is the ballast unit, which provides power for the head.
There are two speeds--on and off. You'll need to wait
about 15 minutes after turned on for the lights to stabilize,
and 20 minutes after turning the unit off before it can
be turned on again.
Since I use a scanning camera
back that actually moves a thin wand of pixels across the film plane,
I need a steady even form of lighting. I blew my entire budget on the
camera, computer, software, and monitor, so I didn't have a lot
of dough left over for a fancy lighting scheme. My first idea was that
I would use the 250w lamps in my flash heads, since that seemed like a
lot of light to me. I had used the modeling lights on a few jobs with
some tungsten film and got a decent exposure of f/16 at 11/2 sec. Guess
what--a scanning camera steps the CCD across the image, and my camera
can shoot an 8500 pixel wide image. Even a reasonable 3500x3500 pixel
image would require 3500 separate 1.5 sec exposures, for an unbearable
hour and a half scan. Even with the lens wide open I was looking at some
slow scans. Wide open I was looking at 13 minute scans, so I quickly torpedoed
While a 250w lamp is plenty for a modeling lamp, as a source of lighting
it was woefully inadequate. My camera maker informed me that with a good
light source I should expect 2-3 minute scans, rather than the painfully
long scans I was getting. I figured that it was back to the drawing board.
A quick trip to my local pro photo shop started my lighting education.
"You don't need bright tungsten lights," screamed my
salesman. "You've got to get HMI lights." HMI? What
in the world is HMI? He gave me a brochure from a California based movie
supplier, and I did a little homework. HMI lights are based around a metal
halide filament which must be excited by a ballast. The concept is similar
to high intensity Carbon Arc or fluorescent lights. HMI lights had a few
very interesting facts that made them perfect for the movie industry.
First of all, they were very close to perfect daylight-balance, often
ranging from 5200-5600K. This meant that heavy filtration was not needed,
which would rob a lot of light and cause inconsistent results. Secondly,
they ran very cool, reducing the heat on the set. This was a big plus
for the "talent" as well as for the accountants who paid the
electric bill. Last but not least, they punched out a boatload of light.
"Don't be surprised," my photo shop pal warned me, "if
a 575w HMI blows away a 2000w tungsten light."
Since I couldn't afford HMIs, I bought some 600, 1000, and 2000w
tungsten lights. With 10,000w of tungsten, I figured that I was all set.
Well, a scanning camera back is a demanding beast, and the best I could
muster in most situations was an f/stop of f/11 and a total exposure that
lasted almost eight minutes. Stopping the lens down to get some decent
depth of field gave me unbearably long scans, and shorter scan times required
horribly thin depth of field or software curves that created too much
image noise. It started to dawn on me that maybe I should try HMI lighting.
Last year I got my first taste of HMI lighting when I reviewed the spectacular
Briese line of lighting from Germany. While the 1200w Briese HMI blew
me away, so did its price, nearly $7000. I looked at excellent systems
from Profoto and Broncolor, but they too ran into the thousands of dollars.
After I had the Briese gear in my studio, my tungsten lighting has been
like a poor cousin. Not only is it hot, inefficient, and hot, (did I mention
hot?) the wall voltage in my studio varies just a little bit during most
scans. This required that I invest in three very large voltage stabilizers
that would nail my power down to 110v with hardly any variance. A recent
catalog of fine jewelry was extremely difficult since the brutally hot
tungsten lighting had to be brought in very close to the jewelry. The
hot movie lights actually overheated my camera and blew out a circuit
board. Since I don't often do these kinds of macro shots with the
digital camera, I hope this won't be an issue again, but the heat
issue is a real one.
Recently I heard that a company called Britek was planning to bring out
a very affordable HMI lighting system called Dayphoto. A quick flip through
the pages of Shutterbug reminded me who Britek was. You know those little
AC powered slave flashes that screw into a normal light socket? Well,
Britek has made a living with those flashes, as well as a catalog full
of reasonably priced lights and lighting accessories. An assistant reminded
me that I actually owned some Britek lights, their small AC powered 200
ws studio lights, which we sometimes took out on location as emergency
back-up units. After years of travel they all still worked like new. (In
fact a few assistants shot their portfolios with those flash units.) While
I had my doubts about a solidly pro-oriented piece of equipment from Britek,
I arranged to get a few evaluation units.
When the lights arrived, I have to say that I was pleasantly surprised.
While there were the telltale signs that this was equipment designed and
manufactured in Taiwan rather than Stuttgart, like misspelled words on
the warning labels ("Lighting Systen" and "USA Authrized")
and a poorly designed clamping system, this was clearly a substantial
piece of equipment. Britek sent along a 200w and a 500w unit. Since I
am used to HMI lights based around the European standard Osram bulbs,
which are 575 and 1200w, wattage ratings of 200 and 500 were news to me.
A quick peek under the hood confused me even more. The 500w unit was loaded
with an Osram 400w HMI bulb, the 250 with a Japanese 200w bulb. Curious.
Britek claims that the unit's light output in lumens correspond
to 250 and 500w units, but they sure looked like 400 and 200w bulbs to
Wattage clarifications aside, both units really looked well put together.
