Recomendamos este comentario a l editor aparecido en el J AM ACAD Dermatology de enero del 2022. Enviamos la tabla I y recomendamos su lectura completa
Savannah M. Alvarado, Paul Flessland, Jane M. Grant-Kels, Matthew McFarlane, and Hao Feng. Practical strategies for improving clinical photography of dark skin Notes & Comments J AM ACAD DERMATOL. 2022 VOLUME 86, NUMBER 1
Table I. Outline of specific recommendations for measures to improve clinical photography of dark skin in the typical dermatology practice
Setup 1. Prepare the skin. Gently clean the skin that will be photographed to remove any makeup and foreign debris. Remove all jewelry and excess hair from the area. Avoid removing secondary features, such as crust or scale, while cleaning.
2. Clean the lens. Use a soft cloth to wipe the camera lens prior to every use to ensure that the lens is clean.
3. Stabilize the camera. Use a tripod to stabilize the camera in order to clearly capture finite details. Details, especially subtle ones, may be somewhat obscured by melanin; therefore, high resolution is crucial. If unable to use a tripod, stabilize the camera by resting the bottom edge on a table or flat, steady surface.
4. Position the camera at an appropriate distance from the skin, about 3-4 feet away. Use zoom as necessary to obtain closer images. While photographing diffuse pathology, take both overview and focal photographs. Avoid zooming more than half of the capability of the camera because this may compromise the resolution of the image. This does not apply while using a macro lens. With these lenses, the camera can be held closer to the surface of the skin.
5. Use a plain, nonreflective backdrop. Use a plain wall or, when possible, a sheet as a backdrop. The background should provide moderate contrast to the tone of the skin; however, it should not be too light because this might lead to overexposed dark skin. The background should not be overly reflective because this may cast glare on the pathology. Do not compromise the quality of lighting for the sake of the backdrop. Light- to medium-toned royal-blue backdrops generally provide contrast to dark skin tones without casting abnormal hues onto the skin. Felt or other wrinkle-resistant fabric or matte photography background paper will provide the ideal backdrop texture, which should be uniform and nonreflective. Foam core sheets can be purchased at a craft store and used as an accessible and cost-effective background.
Lighting 1. Invest in an appropriate light source. Avoid the use of the built-in flash on a camera because these flashes reflect light off of the surface of the skin directly back into the lens, causing glare. An LED light source produces less glare while providing high-quality, uniform light. An LED ring light can be purchased at a low cost and can provide high-quality light and flexibility in positioning of the light for optimal clinical photography.
2. Angle the light source to avoid glare. For most images, position the light source and/or patient so that the brightest light is angled at 458 to the surface of the pathology. Positioning becomes very important when there is an inflexible light source.
3. Position the light source close to the skin. If you have access to a flexible lighting source (like a ring light), the light should be held as close to the surface of the skin as possible without inhibiting the frame of the image.
4. Adjust camera and lighting angles to highlight texture. Oblique lighting will better capture intricate details of the surface of the skin, especially when photographing raised lesions. This can be accomplished by positioning the light source at less than 458 to the surface of the pathology.
5. Capture several images of the same pathology. Use more than 1 camera and lighting angle to demonstrate variations in the appearance of pathology.
6. Seek even lighting across the surface of the skin. When relying on overhead room lighting, a large surface area is preferred. This will cast softer light onto the surface of the skin and allow for more accurate depiction of the texture and tones of the skin.
7. If there are multiple sources of light, try to use light sources with a congruent undertone. To obtain the most accurate depiction of color, use a light source with neutral, white tones rather than overly warm-toned light, which casts yellow hues, or overly cool-toned light, which casts blue hues. In general, natural light and camera flashes or ring lights cast subtle blue-white tones, whereas common overhead lights cast more substantial yellow-orange tones. When using a flash or ring light, it is best to use this as the main light source to the targeted area and decrease artificial ambient lighting.