Standardized Photography for Skin Surface

Standard ized Photography f o r Sk i n S u r f a c e Jeannie Khavkin, MDa,*, David A.F. Ellis, MD, FRCSCa,b KEYWORDS  Dermatologic photography  Photographic documentation  Photographic standards  Digital photography  Facial resurfacing

variables, such as lighting, camera, exposure, focal length, white balance, and patient positioning, and their resultant effects on skin photography are discussed.

PHOTOGRAPHY EQUIPMENT Camera Digital single-lens-reflex (DSLR) cameras have replaced conventional 35-mm film cameras for most medical photography. The digital system is convenient to use because it allows for immediate viewing and evaluation of the images, many images can be taken without additional costs, and storage of images is quick and compact (Fig. 1). Camera features should include a high-quality liquid crystal display screen for image review and an accessory shoe to connect with an external flash device. A gridded viewing screen is beneficial for consistent subject positioning. In terms of resolution, cameras with 5 megapixels or higher are sufficient for the purposes of medical photography.1

Lens Lens selection is important for taking high-quality photographs and minimizing the amount of distortion. Lenses are classified by focal length. This measurement, defined in millimeters, is the distance between the optical center of the lens and the digital sensor when the lens is focused on

The authors have nothing to disclose. a Department of Otolaryngology-Head and Neck Surgery, University of Toronto, R. Fraser Elliott Building, 190 Elizabeth Street, Room 3S-438, Toronto, ON M5G 2N2, Canada b Art of Facial Surgery, 167 Sheppard Avenue West, Toronto, ON M2N 1M9, Canada * Corresponding author. 653 North Town Center Drive, Suite 308, Las Vegas, NV 89144. E-mail address: [email protected] Facial Plast Surg Clin N Am 19 (2011) 241–246 doi:10.1016/j.fsc.2011.04.001 1064-7406/11/$ – see front matter Ó 2011 Elsevier Inc. All rights reserved.

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High-quality photography is an essential part of any facial plastic surgery practice. Photographic documentation has a wide variety of clinical, research, and teaching applications and is also important for medicolegal purposes. Preoperative photographs assist in surgical planning and allow for effective communication of patients’ perceptions and wishes. Comparison of preoperative and postoperative photographs allows surgeons and patients to accurately evaluate the outcome of the procedure. Review of photographic outcomes provides a surgeon with an opportunity for self-assessment and modification of surgical technique. In addition, photographs play an important role in advertising and marketing. The prominent role of photography in facial cosmetic and reconstructive surgery places significant importance on using precisely defined standards during photodocumentation to achieve consistent and reproducible results. Standardized photography is especially important in facial resurfacing procedures where the changes are often subtle and variation in technique may demonstrate a clinical difference where none exists. In dermatologic photography, fine details, such as changes in skin texture, pigmentation, rhytids, and pore size, are evaluated to determine the efficacy of facial resurfacing procedures. The purpose of this review is to discuss how to obtain standardized, highquality images of skin surface. Photographic

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Khavkin & Ellis use the same focal length for preoperative and postoperative documentation to avoid inconsistencies. Fixed focal length lenses are also available and some authors recommend using a fixed focal length lens to ensure image consistency.2 Macro lenses are designed for nearfocusing and allow capture of facial details. For medical portraiture, a macro lens with a focal length of 90 to 105 mm is recommended to capture relevant details of facial anatomy.1,2 The range is extended to 120 mm for close-up dermatologic photography.3 Lenses with shorter focal lengths, such as 50 to 55 mm, create a noticeable midface distortion (Fig. 2).

Exposure Fig. 1. Example of DSLR camera.

infinity. This distance relates to the distance that the camera must be from the subject for the subject to be in focus. Most DSLR cameras come equipped with a zoom lens, which allows the photographer to change the focal length without changing lenses. If working with a zoom lens, it is imperative to

Exposure control plays a fundamental role in creating a high-quality image. To obtain consistent exposure, automatic exposure settings should be avoided. The camera mode should be set to manual and 3 camera variables that determine exposure must be set by the photographer: f-stop setting, shutter speed, and ISO. The amount of light that strikes the image sensor depends on aperture setting, also referred to as f-stop, and shutter speed. The aperture, much

Fig. 2. (A) Photograph taken using 105-mm lens. (B) Photograph taken using 55-mm lens creates noticeable distortion, such as increase in nasal size.

