The Fabulous and Often Misunderstood Fill Light

More than any other element of our lighting, the way we use fill light is what characterizes our individual lighting style. Despite this, the importance of fill light is often overlooked, or worse, it’s considered as a mere technical necessity.

While a keylight is vitally important in every lighting setup because it defines the angle and character of the highlights and shadows in a picture, it is the fill light that ultimately defines the tone and atmosphere of the picture by the way it modifies the depth and richness of those shadows.

(click thumbnail)The photo on the left is an example of key only, and the photo on the right is with the fill added. Photos by Chuck GlomanWhile our brethren who shoot on film have a much wider choice in the depth of their shadows, as cameras, transmission systems and viewers’ television sets become less susceptible to the introduction of noise along the signal path, the more room we have available to play with fill levels.


I am appalled to see that some film directors of photography continue to believe what they were told in 1950 about shooting film for screening on TV. Back then, when telecine chains were based on insensitive image orthicon tubes and analog production, and transmission chains did their very best to soften the images and introduce sparkly noise into the darker parts of the picture, someone put out the word to paranoid cinematographers that there should be no black in any frame and that key/fill ratios were to be kept as close to 1:1 as possible. The result of this advice was all those wonderful TV westerns where there was as much light under the brim of the cowboys’ hats as there was out on the open prairie. Then there were the sitcoms where there was no significant picture contrast, no matter the time of day or the location. In generations to come, historians will be drawn to conclude that it must have been severely overcast, indoors and out, day and night, throughout the second half of the twentieth century.

Meanwhile, those of us who work in electronic picture making were starting to take advantage of the improvements in pickup technology brought about by the more sensitive Plumbicon tubes and later CCDs. Together with digital processing that began inside the camera head and moved inexorably along the picture chain, we were slowly getting an imaging system that wasn’t afraid of the dark. While this gave us the opportunity to use plenty of contrast, with areas of darkness and deeper shadows on faces, I recall directors and designers willing to explore, but producers who worried that the drama looked too dramatic and might distract the audience.


The process of arriving at a tolerable compromise between what the medium can do and what the producer thinks the audience wants to see has been very fruitful. The subtle fill sources that had long been available to light film have at last been applied to shooting on video, although admittedly at lower key/fill ratios.

Unfortunately this newfound freedom not to fill came along at the point that the baby boomer anchors behind every desk in the in the known TV world decided that they wouldn’t move on to make way for the next generation. Instead, they have just stayed put in their chairs and aged less than gracefully, constantly demanding more fill light and softer light sources in the mistaken belief that obscuring the shadows brought on by gravity and decreasing skin elasticity, would somehow allow the aging process to pass unnoticed by gullible viewers.

I would like to propose a new law of lighting optics, henceforth to be known as the Inverse Fill Law: “The vertical angle of fill lighting is inversely proportional to the age and vanity of the talent.” Young, confident performers are perfectly happy with the 35-40 degree angle typical of talking-head portraiture. As the crow’s feet, multiple chins, laugh lines and under-eye bags appear, the performer, their agent or the producer, demand that the fill lights come down even lower, to reduce the shadows that define these additional features that arise from living a long life in the gravity field of a planet. Eventually, as the state of self-delusion reaches its final phase, fill light is demanded to be delivered from below the horizontal plane, thus transforming the performer into a horror show caricature of their former face, as the undersides of their eye sockets and chins now become their most prominent features.

Although fill light can come from any source (and I have certainly used big, bright HMI fresnel spots and naked quartz blondes and readheads as fill sources on many occasions), there is a well established convention of replicating nature by employing soft light sources.


Over the last couple of decades much attention has been focused on the development of soft, efficient and lightweight systems for producing naturalistic looking soft light. Effective source area is what makes a source produce the soft shadows that we need, and there is no shortcut technique available. Size really does matter. A source with a given area, whether it’s a bunch of fluorescent tubes in a KinoFlo Blanket light, a quartz halogen lamp inside a Chimera light box, a Mole Pup bouncing off a sheet of Styrofoam, an ancient Berkey Northlight, or an expensive array of LEDs, cannot be replicated by a smaller source. Each of these sources has different costs and benefits, but all of them can make beautiful pictures if used wisely and sparingly.

When I want to keep the shadows in a dramatic look from bumping into video black, my very favorite fill source is still a household bulb, wrapped in a cylinder of CT Blue gel, inside a white paper lampshade, of the kind you buy in import shops. The light is negligible in level, so soft as to be unidentifiable as a shadow source, but just lets the camera find a little detail in deep shadows.

Despite this, even in my most artistically delusional moments I have never been crazy enough to try this look in a game show or a sitcom. Your homework for this week is to see how far you can push the key/fill ratio of your pictures before being chastised by the vision controller or the producer.

Andy Ciddor has been involved in lighting for more than three decades as a practitioner, teacher and writer.