II. Precautions
- Obtain Informed Consent to take medical images
- Take a picture of the Informed Consent and store with the Clinical Images
III. Preparations
- Cameras
- Smartphones (e.g. author uses the iphone)
- Readily available and offers high resolution images
- Digital SLR (e.g. author uses the Nikon D90)
- DSLR lens (e.g. macro lens) offers best image lighting and quality
- Spot focus and overall better functionality in a dedicated camera
- Higher resolution images offer more options for cropping the image
- Raw format images allow for maximal editing
- Smartphones (e.g. author uses the iphone)
- Software
- Photo-editing (e.g. author uses Photoshop)
IV. Technique: Image Quality
- Sharp camera focus
- Take multiple photographs
- Use 2 hand to minimize camera movement
- Camera may be difficult to autofocus at close range (macro)
- Take image at closest range for which autofocus works
- Crop image later
- Avoid distortion
- Take photograph at perpendicular angle
- Optimize lighting
- Avoid shadowing the subject
- Built in camera flashes typically offer poor lighting
- Consider external flash as an alternative (available with DSLR)
- Light the subject by a window or with lamps
- Skin lesions may be best seen with lighting shined at the object from a 30-40 degree angle from the camera
- Consider the high dynamic range (HDR) setting in cameras and imaging software
- Composites several images of the same object but with different lighting
V. Technique: Image composition
- Avoid patient identifiers in field of view
- Avoid unique Tattoos, clothing or jewelry
- Avoid patient ID wrist bands
- Remove distractions from photograph
- Optimize background to be uncluttered (remove wires, tubes and other distracting objects)
- Try to provide a smooth, unwrinkled, single color background (especially blue, black or white)
- Consider a towel or drape as background
- Provide clues to context and scale
- Photograph a wide shot and then a close-up
- Photograph one side compared with another
- Photograph with a ruler in the image or other standard object (e.g. coin)
VI. References
- Lin in Herbert (2014) EM:Rap 14(8): 7