Dancing Shadows
Michael
Award: Top 100
School: uwcsea
Teacher: michael h zhang
Category: Contrived
Photo #21502
Dancing Shadows
This photograph captures dancers mid-performance using a half-second exposure (1/2 s) at f/22 and low ISO (~100) on a 70 mm lens. Each setting was chosen to utilise a specific physical principle: the narrow aperture and low ISO minimised light intake, allowing for long exposure without overexposing the shot.
During the half-second the shutter remained open, the CMOS sensor recorded photons from every position each dancer occupied. Because the dancers moved during the exposure, light from their previous positions was integrated onto the same frame, going through a process called temporal integration. The result is a series of half-translucent, overlapping figures that trace each dancer's path on the stage. Where a dancer paused, more photons struck the same cluster of pixels, producing a brighter, sharper region. Where movement was fast, photons spread across a wider area, creating ghostlike streaks. Therefore, the varying sharpness across the frame acts as a map of each dancer's velocity during the exposure interval.
Two dominant stage light sources, one emitting cool cyan light and one emitting warm amber light, illuminate the dancers from different angles. As the dancers crossed through both beams, the sensor recorded light from both wavelengths on overlapping pixel locations. This produces additive colour mixing: regions lit by both sources will show mixed colours, distinct from the pure cyan or amber where only one source dominates.
The stage floor reflected the light trails at equal angles of incidence and reflection, creating the effect of motion below the dancers.
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