Shooting With Studio Strobes (Electronic Flash Units)

Shooting With Studio Strobes (Electronic Flash Units)

by William Lulow

BENEFITS OF USING STUDIO STROBE UNITS

For the last sixty years or so, most studio photographers have used studio strobe units for their lighting needs. They are sometimes called electronic flash or studio flash, but they are basically  special flash tubes where an electric current is passed in a gaseous environment, usually the inert gas xenon. When an electronic current is produced, it causes the gas to glow very brightly and quickly, producing a “flash” of light. The “flash duration” is usually around 1/600th of a second. When used properly with flash “heads” placed in the correct places, they produce a very consistent, bright light that only goes off when the camera’s shutter is released. The really good ones are made of sturdy materials that will normally last a long time and be very dependable. (Much of my equipment is 30 years old and still working great!) The ones I have been using are Dynalite M1000 power packs and fan-cooled flash heads. (This equipment, unfortunately, is not manufactured any longer which is why I keep them in top shape):

This is the electronic flash generator that powers the heads.

Before the invention of these kinds of flash units, photographers used what were called “hot lights” which were always “on” and provided a good idea of what the image would look like on film. They were usually of the theatrical variety, large, power-consuming behemoths that were difficult to handle, often requiring more than standard household current and were exactly how they were described; hot! The photographer didn’t really need to “preview” his images because he could readily see what they would look like and that made lighting fairly easy. The light was always fairly bright.

When  studio strobe units were introduced in the mid-nineteen fifties, they were also large boxes capable of producing great quantities of light that lasted fractions of seconds. But the “heads” containing the flash tubes themselves were not difficult to handle or hot to the touch. One of the inventors of these lights was Harold Edgerton who, as the story goes, wanted to prove that all of a horse’s four hooves were actually off the ground at the same time during a gallop. He knew that he could not capture this motion with regular lighting equipment, so he set up a series of electronic flashes over a bit of a racecourse and each was triggered by the passing horse at a gallop. Sure enough, one of the frames showed that the hooves were indeed, off the ground at the same time. The flash had “frozen” the horse’s movement.

When I was starting as a photographer’s assistant back in the 1970s, one of my jobs was to watch a number of power packs to make sure they all fired when the photographer took the picture. I remember he had about eight packs all lined up in a kind of rolling cart he could move about the studio. He was shooting with 8×10″ view cameras (Deardorffs) so he needed very small lens apertures. Each of his eight packs was about 1200w/s giving him a total of about 9600 watt/seconds per exposure. If one of the packs didn’t flash, it could result in an underexposure of the film and potentially ruin the shot. Each pack was connected to a flash head mounted in a special array in a large softbox that he had made especially for his use.

Since then, photographers have been using electronic flash units in the studio as well as on location, to stop other types of action and to render their subjects sharp. But they often found it difficult to know exactly what their photographs would show with this type of lighting until Polaroid film was invented in the 1950s as well. With the adaptation of Polaroid film backs for view cameras and even 35mm ones later, photographers could now preview what their images looked like with electronic studio flash units.

Here is one of those Polaroid backs we used to use:

The advent of digital photography eliminated the need for Polaroid previews. Now, of course, the previews are instantaneous, but the digital age also did away with using much larger and bulkier cameras.

There are several other benefits to using studio flash. One very important one is that its light is so bright that it causes the subject’s pupils to contract, making the color of the person’s eye much more apparent. When hot light or plain room light is used, pupils would dilate in order for subjects to see in dimmer light. So if the mainlight was not bright enough, portraits would have basically black eyes where the color could not be seen. Here’s an example of what a bright mainlight can do, (these were made with a large, studio flash unit):

Here you can really see the subject’s eye color. Here’s another one:

The studio strobe light produced a much more powerful light, when used at normal portrait distances, than the sun’s rays. So, the sun could now be used as an extra accent light outdoors, with the strobe light used to illuminate the subject’s face. Here’s an example of that use:

Here the flash lights the subject’s face while the sun provides the accent on the hair and shoulders.

So, the really bright light produced in a fraction of a second with these studio strobe units makes an incredible difference in the quality of images the photographer can produce. The exceptionally short flash duration, as in Edgerton’s case, is able to freeze motion and allow photographers to use smaller apertures (f/stops) which increase depth-of-field and add a measure of sharpness to photographs.

DIGITAL TRENDS IN STUDIO FLASH

Studio photographers from the 1950s to the 1990s loved these studio flash units because they provided enough light to make exquisite images of their subjects from product shots to many great portraits and they had enough power to allow big, slow view cameras to be used with smaller apertures. Again, with the advent of really superior DIGITAL SENSORS for cameras made after 2000, say (which is when I actually made the switch to all digital imaging), film was not needed to produce professional quality photographs. Not only that, but because the digital sensors now used to record images were so sensitive to light, large amounts of power for flash heads were also not needed. Many photographers found themselves trying to use their big, powerful flash generators on their LOWEST POWER SETTING! In the past, a studio flash unit producing 1000 watt/seconds of power (a watt/second was the intensity of light produced in a one-second flash) would be necessary to shoot at a lens aperture of f/11 say in order to record maximum detail. Now, digital sensors could produce the same aperture with one-quarter of that power. So today, during my studio sessions, my flash generators are used mostly on their lowest power settings. For this reason, studio strobe lighting from MONOLIGHTS (flash heads with the generators built into them that can run on battery as well as electric power), have become more popular these days because they are not as powerful as the older units and are much more portable and easier to use with today’s digital sensors!

Here’s what the modern-day monolight is:

I have written about these before. The good thing about them is that since they are battery-powered, they have no power cords (you can use them if you like). They are much lighter than traditional heads and therefore easier to carry for location work. One drawback is that if they need repair, you have to send the whole thing in. But they are much less powerful because less power is needed today with digital sensors, as I mentioned.

The trends today are toward more portable units with less power output to get the same job done. I will be posting more on this subject in future blog articles.