of HMI units being used so often when productions are going on outside during the day or in a room where daylight is coming in–metal halide hard light really helps “fight” the sun when it’s needed.

What is the CRI of the Cool Lights biax tubes?

Cool Lights decided on a CRI of under 90 as a design compromise. CRI 90 and above fluorescent tubes are notoriously inefficient in the amount of light they put out. CRI 87 is a great compromise which provides a high quality color rendering at whatever correlated color temperature you are using but still puts out the amount of light we expect from an energy efficient fluorescent tube.

Do you have test reports available showing the parameters of your biax tubes?

Yes. In general if you are proud of a product then you don’t mind sharing all the aspects of it. If its not so great you don’t talk about it very much. Many of our competitors offer a cheap 6400K CFL or some other standard, off the shelf, color temperature (see why in our article on Color Temperature and Color Rendering Index). And just look here for our Cool Lights Biax Bulb test results.

Will Cool Lights self-ballasted CFL 200w bulb work on 220v / 50 hz that we use in my country?

A drawback of a self-ballasted bulb like the 200w 8U bulb we sell is that it is single voltage only.  We currently only stock a 120v 60HZ version in both 3200K and 5600K.  Perhaps with enough demand we will stock a 220v 50HZ version in the future–or technology permitting may find a universal voltage self-ballasted 200w bulb.

Are Cool Lights self-ballasted CFL bulbs dimmable?

No.  The ballast in the base of a bulb like the 200w 8U bulb must be capable of dimming and the one we sell is not.  To reduce the intensity, we recommend extra diffusion in front of the bulb which works well and doesn’t have any color temperature shift issues associated with it.  Trying to dim the 200w 8U bulb with a line voltage dimmer will most likely damage it and invalidate your warranty for the bulb!

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