English: The spectra of various light sources as revealed in a reflection diffraction-grating. Clockwise from the upper left: Fluorescent lamp, incandescent bulb, candle flame, and white LED lighting.

The helical, cool-white fluorescent-lamp produces a variety of spectral lines which are shown in the actual reflection of the lamp, running down the center. The incandescent bulb produces spectra indicative of a blackbody radiator. This is very similar to the candle flame, with the exception of the candle's strong line in the yellow (from the carbon). The LED lighting consists of a mixture of red, green and blue. Unlike single source-point lamps, the LED lighting contains multiple light-emitting diodes, producing many streaks of color on the grating.

To photograph all colors in a single frame, the angular size of the light source needed to be very small, requiring that the camera be very close to the grating while the light source was rather far away. The closeness of the camera's convex lens to the grating produced the colorful, curved streaks to either side of the light source.