Cinematography-Theory-And-Practice

night, or if heavy clouds move in during the shot. This can be controlledwith a timing device, or it may be necessary to stand by anddo exposure changes manually. If you don’t want the depth-of-fieldto change during the shot, you may want to add or subtract NDfilters or alter the shutter setting. Also, with long intervals betweenexposures, it is possible for enough light to leak around the normalcamera shutter to fog frames. An additional shutter, known as a cappingshutter, is added to prevent this. Capping shutters are availablefrom the same places that supply intervalometers. The Steele Chart byLance Steel Rieck (Table 16.6) shows screen time versus event durationfor time-lapse photography.Figure 16.17. An on-the-set lightingeffect (called a gag) such as this willoften be executed by the lightingdepartment. This one, a glowing ballof light for The Sorcerer’s Apprentice,was designed by Michael Gallart andexecuted by the legendary Billmo.It consists of a three-faced clusterof LEDs powered from a 12 volt DCsource, run through an LED dimmer.It is shown in use in Figure 16.18.TIME SLICINGThis is the effect that was popularized in a series of Gap ads and mostfamously in the film The Matrix. This is the effect where a characteris suddenly frozen but the camera dollies around the figure or theobject. This effect is accomplished with an array of 35mm still camerasarranged around the subject. A regular film camera is part ofthe array. At the moment of freezing the action, the entire circle ofstill cameras is fired. These still photos are then scanned and blendedtogether to form a film shot (Figure 16.1).Visualize it this way: imagine a film camera on a mount that canbe dollied around the subject instantaneously, let’s say 90°, with thefilm running at very high speed. Since the dolly is instant, it “sees”the subject from all points around that arc before the subject canmove. This is what the still cameras do: they see the subject fromas many points of view as you wish — all at the same time. In practice,the subject is often placed on greenscreen and then the greenbackground is replaced with live-action footage of the original scene,usually matching the dolly action simulated by the still array. Theresult is a dolly around a live action scene with a frozen subject inthe middle. The still cameras can be arranged in any type of moveimaginable; the effect is not restricted to a dolly around.technical issues327