Light sources visible in frame originating from the scene — lamps, neon, candles, streetlights. Real props that double as lighting instead of hidden fixtures.
On set, lamps, neon signs, and candles aren't just there for decoration — they are your light sources. Practical lights work directly within the scene, visible in the frame, and actively contribute to the illumination. While the electrical crew works around them with spotlights, HMIs, and softboxes, you utilize what's already hanging or standing in the location. A desk lamp, the neon sign above the bar, the streetlamp outside — all of these are practical light sources that appear authentic and illuminate functionally at the same time.
The craft challenge: Practical lights are notoriously weak and often have undesirable color temperatures. A standard incandescent bulb in a bedside lamp provides hardly any lux on faces, and its color is frequently yellow-orange. You therefore have to enhance it — by filling from the outside, using reflectors, or with a weaker backlight from behind that makes the source appear stronger visually. At the same time, you must not overdo it, otherwise you'll destroy the authenticity. The trick is to accept the existing light and skillfully supplement it, not replace it.
In practice, this often happens: The production designer and location managers show you an apartment with terrible ceiling lights and a single floor lamp. You immediately turn to the electrical crew and ask for a correction behind the lamp, maybe a small Fresnel, or you ask if the bulb can be swapped — for a higher-quality model with a better color index. It often makes sense to bring light in from outside through the windows at night, while you treat the interior practicals as focal points.
The interplay between practical lights and technical lighting strongly defines the look of modern feature films. Rooms appear lived-in, not theatrically lit — provided the balance is right. Ensure that practicals burn consistently even during longer takes, especially if they are meant to follow movement or bridge cuts. A flickering fluorescent tube can work wonders or ruin the entire shoot.