making tungsten look like fluorescent, not fluorescent look like tungsten

[Marcus Marchesseault]

My softbox uses standard "mogul" base bulbs (Edison 39?). They are like the big brother to the standard medium edison screw-in found in most homes. It is a semi-standard socket for some industrial fixtures, so guess what? I found a 200W daylight-balanced, high CRI, mogul-based fluorescent. It is as big as a football, but it is fairly bright for a daylight softbox and doesn't heat up the room much. It is nice in that it's morphology is a cluster of tubes pointing out from the base. When I take the silk off the front of the softbox I get a somewhat directional source. I can even reign it in a bit more with the fabric grids.

It would be nice to have a CRI that describes the mired shift, but I have never seen such a thing on any regular fixture. Perhaps quality HMI units have this listed? What some fluorescents have is a graph of their output across the visible spectrum. I think a "high CRI" fluorescent is defined as having a more even curve without any pronounced spikes. This is probably the best we will get.

BTW, I have seen a 1000W metal halide bulb that has something like a 96CRI at 5600K! It puts out lumens completely into the ludicrous range. I seem to recall that it puts out about 3-4 times the lumens per watt as a tungsten and it is daylight balanced where you need the stronger light.

I hate to say it, but if you want to research daylight-balanced light, or anything but tungsten, you might find yourself on sites meant for growing plants indoors (horticulture?). A popular plant that is grown indoors is intended for "medicinal" purposes. Just thought I'd let you know you might find useful information around some of those places so don't avoid clicking even if you see something unusual.

[Charles Papert]

As is the case with listed (nominal) color temperature on a flo tube, the mired shift even if noted anywhere needs to be checked by meter on the individual tube as plenty of fluctation is possible. In fact, this is even the case with those expensive HMI's. It is common to see handwritten notations on the back of HMI heads that indicate what level of plus or minus green should be added to bring it to neutral. It is also the case that most fixtures change as they age (a tungsten light will become cooler when it is getting ready to blow, for instance).

On "The West Wing", DP Tom Del Ruth had spec'd a lot of MR16 globes into the permanent lighting plan--those hot overheads that viewers of the show may remember that peppered the hallways (actors would briefly "go nuclear" when walking through them) were MR16 halogens mounted above the ceiling, shining through holes cut out to resemble standard 6" lighting trims. Also he had custom "bat strips" mounted as backlights--these were arrays of multiple MR16's laid out in a line and housed in a lightweight fixture which would deliver a lot of puch but have very little vertical footprint. With a bit of diffusion, they cast a single relatively soft shadow. The problem with these were that they needed to be checked weekly for color shift, as it was a known fact that these type of bulbs have a tendency to go "funny" as they age. The best boy electric would walk the entire set with a color temp meter, measuring each fixture and replacing bulbs as needed.

Once again, though, video is much easier to work with in this regard as it is a WYSIWYG medium--if it looks green to eye and/or to the monitor, add minus green until it doesn't. Same thing with color temp.

[Bill Davis]

If I read your post correctly, you don't mind the color temp of the overhead flo's - you just want facial fill that matches.

I used to run into this a lot when I was starting to do a lot of retail store work. My solution - go with the flow...

I bought a couple of super cheap 4-tube fluorescent "shop light" fixtures and bolted a pipe elbow on one end so I could hang the sucker off a C-stand.

When I'd get to a store where the overheads were particularly nasty, I'd get a ladder and steal tubes from an actual store fixture out of the shot - and put those tubes in my cheap "front fill" light rig. Voila. Instant perfect color temp match - but coming from the front - rather than overhead. Store lighting is typically flat - but if you want more control get a roll of black wrap and get a handfull of clips.

In my experience, sometimes its useful not to overthink things too much.

Good luck.

[Cole McDonald]

If you're just looking to brighten up a bit, don't discount bouncing the existing light with a white card or silver reflector...this will perfectly match the color of the overheads and I've found it much faster than fiddling with matching lights in some circumstances.

[David Lach]

Might be personal preference, but I really like the look of greenish lit background and tungsten lit faces in some situations. I did a series of interviews in different repair shops recently and everything there was lit with fluorescents.

With some locations I used a 1/2 CTB on my main source, mostly when there was a little outside light spill from windows and doors. On others 1/4. And on some none at all. All dependent on the background's look, which was lit only with those flos. Then WB-ing on the main source.

I really like the seperation it naturally created between the guys working on the cars in the background and the person being interviewed in the foreground. And the greenish cast worked well for this "shop" look.

I used this approach a few more times in the past, all with good results. I find it works especially well for interviews where the eye is focusing on the talent and the background is very secondary and should be seperated as much as possible from the foreground.

In some cases such as these, I think you can mix flos and tungsten and create an interesting look without having to worry about matching the different color temps, controlling just how extreme the difference is with 1/4 and 1/2 CTBs.