Turn Off Your Flash For Digital Images; Continuous Light Sources Make A Comeback
There's an old photographer's joke that goes: "If God invented light, then the devil invented fluorescent light." How times do change. With digital capture, fluorescent light can be your friend and I don't mean those long tubes hanging in lighting fixtures from the ceiling. I'm talking about a new breed of portrait lighting tools designed especially for digital photography. So what's the big deal and why is fluorescent a great source of lighting for digital imaging?
The RGB spikes of output from high-color fluorescent light closely match the
receptive RGB spikes of a CCD imaging chip. A CCD is least sensitive in its
blue channel and tungsten light has the least output in the blue, and when combined
with the effect of infrared output (mostly heat) it can overcome the chip's
entire spectral response. What about CMOS? It's difficult to generalize
a head-to-head comparison between CMOS and CCD image sensors, but assuming competent
engineering and optimum settings for white balance, exposure, and light levels,
image quality from CCD sensors should be similar to image quality from CMOS
sensors, at least in terms of color accuracy.
Comparing fluorescent continuous light sources to tungsten lighting is a lot easier. Fluorescent easily comes out the winner when compared to tungsten, which is 93 percent heat and 7 percent red light. Techies who want to delve deeper into light and color should visit Osram's Encyclopedia of Light (www.osram.com/service_corner/glossary/index.html).
What does this mean for digital photographers? It's simple: The light you used to hate, you can now love. Making all of this easy for us and wrapping these fluorescent lights in a useful package are a trio of digital lighting kits from three different manufacturers that can change the way you make portraits.
Westcott's Spiderlite TD5 is designed for still and video image-makers and works with either halogen or fluorescent lamps. The halogen lamps produce a consistent but hot 3200Þ Kelvin and the fluorescent lamps are rated at 5100Þ Kelvin, although that varies as the lights warm up. After using a color meter to set the exposure, I found my Canon EOS 20D produced better results in Auto White Balance mode. Your chip may vary...
The all-metal Spiderlite TD5 has a built-in speed ring for attaching a light bank and three separate switches that let you use multiple combinations of the lamps. A handle allows quick and easy rotation. The fluorescent lamps provide smooth, continuous light so that all of my exposures in this session were made in (gasp!) Program mode. I used the digital SLR's Exposure Compensation feature to increase exposure in 1/3 stop increments by looking at each image file's histogram on the camera's preview screen to make sure exposure was balanced.
Check Your Ego At The Door
From the mind of Gary Regester comes the Lowel Ego, a tabletop fluorescent soft light. Setup is a breeze: plug it in, place it on the table or light stand, and turn it on. The Ego comes with two 27w screw-in compact daylight fluorescent lamps that have a 5000-10,000 hour rating. Their Color Rendering Index (CRI) provides a more natural and realistic color balance than standard (color-me-green) fluorescent lamps. Lowel includes a hinge-folded white bounce card for reflected fill. It can be used for portraits but is also useful for making tabletop shots by eBayers, archivists, and desktop publishers. The Ego can also be used for webcam desktop video conferencing.
When using the Ego light as a main light for portraits, be sure to place the light as close as possible without getting it in the shot. Because of its small size, the Ego light is probably best suited to headshots and that's a good thing. I used to hate setting up lights for headshots; it took too much time fiddling to get the light looking like I wanted. The Ego sets up quickly and when used with a reflector, such as Westcott's Illuminator placed close to the subject on the other side of their face, makes an ideal headshot setup. I like doing headshots again and never thought that would happen!
I do a lot of shoots with new and inexperienced models. Big, complex light banks attached to electronic flash units distract from the mood I try to establish, so the Sunpak digitLITE 600, which is basically a cold "hot light," is a great setup for these kinds of portraits. The light is solidly built and easy to move around if your light stand has casters, and creates the kind of working environment that helps the model relax and be at her best. The digitLITE 600 uses cool fluorescent tubes that are balanced for daylight and do a good job of emulating the real thing.