pincushion distortion on long-focus lenses of telephoto configuration. Every lens manufacturer sets its own minimum image quality acceptance standards. Higher prices often mean stricter quality control, so to satisfy the critical demands likely to be made of you, it is sensible not to economize in this area. SPECIALIST HARDWARE FOR IMAGE CAPTURE PROFESSIONAL INTERIOR PHOTOGRAPHY 30 3 RECORDING MEDIUMS: FILM VERSUS DIGITAL The era of high quality digital imaging has now well and truly dawned and digital imaging has become the mainstream alternative to film and, in some areas, the dominant alternative. It is an area that all practicing photographers will be addressing seriously, if they have not already done so. The aim of this chapter is to clarify and lay bare the facts of traditional silver halide photography in comparison with those of modern digital technology. Both film and digital image capture share many common characteristics. Both record light reflections received at the image plane onto a light-sensitive medium, with the objective of reproduction at some later stage. While the eventual output can appear very similar, the routes to achieve it are technologically quite different. The silver halide technology of traditional photography produces an analogue, con- tinuous tone image where quality is limited by the grain size of the individual halide crystals. Digital images, by compar- ison, are electronically created, stepped-tone images based on the binary digital system where ‘0’ is black and ‘1’ is white, in its simplest form. An image is recorded as a framework of millions of ‘pixels’: the smallest distinct units, or picture elements, of a digital image that are encoded with the varying intensities of the colours red, green and blue that make up the image. Being well versed in the practical aspects of film technology, as most of us are, this section will feature Ashley Morrison, a photographer with several years practical experi- ence of shooting interiors digitally. He runs an extremely successful business, working for interior magazines, top companies, advertising agencies and design groups. Ninety- nine per cent of his work is shot digitally and he has no regrets over making the transition from film-based photography. PROFESSIONAL INTERIOR PHOTOGRAPHY 31 Ashley Morrison Ashley Morrison runs AMP Studios with two associates in the beautiful countryside of Northern Ireland. Three-quarters of his work is shot on location and much of this is interiors work for the magazine and commercial markets. Until two years ago, most of his work was shot on a medium-format Hasselblad system using conventional film. Jumping in at the deep end, Ashley was the first UK photographer to buy the MegaVision T32, a three-shot area array back using the Philips 2k × 3k chip. The chip is rated at ISO 32 and an exposure is made through each of the RGB filters in turn, taking about 8 seconds. While designed primarily as a medium- and large-format studio back, the T32 can also be converted to a portable digital camera using an adaptor plate and 35 mm SLR lenses. This goes some way to overcoming the problem of wide-angle digital photog- raphy resulting from the small size of the chip (the size of a 35 mm film frame) relative to the covering power of lenses designed for medium and large formats. For interior location work, Ashley found that a Nikon 18 mm lens on the T32 actually gave him a wider field of view than the 40 mm lens on the Hasselblad. A degree of shift could also be employed using the Nikon 28 mm and 35 mm shift lenses. Two years on and the T32 is now studio bound, sitting on a 5 in × 4 in Horseman, and largely used for pack shots. Ashley found the three-shot system good in quality but RECORDING MEDIUMS: FILM VERSUS DIGITAL PROFESSIONAL INTERIOR PHOTOGRAPHY 32 Figure 3.1 Ashley Morrison, digital interior photographer (photo copyright: AMP Studios) difficult and frustrating to work with on location: nothing must move between exposures (not even trees blowing in the wind outside the window) and the natural light must remain constant. If the sun went behind the clouds between the three exposures, he had to start again. For his location work, the T32 has been replaced by the Phase One H20: a single capture digital back that creates high quality 48 Mb files from its 16 megapixel Kodak chip (36.9 mm × 36.9 mm in size). Rated at ISO 100 it can cope with long exposures of up to 16 seconds if required, producing massive files that can ‘give a 5 in × 4 in tranny a good run for its money’. The H20 back is connected to a G3/500 PowerBook laptop computer with an internal CD writer, which enables the client to go away with all the images on CD at the end of the shoot if required. Under less rushed circumstances, Ashley prefers to view the images on the 21-inch screen back at the studio for fine adjustments in Photoshop before handing over the images. A big bonus with digital, Ashley finds, is in the lighting. First, he can make white-balance adjustments to eliminate colour casts from artificial light sources, completely doing away with the need for a colour meter and any colour RECORDING MEDIUMS: FILM VERSUS DIGITAL Figure 3.2 Ashley Morrison working on location with the Phase One H20 digital back connected to a laptop computer (photo copyright: AMP Studios) correction or compensation filters. Second, to overcome the problem of lighting difficult areas, he can shoot a series of shots, lighting each area separately and bringing them together in Photoshop. Being careful not to move the camera, change the aperture or point of focus, he can adjust exposure for different parts of the image by changing the shutter speed. He can even place lights in the middle of the frame if necessary, so long as he has taken a shot with the light out of frame on a different exposure. A copy and paste operation in Photoshop stitches the separate elements back into a coherent whole. Despite the smaller image area of the CCD chip (than the 6 cm × 6 cm format of roll film), Ashley and his colleagues find that the standard Hasselblad lenses (the widest being the 40 mm) give sufficiently good coverage 95 per cent of the time. For the other 5 per cent he uses a Horseman DigiFlex II, which is effectively a 35 mm SLR camera body exclusively designed to take high-end digital backs and Nikon F-mount lenses, thereby making full use of the covering power of the wide-angle lenses available. With the DigiFlex II, Ashley uses a series of 35 mm SLR Nikon lenses, ranging from the widest at 18 mm to the 35 mm shift lens. The 28 mm shift lens yields excellent results, and is often used when joining two or more images together. In common with most interior and architectural photog- raphers, Ashley believes in maintaining the verticality of the camera back to avoid the problem of diverging verticals from pointing the camera down slightly. If, however, the camera has to be tilted, he would correct it later in Photoshop using the ‘skew’ tool. Finally, what Ashley sees as possibly the biggest advan- tage of digital over film is that he gets to see exactly what he has shot in a matter of seconds after exposing the image: no more guesswork or reliance on Polaroids! He supplies the client with CMYK or RGB files, along with ‘proof’ or ‘match’ inkjet prints. A summary of the equipment that Ashley currently uses is listed below: Location system. ᭿ Cameras: ᭿ two Hasselblad 553s and a 503 body with 40, 50, 60, 80, 120, 150 and 250 mm CFi lenses; ᭿ Horseman DigiFlex II with 18, 24, 28 shift, 35 shift, 50, 55 macro, 85, 135 mm Nikon manual lenses; RECORDING MEDIUMS: FILM VERSUS DIGITAL PROFESSIONAL INTERIOR PHOTOGRAPHY 34 Figure 3.3 (facing page) A fine example of digital work by Ashley Morrison with the Phase One H20. Notice the sharp detail throughout the full depth of the image (photo copyright: AMP Studios) . has no regrets over making the transition from film-based photography. PROFESSIONAL INTERIOR PHOTOGRAPHY 31 Ashley Morrison Ashley Morrison runs AMP Studios. but RECORDING MEDIUMS: FILM VERSUS DIGITAL PROFESSIONAL INTERIOR PHOTOGRAPHY 32 Figure 3.1 Ashley Morrison, digital interior photographer (photo copyright: AMP