INFLUENCE OF CAMERA POSITION AND LIGHTING IN RHINOPLASTY PHOTOGRAPHY, THE

Australian Journal of Oto-Laryngology, Jun 2004 by Heron, Nicola, Al-Ali, Saad, Bartley, Jim

Preoperative and postoperative rhinoplasty photography documents the initial nasal deformity and the results of surgery. This paper examines and discusses the influence of changing the common photographic variables of lighting and camera-subject position on the end photographic result of the front view of the nose in rhinoplasty. An experiment was carried out in which several variables in the photographic studio were altered individually to visualise their effects on the same individual. The resulting photographs were then analysed in comparison to the standard for differences in the appearance of the nose. Subtle changes in lighting and head camera positioning can have significant consequences in terms of the aesthetic nature of nasal symmetry. In studying colleagues' work it is important to look at the pupillary light reflexes to see what lighting system is being used and at the comparability of patient positioning before any relevant conclusions can be drawn about the quality of the surgery.

Introduction

Photography provides an accurate record for preoperative and postoperative assessment. It is a valuable communication and educational tool for the surgeon, patients and colleagues. However for valid comparisons to be made a number of photographic variables must be consistent, and carefully considered.

While considerable attention is given to rhinoplasty surgical techniques at meetings and workshops less attention is paid to what are effectively rhinoplasty measurement techniques. The nuances of photography are usually considered to be outside the realms of surgical knowledge and training. Although the importance of photographic consistency is repeatedly emphasized1, the results of photographic inconsistency are rarely documented or discussed. Subtle changes in the light source, light placement and direction as well as camera position relative to the subject can produce surprising changes in the perceived deviation, size or symmetry of the nose. At many meetings it is often apparent that these considerations have been overlooked when photographs are compared and contrasted. When it is pointed out the surgeons have inadvertently manipulated the image through photographic variability it is often dismissed as being irrelevant to the presentation. The purpose of this study is to investigate and discuss the effects of changing common photographic variables of lighting and camera subject position on the end photographic results.

Background

In medical photography three major forms of lighting are used: a ring flash, a single flash unit mounted on the camera or studio lighting. By looking at the reflection of the flash in the patient's eyes (or the shadows on the nose) one can usually determine the position and type of flash used when the photograph was taken2.

A ring flash consists of light that completely surrounds the circumference of the lens and provides shadowless lighting making it ideal for intranasal photographs but unsuitable for facial portraits as many of the contour details are lost by the flat lighting produced by these units2,3,4.

A flashlight mounted on the camera, angled toward the side, produces more shadows than the ring light system. Care must be taken to ensure that the light source is positioned in a constant relationship to the camera and subject in successive photographs.

There are two major studio light systems currently utilised by photographers: the key light system and the quarter light system. The key light system involves the use of one light (the key light) as the major light source, which produces the shadow pattern. The key light is moved around the camera in a horizontal plane until the nose and cheek shadows merge and then in a vertical plane until the shadow of the nose touches the comer of the mouth. A fill light, which is less intense with a softer more diffuse quality, is then positioned to light or fill in the area of the shadow on the face produced by the key light. Two backlights are used simultaneously to separate the subject from the background. The technique minimising shadowing, which from a surgical, visual and artistic perspective are necessary to define the nose.

Since the light sources are not of equal intensity and are placed asymmetrically the resultant light reflexes which are often used to define the nasal tip will also be asymmetrical; the final effect is an apparently deviated tip. The shadowing necessary to define the osseocartilaginous dorsum will be minimised.

The quarter light system utilises two lights of equal intensity, positioned at 45 degrees from the subject-camera axis and 2 feet above the subject's eye level3. The advantages of the quarter light system are:

1. Minimal light adjustment is required in this system providing easily reproducible photographs

2. Equal intensity lights on either side render oblique and lateral view comparable

3. Parallel light reflexes of equal intensity and shape are produced

The quarter light system used for medical photography tends to document irregularities and abnormalities whereas the key light system was originally designed for portrait photography to minimise deformity and complement the subject features.