Chris,
HID is just plain cool. I was extremely curious about arc lamps when I
was a kid. Still am. Too bad Xe short arc isn't efficient, because it
sure is neato! Metal halide HID will have to do. But the new little HID
lamps for portable and line powered use are really cool. Just need more
time to proliferate.
I use metal halide in the lab for high speed videography and general
camera work. We also have some medical surplus Cermax lamps (ACMI 300
watt illuminator for endoscopy, about 300$ used in working order.) We
have both the mastercolor and
the locally made (Solon is 25 minutes away) Venture HMIs as well as Ge
and Sylvania. I'm quite happy with with Venture's normal slightly
bluish daylight mix as a room light. Yeah the mastercolor's warm white
rocks, but the Venture mix in their smaller lamps is very consistant
in color. We also have the Sylvania 75 watt MHIs, And GE up to like
1000 watts. Our buiilding is lite with Halide in the public spaces and
flourescent in the labs. So I have quite a few to choose from in the
lamp cage. The table lamp you mentioned before is a Venture lamp. The
68 watt 28$ DC based lamp is actually quite a nice color balence for
in the home, even though its missing the dramatic orange red, it does
have some energy in that area.
At work I'm shooting images of up to 3 kilometers of 300-1000 nm
polymer fiber hanging in a 10 cm space, (we do electrospun nanofibers)
so we need to throw as much light as possible to film things, from a
non point source if possible. In the lab we of course run switching
ballasts as we film at 2000 frames/sec straight to hard drive, but even
the 150 watt theatrical lamp will come up on a 175 watt ballast. So we
aim a nice collimated beam at the spin assembly and look at the light
diffracted away from the fiber using a masking setup. Not wanting to
use condenser lenses because of loss, we use wide metal halide tubes.
We've also bought some of the smaller capsuled lamps such as
Mastercolor and the M175 mentioned below because of their higher energy
density.
Having that nice rich healthy spectrum at work, I of course let it
migrate
I've bought a small Mastercolor double ended lamp and ran it off a
stock ballast for use as a home work light in the garage, it rocks.
I've also bought a small 175 watt Sylvania (M175/U/MED/ED17) for
home use, its great in the basement lab if you diffuse it properly with
sandblasted glass.
Ones I'm not happy with for home use are the 150 HTI watt short arc
theatrical HMI, it has arc wander/flicker problems, and the Welch
Alleyn 35 watt in the reflector makes a great bike light but the
unvaporised fill metal wanders around inside the lamp making it
annoying as a reading/work light. The Welch Allen in its intended role
as a fiber pump is a great piece of technology.
In the lab we of course run switching ballasts as we film at 2000
frames/sec straight to hard drive, but even the theatrical lamp will
come up on a 175 watt ballast.
Once you find a good source of ceramic sockets, migrating these lamps
to home use is quite painless, Watch out for the UV though, even though
the adsorbing glass is manditory in the lamp envelope, there is a small
residual amount.
Steve Roberts