Each lamphead has an integral reflector, clear heat absorbing front glass,
and a standard cine style clamp accessory system. The large unit had the
same 81/2" diameter accessory mounting system as one of my other
units, so Chimera light boxes fit on beautifully. The heads are molded
of sturdy black polycarbonate with a somewhat awkward steel mounting clamp.
Heavy cables and rock solid locking electrical connectors inspire confidence.
The whole effect is of a thoroughly professional unit, in spite of the
tacky yellow labeling.
The ballast units are actually quite neat looking. A molded yellow central
section and charcoal colored end caps give the units a vaguely European
look, and the molded carrying handle is practically indestructible. There
are indicator lamps for main power and lamp start as well as a main power
switch. There is a definite procedure to start up an HMI, and without
the right procedure you can ruin the bulb. While my early production units
had no Owners Manuals, I had been around the block with HMI lighting before,
so I soldiered on.
With the head cable screwed into the ballast, the next step was to power
up. I turned the switch on the lamphead to the "on" position,
then fired up the main power. True to form the bulb sputtered to life,
then began its 15 minute process of "warming up." Once the
bulb is fully warmed, it should yield perfectly stabilized lighting for
the life of the bulb, which in this case is around 500 hours. I hung a
medium Chimera softbox on the 500w unit and used the 250w unit direct.
After a few test scans I realized that this was a magnetic ballast unit,
not an electronic ballast one. Electronic ballast units allow the lamp
to be dimmed, usually allow hot restrike capability, and are completely
flicker-free. The less expensive magnetic ballast units won't allow
a hot restart (if you shut the unit off you must wait the 15 minutes for
it to cool before restarting the ballast), won't allow any light
attenuation, and most importantly flickers at the rate of the incoming
power. This means that the output of the light is cycling at 60 beats
per sec. While this has no bearing on still photography with film, for
movies, video, and digital scanning cameras this can be a factor. I found
that "line times" of 1/80 of a sec or slower did create a
noticeable flicker in the images, but everything greater than that looked
great. I would have liked to have seen an electronic ballast version for
comparison sake, since sometimes you just need a fast scan, which is practically
impossible with a magnetic ballast HMI.
Once I had an exposure dialed in, I shot a few digital images, and I have
to say that these lights performed beautifully. While the color temperature
of the 2500 is spot on, the 5000 needed a bit of filtration. I added a
very thin red filter on the 5000, which brought the color temp back to
5600K. After 10 or 12 exposures I realized that something was different
in the studio--it was a lot cooler. The HMIs ran about as cool as a high
output fluorescent. Even after several hours the props in my tabletop
setup were cool to the touch. Better even than the cool running was the
phenomenal efficiency. Just like the expensive Briese lighting, the affordable
Briteks annihilated tungsten lighting as far as exposure times. While
a daylight filtered 1000w tungsten lamp required an overall exposure of
1/4 of a sec at f/16 with my scanning back, the Britek Dayphoto 5000 required
only 1/60 of a sec. Yes, that's four f/stops. Since the rule of
thumb is that HMIs produce 4-8 times as much light as halogen or tungsten
lighting, the Britek was right in the ballpark.
Since the HMI light output is already very close to daylight, there are
very little hardware or software corrections necessary. This creates very
clean scans with remarkably little dark noise. True to form, the Britek
Dayphoto lights were absolutely perfectly regulated. Even 149MB scans
of gray seamless paper revealed absolutely no dark stripes or banding.
A most impressive performance, and one that requires $1000 regulators
on my 2000w tungstens.
Even when used for traditional photography these HMI lights shine. While
hot lights require heavy blue filtration or tungsten-balanced film to
balance with daylight, HMI lights are almost exactly daylight-balanced.
Photographers who like to blend daylight with studio lighting might consider
this is a dream system. (Though I wouldn't mind adding an 81B filter
for daylight-balanced transparency film.)
While there are certainly better engineered and constructed HMI lighting
systems out there, they are many thousands of dollars more than the Britek
Dayphoto system. With a direct price of only $795 for the 500w ballast,
lamphead, HMI bulb, light stand, softbox, filter frame, and heavy-duty
barn doors, you can't touch this value. The 2500 is only $588.95,
and includes the same kit. Britek also will be offering a 200w unit which
should compare favorably to 600w tungsten lighting at only $449.95. Britek
says that they are working on a super high output 1200w unit as well,
and electronic ballast units may be on the horizon, also. (At slightly
higher prices of course.) While I have serious reservations about the
flicker of these lights for scanning camera usage, the other benefits
and the great price makes them really attractive.
Whether you shoot film, video, or digital, HMI lights have a lot of benefits.
Having seen the beautiful light quality of expensive units like Briese,
Profoto, Broncolor, and K5600, I have longed for HMI lights of my own.
The Britek Dayphoto lighting system is an answer to a lot of digital photographer's
prayers. For the studio photographer, this gear looks heavy-duty and rugged
enough, and you sure can't beat the price.
For more information contact Britek, 12704 Marquardt Ave., Santa Fe Springs,
CA 90670; (800) 925-6258; (562) 404-0593; (562) 404-0852.