Konica Minolta SLR manual Introduction, Bister, Faranak Morderai and R. M. Aveling

Journal of Orthodontics, Vol. 33, 2006, 000–000

FEATURES SECTION

Comparison of 10 digital SLR cameras for orthodontic photography

D. Bister, Faranak Morderai and R. M. Aveling

Department of Orthodontics, Guy’s Hospital, London, UK

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Digital photography is now widely used to document orthodontic patients. High quality intra-oral photography depends on a satisfactory ‘depth of field’ focus and good illumination. Automatic ‘through the lens’ (TTL) metering is ideal to achieve both the above aims. Ten current digital single lens reflex (SLR) cameras were tested for use in intra- and extra-oral photography as used in orthodontics. The manufacturers’ recommended macro-lens and macro-flash were used with each camera. Handling characteristics, color-reproducibility, quality of the viewfinder and flash recharge time were investigated. No camera took acceptable images in factory default setting or ‘automatic’ mode: this mode was not present for some cameras (Nikon, Fujifilm); led to overexposure (Olympus) or poor depth of field (Canon, Konica-Minolta, Pentax), particularly for intra-oral views. Once adjusted, only Olympus cameras were able to take intra- and extra-oral photographs without the need to change settings, and were therefore the easiest to use. All other cameras needed adjustments of aperture (Canon, Konica-Minolta, Pentax), or aperture and flash (Fujifilm, Nikon), making the latter the most complex to use. However, all cameras produced high quality intra- and extra-oral images, once appropriately adjusted. The resolution of the images is more than satisfactory for all cameras. There were significant differences relating to the quality of color reproduction, size and brightness of the

viewfinders. The Nikon D100 and Fujifilm S 3 Pro consistently scored best for color fidelity. Pentax and Konica-Minolta had the largest and brightest viewfinders.

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Refereed paper

Journal of Orthodontics JOR3338.3d The Charlesworth Group, Wakefield

Introduction

Intra- and extra-oral photography are widely used to document orthodontic patients at the start of treatment and to monitor treatment progress. The ideal character- istics for intra- and extra-oral photography for dentistry and orthodontics in particular, are reproducible magni- fication of the images, good depth of field and consistent, homogenous illumination. Ideally, all the above characteristics should be standardized within one

series of images, as well as consistent over long periods of time.1,2

‘Depth of field’ is defined as the zone of acceptable sharpness, and extends in front of and behind the point of focus. For good depth of field in intra-oral photo- graphy a small aperture (such as f522) should be used. Consistent exposure at such settings can best be achieved by automatic ‘through the lens’ (TTL) meter- ing.1 These settings should either be factory pre-set or should be easily programmable.

Although there are a large number of digital cameras advertised for use in dental imaging, only Single Lens Reflex (SLR) cameras consistently fulfill all the above

Address for correspondence: D. Bister, Department of Orthodontics, 22nd Floor, Guy’s and St Thomas’ Foundation Trust, Guy’s Hospital, London Bridge, London SE1 9RT, UK. Email: d.bister@doctors.org.uk

#2006 British Orthodontic Society

parameters. Additionally, SLR cameras allow for ‘best preview’ of the proposed image as the viewfinder shows the object, as it will appear in the eventual image.

In the pre-digital era the ‘Yashica Dental Eye’ was produced for intra- and extra-oral photography. This SLR camera had a 100 mm macro-lens, which was permanently fixed to the body with a built-in ring-flash. A macro-lens allows for distortion-free imaging at close range with high depth of field. The aperture settings were automatically adjusted when changing the focus from intra- to extra-oral photography, and was thereby very user friendly; no changes in camera settings are necessary between intra- and extra-oral photography. It was also reasonably priced. The ‘Dental Eye’, however, will not be made available in the digital format. In this article, this camera was used as reference, as it had all the above- mentioned ideal properties for dental photography.1

Digital SLR cameras have only recently become more affordable. SLR cameras are now subdivided into two groups: professional and ‘prosumer’. The professional group is more expensive, but usually has a range of advantageous features over the ‘prosumer’ group such as:

DOI 10.1179/146531205225021687