AudioMedia - January 2009 - (Page 60)

video guide A Sound Pro’s Guide To Video Light & Lighting – Part One Every good Director of Photography knows that lighting is everything in a picture. KEVIN HILTON puts the spotlight on the tricks of HMI and LEDs, and even the physics behind the floodlights. T he art of cinematography involves a great deal of equipment and technology that has grown in sophistication over the years. Despite that, just about every Director of Photography will tell you that the job comes down to manipulating the lighting. Hardly surprising, then, that an outstanding cinematographer of the s and ‘ s, John Alton, called his book on the subject Painting with Light. Alton did that with black and white for the film noir The Big Combo ( ), and in colour on An American in Paris ( ), sharing the best colour photography Oscar with Alfred Gilks. The English DP Douglas Slocombe, who shot the first three Indiana Jones films, many Ealing Studios films, and the original The Italian ), says a good photographer observes Job ( how light works in a space, and does not rely heavily on technique or think just in terms of footcandles (see glossary). Classically I nspired Picking out people and objects in light on a darker background is something that was perfected by artists like Rembrandt – his Night Watch is an outstanding example of this – and stills photographers and cinematographers do much the same thing with lenses, film stocks (and video and now data media) and lamps. This two-part examination of light and lighting will look at the basic types of lamp, how they are used, and the latest advances in technology. But an understanding of the nature of light and what it can do is as important as knowing about floodlights, keylights, HMI, and LEDs. So, a quick trip back to basic school physics. Visible light comprises electromagnetic waves that travel at , miles a second (approximately million metres a second). Radiant energy is produced by natural and man-made sources, among them the sun, electric lamps and radioactive ore, and travels in space as electromagnetic radiation. The visible light spectrum is usually considered to be wavelengths between , and , AU (Angström Unit, equal to a ten millionth part of a millimetre). The components of this spectrum are revealed when white light is split by focusing it through a prism or, more romantically, when water vapour in the upper atmosphere does much the same and forms a rainbow. The ability of humans to process and quantify the light in any situation is a balance between the somewhat imperfect nature of the eye as a receiving device, and the ability of the brain to correct and interpret the information it receives. This means that judging any amount of light in a scene is a mix of subjectivity – what we think we are seeing – and objectivity – the reality of what is there to begin with. So much of working with light is comparative and depends on the situation: a pocket torch will light up a dark space, but in daylight it will appear very weak indeed. GLOSSARY Footcandles, Lumens, Lux All three are measurements used in lighting, although many cinematographers work instinctively rather than relying overly on meters and constant adjustment. The lumen measures luminous flux, that is the rate of luminous energy. Each lumen unit is equal to the quantity of light per second from a point that is producing one candlepower of intensity in a unit solid angle (in other words, an angle created at the vertex of a cone). Light from an electric bulb can be determined in lumens per watt. The candle was replaced as the international System of Units (SI) measurement of luminous intensity by the candela. A candela is defined as the luminous intensity, in a given direction, of a source emitting monochromatic radiation of a power of x Hz, with a radiant intensity of in that direction of / watt a steradian (SI unit of solid angle). Lux is the international metrical measure of the intensity of illumination, being equal to one lumen hitting a surface of one square metre at a perpendicular angle. A footcandle is the more common term of measurement in cinematography, being the intensity of luminosity produced by a standard candle on the surface of a one-foot radius sphere one foot away. The footcandle measures direct incident light illuminating a subject from external sources. One footcandle equals one lumen per square foot, while the lux is similar to the footcandle, only in millimetres; . lux equals one footcandle. A S ense O f Light The eye does not distinguish variations in light levels as they are in reality, the scientific reason being that its response is logarithmic and so a light meter should be used for accuracy, something many old school cinematographers would scoff at. Still, those working with light need to be aware of the three primary sources: incident light, the strength of light hitting a subject; surface brightness, the amount of light reflected from areas of a scene; and integrated light, which is the average amount of reflected light that reaches the camera. Talking about light can be done in general, non-specific terms, such as ‘warm’ or ‘cold’, but only gets over a sense of what is meant. Despite the compromise of the human eye-brain method of processing light, it is much more selective in recognising light intensity and colour than a camera. Artificial lighting is needed when filming a scene, whether outdoors or inside a building, because natural and standard domestic light are much more suited to the human eye. Which is why most stunning sunsets and landscapes tend to look disappointing in photographs, and ordinary house lights are not suitable for film or TV work, unless the production is a documentary or socio-political realist drama. So, some form of more powerful, additional lighting is added to make a scene look like it should on screen. Above that light can be added and manipulated for artistic and dramatic effect; think of the over-blown Technicolor of References On Camera by Harris Watts, BBC Books Dictionary of Cinematography and Sound Recording by Wallace S Sharps, Fountain The Complete Film Dictionary by Ira Konigsberg, Bloomsbury Lighting for Television and Film by Gerald Millerson, Focal Press Interview with Douglas Slocombe by Kevin Hilton, British Cinematographer magazine 60 AUDIO MEDIA JANUARY 2009

Table of Contents Feed for the Digital Edition of AudioMedia - January 2009

AudioMedia - January 2009 Contents Recording News Post News Broadcast News Geo Focus: India What's Up UK? Special Report: Pimp My Ride AKG C214 Sony Acid Pro 7.0 Final Cut: Mirror's Edge Opportunities in the Reality World She's Got the Look The X-Factor Sadie LRX2 Source Elements Source-Connect 3.1 Buying a Recorder In Control Product Sampler: Trade Shows Video Guide AMSR News Digico SD8 The Last Picture Show File Server

AudioMedia - January 2009

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.