Standardized Photography for Skin Surface like the pupil of the eye, controls the amount of light that passes through the lens. Shutter speed, much like a blink, determines the length of time the light is allowed to hit the sensor. Proper aperture and shutter speed selection is critical for achieving accurate reproduction of the subject matter. F-stop number represents the ratio of the focal length of the lens to the diameter of the lens diaphragm opening. The larger the f-stop number, the smaller the diameter of the lens opening, the less light is allowed to strike the camera sensor. Each f-stop setting lets in half as much light as the next lower setting. The aperture of the camera also affects the depth of field, or the distance over which objects in the picture appear sharply focused. The larger the f-stop, the greater the depth of field. Typically, f/16 is desirable to ensure that all facial features are in focus. Patients with darker pigmentation may require f-stop to be lowered by half to 1 setting to brighten the image.4 To select an appropriate f-stop for a given studio setup, a series of test shots should be taken at varied f-stops. These images can then be examined to select the appropriate setting. Shutter speed affects the amount of light that enters the camera and controls the amount of movement seen in the photograph. For most photography in the office studio, shutter speed should be set to 1/60 seconds, a standard flash sync speed.2 ISO setting controls sensitivity of the camera sensor to light. The higher the ISO, the more sensitive the sensor is to light. In medical portraiture, an ISO of 200 is ideal to produce high-quality images.

BACKGROUND The purpose of the background is to eliminate distractions and to place full focus on patients. For medical photography, a medium to light blue background is ideal. Blue background is visually pleasing in black and white or in color photography, provides sufficient patient-background separation, complements all skin tones, does not overwhelm patients, and allows for a greater depth of field. Having the same blue background in all preprocedure and postprocedure photographs guarantees that changes in skin color are not reflective of the change in the lighting. A white background produces harsh shadows, whereas black background diminishes 3-dimensional quality of the image.4 The background should be without folds or creases and made of nonreflective material, such as matt paint, wallpaper, or cloth.

LIGHTING Lighting is a major variable that affects ultimate quality of the image. There are several lighting techniques that can be employed in medical photography. Using a single flash unit, such as a cameramounted flash, produces harsh and uneven lighting (Fig. 3). Using a ring flash tends to create an even, flat lighting, but may wash out color and skin tones.3 In rhinoplasty photography, a stronger light source is desirable to highlight details of the nasal anatomy. In contrast, for facial rejuvenation and resurfacing procedures and to capture facial redness and pigmentation, soft, even, diffuse light, devoid of shadows and sharp lines, is used. These lighting conditions are achieved by using multiple flash units and soft boxes or umbrellas, which act as diffusers to eliminate shadows and provide even lighting.5 Most investigators recommend using 2 light sources placed at 45 angles to patients.6–8 Additionally, a single backlight mounted centrally above, 1 to 3 ft from the background, or 2 backlights directed at 45 angles toward the background should be used to eliminate shadows in the background.5,6 Patients should be positioned at least 2 to 3 ft from the background.5 Light diffusers, such as soft boxes or umbrellas, should be placed in front of the main lights to provide even, soft lighting to the face (Fig. 4). An understanding of color temperature and white balance is important in achieving appropriate color balance of the images. Different light sources have different color temperatures, containing different amounts of red, green, and blue light (Fig. 5). White balance tells the camera which combination of red, green, and blue light should be perceived at pure white under given lighting conditions. Because lighting in the medical office studio is often mixed, white balance should be set to automatic to produce truest color results. If all the light in the medical studio comes from strobes, camera white balance may be set to flash.2 Electronic strobes are ideal light sources for medical photography studio.2 Other light sources include ambient light, such as overhead fluorescent lighting, and tungsten flood lights. These light sources may produce inaccuracies in skin tones. For example, images taken in fluorescent lighting may have a slight greenish tint to them, whereas tungsten lighting produces a yellow/orange hue. Strobe lights produce light at 5500 K, which is sufficient to overpower any uncontrollable ambient light; however, every attempt should still be made to minimize ambient light, both natural and artificial.

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Fig. 3. (A) Soft light with 2 flashes at 45 . (B) Strong, harsh single flash directed at patient creating uneven brightness and color.

PATIENT POSITIONING Flash 1

Backlight Background

45

Photographer

Subject

Backlight

Patient positioning is an important factor in achieving consistency and capturing pertinent anatomic details. All photographic distractors, such as hats, eyeglasses, jewelry, and scarves, should be removed. Patients should be advised to wear clothing in dark shades because light clothing may change the color tone by reflecting more light. Patients’ hair should be pulled away from the face to expose the forehead and both ears. Makeup is acceptable as long as it is not distracting or excessive. Importantly, because fine Type of Light

Color Temperature (K)

Candle Flame

1,500

Incandescent

3,000

Sunrise, Sunset

3,500

Midday Sun, Flash

5,500

Bright Sun, Clear Sky

6,000

Cloudy Sky, Shade

7,000

Blue Sky

9,000

Red Hue

Flash 2

Fig. 4. Suggested setup for a medical photography studio. The light sources are set up at 45 to the subject. Backlights are used to eliminate shadows in the background.

Blue Hue

Fig. 5. Color temperature of different sources of light.

