Mixed lighting
 

As a general rule I read SOMEWHERE that it is not a good practice to mix halogen lighting with florescent lighting. Is there any truth to that?

perhaps with off the shelf "cool whites," but no, there's not a lot of truth to that. If the tubes are color matched to "tungsten" and used alongside halogens, you'll find they work quite well with one another. Otherwise, you can intentionally mismatch their colors for warming/cooling/disgusting effect.

I recently lit an interior matching warm white tubes to halogens, (shooting video), and with cameras white-balanced to the halogens, the look worked with a subtly warm fill from the flos.

There are no "rules" to lighting, but there are behaviors of different instruments which are good to know as guidelines. Once you know what each technology of lighting can and cannot do, it's easier to figure out what "cheats" you can get away with and which will get you fired. There are a lot of myths concerning fluorescent lighting based mainly upon the trusty old "cool white" tube which is so common and cheap in office interiors. While those lamps are pretty terrible (or great if you want the greenish look), there are a LOT of choices nowadays in terms of tubes of all sizes and colors. And Kino Flo isn't the only company making color matched tubes anymore. Most major tube manufacturers have been making triple phosphor tubes for quite some time now, and recently have adopted "film" color temperatures into their large production lines. If you're considering using inexpensive flo fixtures or even pre-existing fixtures, take some time to figure out which tubes you'd like to use, and read-up on their specs. And remember that if you're trying to get a fairly even color temperature between differing lighting technologies, you can use gels to bring SOME fluorescent tubes closer to daylight or halogen, OR you can go the other way and match your halogens to the existing fluorescent fixtures (because it's often a LOT easier if you're only bringing in a couple of halogens to just make them match the existing lamps). White balance can then make the overall picture "correct" once the lamps are relatively balanced.

With warm white professional fluorescents it's absolutely no problem. I'm using a mix of fluorescents and halogen in our studio all the time and it's perfect. There might be subtle differences in color temperature, even different brands of tubes have subtle differences (especially when dimmed down). But there are also subtle differences between halogen bulbs when one is at 100% and the other dimmed to 85%
All in all I can say the professional warm white tubes have a very nice, warm light that matches 3200K pretty much perfectly.

Very interesting. Thanks for clearing that up!

Does anyone know if there is some kind of chart that matches up one type to another? I.e., if you're using a 500w halogen, you'd need an ###w florescent at 3200k (or whatever)... Does such a thing exist, or is this just learned by experience only? (I have none, hence my idea of a "cheat-sheet").

Are you asking about light output? If so, you're typically dealing with a X4 difference. That is, a flo gives off 4X as much light per watt. So to give off as much light as a 500w tungsten, you need a flo of about 125w. Compact Fluorescents (CFL) are slightly less efficient and usually ring in at around 3X the output of the equivalent tungsten.

However, none of this matters regarding matching color temp. Color temp is color temp at any wattage (except when you're dimming). That is, you don't need the equivalent light output for lights to "match" in that sense.

Good luck.

~~Dave

If you're using 500w halogen tungsten pro fixtures, the color temperature will be 3200K and you can match up with 3200K flo tubes from several sources. If you're using 500w halogen worklights, those fall in the range of 2700K color temperature so you'll need a warmer flo tube to match up with that.

Not necessarily - I have a cheap 500W worklight that is definitely not 2700K. I don't know if it's 3200K exactly, but it's somewhere there (I guess between 3100 and 3300). That is with the standard bulb I bought it with.