created bright highlights (rim lighting) along the edges of her body, separat-
ing her from the background. In this case, the lights themselves also formed
a compositional element in the background.
With a weaker (or nonexistent) front or side light, backlighting can also
allowyoutocreatesilhouette(orsemi-silhouette)effects.Experimentingwith
this technique you can achieve some amazing photographs. In the series of
photographs on the facing page (images2-9,2-10,2-11), I focused on the
model. Her body shielded my lens, and I had her move slightly to my left so
the sun would just break past her body. I varied the output of my flash for
each photograph, achieving a variety of different exposure and results. Who
is to say which exposure is correct?Light and Color.
Color Temperature.When we look at a visible light source, it appears to be
white, but it’s actually a mixture of colors that our eyes are designed to per-
ceive as white. In fact, few light sources are actually neutral in their color.
Most have some some color cast. This color is measured in degrees Kelvin
(K). As a result, it is known as the color temperature. The higher the tem-
perature, the more bluish the light is; the lower the temperature, the more
reddish the light is. As shown in the table below, light sources have many dif-
ferent color temperatures.Overcast daylight.................. .6500–7200K
Midday sun...................... .5400–5700K
Sunrise or sunset.................. .2000–3000K
Fluorescent (daylight-balanced)............ .6500K
Electronic flash.................... .5600–6200K
Fluorescent (cool white).................. .4300K
Tungsten-halogen...................... .3200K
Household lamps (40–150W)......... .2500–2900K
Candle flame.......................... .2000KColor temperature has a direct bearing on how colors will be recorded in
your images. In many cases, getting the desired image colors requires com-
pensating for the color of the light source. This is most commonly accom-
plished through film selection, filtration, or white-balance selection.
Daylight films render colors accurately, as your eye sees them, when used
under light with a color temperature of 5500K (the light found in the mid-
dle of the day). Later in the day (say, at the “golden hour” discussed on page
34), the color temperature is lower. Shooting with daylight film, this will re-
sult in colors that are warmer than they appeared to your eye. To correct for
this, you would need to add a color-compensating filter to your camera.THE PHYSICS OF LIGHT 39Few light sources are
actually neutral in their
color. Most have some
some color cast.