Standardized Photography for Skin Surface rhytids and skin irregularities may be camouflaged by makeup, it is recommended that all makeup be removed before photography for resurfacing procedures.9 Facial expression can affect fine details of skin appearance. Smiling can accentuate periorbital wrinkles and nasolabial folds. Neutral facial expression is necessary to accurately access topography of the skin.3 Importantly, patients should be photographed with the same facial expression, whether smiling or neutral, before and after the procedure. The position of the head and neck and the direction of the gaze must be standardized to prevent distortion. Sommer and Mendelsohn10 demonstrated that small variation in patient

positioning can affect photographic interpretation. Specifically, neck extension or head protrusion can improve jaw line and reduce the appearance of submental soft tissue. Direction of gaze is also important to obtain accurate photographs. Having patients look up will improve the appearance of periorbital wrinkles.3 Identical patient positioning should be used during each photography session. The Frankfort plane has been used as a method of standardizing the horizontal plane in lateral, oblique, and frontal views.10 This imaginary line drawn from the top of the tragus to the infraorbital rim should be parallel to the floor. Because infraorbital rim is a bony landmark, it is not always easily found as a surface landmark and may need to be palpated

Fig. 6. Five standard views used in facial plastic surgery procedures. Frankfort horizontal line drawn from the top of the tragus to the infraorbital rim is used to guide proper head positioning. (A) Frontal view. (B) Right obilique view. (C) Right lateral view. (D) Left oblique view. (E) Left lateral view.

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Khavkin & Ellis and marked for proper positioning. Using a gridline display in the viewfinder may also aid in obtaining the proper Frankfort plane. For the frontal view, patients commonly tilt their head to either left or right. The midsagittal plane in the viewfinder should also be used to align the head position in frontal views. On lateral view, patients tend to lift their neck out of the Frankfort plane or rotate their head toward or away from the camera. Rotation toward the camera is detected when the other eye is visible. Slight rotation away from the camera is harder to detect. Maneuvers to ensure the proper lateral view involve asking patients to open their mouth and verifying the correct position by direct line of sight across the 2 oral commissures.11 Superimposing the eyelashes may also be used.12 Standardization of the oblique view can either be achieved by aligning medial canthus with the oral commissure or aligning the tip of the nose with the lateral cheek (Fig. 6). Standardization of photographic technique is critical for facial resurfacing procedures. Details of skin texture, rhytids, pore size, and pigmentation need to be captured and accurately assessed. Five views of patients are recommended with close-ups of the areas that are specifically addressed. The timing of photography is also important. If a series of treatments is planned, follow-up photographs need to be taken immediately before the next treatment to minimize edema and erythema.3 Photographs should be taken at the same distance to ensure uniform magnification. The axis of the camera lens should be maintained at patients’ eye level and in the same plane.2 Patients should be seated comfortably in a swivel chair. Markings on the floor may be placed to indicate the position of the patients’ stool and foot placement. It may be helpful to place markers at specific sites around the room for patients to fixate their gaze and head position for frontal, lateral, and oblique views.

SUMMARY Photography is an integral part of facial plastic surgery practice. Standardized photodocumentation allows for evaluation of surgical outcomes

and for effective communication between physicians and patients. In dermatologic procedures, fine details, such as pore size, skin texture, and rhytids, are evaluated by photographic analysis. Capturing these subtle changes requires consistent, standardized photographic technique.

REFERENCES 1. Swamy RS, Most SP. Pre- and postoperative portrait photography: standardizedphotos for various procedures. Facial Plast Surg Clin North Am 2010; 18:245–52. 2. Neff LL, Humphrey CD, Kriet JD. Setting up a medical portrait studio. Facial Plast Surg Clin North Am 2010;18:231–6. 3. Shah AR, Dayan SH, Hamilton GS. Pitfalls of photography for facial resurfacing and rejuvenation procedures. Facial Plast Surg 2005;21(2):154–61. 4. Kontis TC. Photography in facial plastic surgery. In: Papel ID, editor. Facial plastic and reconstructive surgery. 2nd edition. New York: Thieme; 2002. p. 116–24. 5. Galdino GM, DaSilva D, Gunter JP. Digital photography for rhinoplasty. Plast Reconstr Surg 2002; 109:1421–34. 6. DiBernardo BE, Adams RL, Krause J, et al. Photographic standards in plastic surgery. Plast Reconstr Surg 1998;102(2):559–68. 7. Archibald DJ, Carlson ML, Friedman O. Pitfalls of nonstandardized photography. Facial Plast Surg Clin North Am 2010;18:253–66. 8. Persichetti P, Simone P, Langella M, et al. Digital photography in plastic surgery: how to achieve reasonable standardization outside a photographic studio. Aesthetic Plast Surg 2007;31:194–200. 9. Henderson JL, Larrabee WF, Krieger BD. Photographic standards for facial plastic surgery. Arch Facial Plast Surg 2005;7:331–3. 10. Sommer DD, Mendelsohn M. Pitfalls of nonstandardized photography in facial plastic surgery patients. Plast Reconstr Surg 2004;114:10–4. 11. Davidson TM. Photography in facial plastic and reconstructive surgery. J Biol Photogr Assoc 1979; 47(2):59–67. 12. Thomas JR, Tardy ME Jr, Przekop H. Uniform photographic documentation in facial plastic surgery. Otolaryngol Clin North Am 1980;13(2):367–81.