Re: quartz halogon

Tom Ferguson (tomf2468@pipeline.com)
Mon, 19 Jan 1998 20:43:40 -0800

"S. Carl King" <sanking@hubcap.clemson.edu> wrote:
>>I purchased a Regent brand stand of two 500 watt quartz halogon floods at
>>a home building supply store. The whole things comes on a stand and nice
>>telescoping tripod for only $30. Does anyone know the color temperature of
>>quartz halogon lights and what color compensating filter is needed for
>>color work. This would be one great deal for photographic lighting, if one
>>can stand the heat.
>>
Mac Legrandi <fontpro@usa.net> wrote:
>A while back some one mentioned buying 5600K daylight T3 bulbs for these
>inexpensive lights. I've checked with Home Depot and they have no idea.
>Where can we buy these? Who manufactures them?

I do about 90% of my personal work with hot lights (and even a bit of my
"commercial" work). I too bought "Home Depot" lights as early experiments.
All common quartz halogen lamps are ABOUT 3200K on the color scale. That
means that if you shoot with "Tungsten" color film you SHOULDN'T need any
compensation filters. Kodak EPY is great for transparencies. If you want
(need) to shot "daylight" balance film, you SHOULD only need an 80A filter
either over the lights or the camera lens. This is a blue filter, and will
cost you 2-1/3 stops of light! Black and White film really doesn't care
(some B&W films may have a 1/3 stop slower EI with quartz/tungsten light).

Note the above uppercase words. "Home Depot" or other cheap (construction
work) type quartz lights are only roughly color matched. The companies
making these really don't care if they are 3200K or 2900K or 3500K. Mine
were a bit "warm" (yellow/orange).

The second limitation with these lamps is the lack of "modifiers". You
will soon long for barn doors, snoots, umbrella mounts, etc.

I have never found "daylight balanced" 5600K lamps for quartz lamps. The
better "professional" grade companies all sell glass 80A filters to fit
their housings (but as mentioned, they cost a lot of light output).

The "Home Depot" type lamps are a great way to learn how to work with hot
lights. Have fun with them. Just don't put too much money into them, you
will most likely outgrow them. Mine now live in the garage (they are great
for working on the car), the studio has a set of "Omni" lamps.

tomf2468@pipeline.com (Tom Ferguson)