Portraits
Portrait Photography for the Dentist
Cary Behle, DDS
Copyright 2001 Journal of the California Dental Association.
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The increase in popularity of esthetic dentistry and the dential profession’s enthusiasm for providing these services are leading to a new paradigm of dental practice. The design of a dental office must now relate to visual and esthetic values rather than just to treating disease or maintaining health. Photography has always been important in dentistry, mostly as documentation and more recently for patient education. Patients’ high esthetic expectations put great demands on professional providers. It is the duty of the dentist who provides esthetic services to become schooled in the goals of beauty for a person’s entire face, not just the teeth. Portrait photography heightens a dentist’s and patient’s value of the mouth as the center of beauty in the face. It helps educate the patient and dentist alike, is important for the education of other patients, creates value, markets the dentist’s services, enhances the image of the office, and helps in the evaluation and planning for cosmetic treatment. This paper describes the basics of portrait photography and a simple two-light and reflector arrangement that can be used in most offices.
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Although public interest in good-looking teeth and a great smile has consistently been high,1 the dental profession’s ability to satisfy this demand has been increasingly rapidly, thanks to a multitude of new materials and techniques. A recent USA Today survey2 found that when people were asked "If you could change your facial features, what would you change?" the largest percentage of responses had to do with the mouth (27 percent). The nose came in at a distant 13 percent. As physicians of the mouth, dentists are in the position to positively affect people’s self-esteem. Esthetic dentistry has finally become a mode of practice that is accepted by patients and dentists alike. However, this mode of practice requires a very different office layout, armamentaria, and way of communicating from the traditional dental practice. Since appearance and beauty are entirely visual, photography is perhaps the most important tool an esthetic dentist can use. Most dental photography of the past was for documentation and lecture-illustration purposes.3 More recently -- with easier to use cameras and film, video, or digital output -- patient-education use has expanded phenomenally; and this has resulted in a significant improvement in the willingness of patients to accept finer dentistry, a large percentage of which is discretionary. Now that esthetic restorative dentists have rightfully taken their place next to orthodontists, oral and maxillofacial surgeons, periodontists, endodontists, implant dentists, and plastic surgeons as "cosmetic experts," they must use the proper tools to diagnose, educate, and treat. Dental photography must now move into the realm of professional photographers and utilize "glamour" photography and portraiture as the main tool for either a "smile makeover" or a single central crown.
All that is needed is a camera, some type of lighting, and a space in the office to take the photos.
Cameras, Lenses, and Film
This discussion will be limited to 35 mm cameras, since that is by far the most popular format in use today. Professional photographers utilize mostly the bigger "medium format" cameras and film for portraiture, as they often enlarge prints to 16 x 20 inches or larger and need the detail provided by a larger film. There are many sizes of cameras and film that fit into this category, but most produce images that are five to 10 times larger than a 35 mm transparency. For the vast majority of dental uses, 35 mm transparencies, negatives, or digital backs will produce all the detail necessary for enlargements up to 8 x 10 or 11 x 14 inches.
The camera body itself is only used for film transportation and lens attachment, so it can be of the most simple, and therefore cheapest, type. It is not even necessary to have a light meter in it, although it is almost impossible to find a camera body without one. It is very helpful to have a motor drive, or winder, to advance the film; and these are almost universally included. The same camera and lens as the clinical camera can be used (Figures 1 and 2), but it is the author’s experience that a separate, simple setup is better for portraits. This way, a different film can be used. Ideally, the camera body should have a PC connection for external light sources (Figure 3). PC in this case does not refer to a personal computer, but rather to a universal connector in photography for external light sources. The flash on the intraoral camera needs to be turned off and a PC connection available to achieve the proper lighting. Unfortunately, most clinical cameras today have neither of these features. A simple, cheap, or even used camera body can be purchased for this use.
The best lenses to obtain proper perspective of peoples’ faces with 35 mm cameras are in the 80 to 120 mm focal length range. The normal "macro" lens used for clinical photography is 105 mm, so this can be used if the camera has a PC connection, or if the lens is removable. Zoom lenses are not necessary, as an 80 to 120 mm focal length requires a certain distance from the subject, usually 8 to 12 feet, and focusing is done by moving forward or backward. A used lens in this range can be purchased inexpensively. An 80 mm lens will require 6 to 8 feet and an 120 mm lens will require about 10 to 12 feet of room from the subject, depending on the amount of the head-and-shoulder area to be included in the image. An ideal focal length is probably 100 to 105 mm. Smaller focal lengths (35 to 80 mm) will result in distorted facial images by having a perspective too close to the subject (Photos 4 and 5). Longer focal lengths (greater than 120 mm) will result in much more space than necessary between photographer and subject and not change the perspective significantly.
Film options are numerous. The kind used depends on the intended purpose of the image. Most clinical photography is done with transparencies (slides, or positive images) because they are the truest and most vivid in color and the least expensive. With slides, there is only one original. With prints, the original (negative) must be printed to achieve a secondary image, with subsequent changes in color or loss of detail possible. The author’s experience is that most dental offices give the portraits to patients and use them in the office as displays on the wall or in albums. Print film is best for this use. There are specific professional films available for portrait work that are optimized for capturing the skin tones of humans. The photo lab that produces the print can also manipulate the final prints in many ways to achieve the appearance wanted. One example of a professional print film is Porta 160 from Eastman Kodak. The number 160 stands for the speed of the film (ISO 160). Many professionals shoot this film at ISO 100 to reduce contrast even further.
Digital cameras and camera backs are becoming more popular. The advantages are the lack of film and processing costs, the easy manipulation of the image via printer or computer software, the instant visualization of the image for possible improvement, and the printing capability via many different photo printers.
Portrait Lighting
Lighting is where the difference between clinical documentation and creative photography really shows. The photographer relies totally on artificial light and therefore starts with an empty studio, a totally blank slate. Almost all of the variations visible in magazine advertising photographs are due to lighting and the creativeness of the photographer. Posing and set design are also important, but in straight portraiture, the lighting is everything.
In modern still photography, lighting is accomplished with strobes (electronic flash tubes). Motion picture or video lighting requires that a light source be on all the time; this is the reason such a source is called a "hot light." This is not necessarily desirable in still photography. Strobes that are very close to the lens opening, as is the case with the ring lights used in clinical intraoral photography (Figures 1 and 2) or point-and-shoot cameras, result in "red eye" (Figures 6, 7 and 8). This is the reflection of the strobe light off the subject’s retina directly back into the camera. If the strobe is moved (Figures 9 and 10) at least 1 foot away from the camera lens, this reflection will generally not occur. If the lighting is directly in front of the subject, the resulting picture will have a flat, two-dimensional look (Figures 6, 7 and 11), since there are no shadows to define the depth of the subject or the third dimension. Therefore, moving the lighting off to the side will give more "depth" or "definition" to the subject (Figure 12). This is why professional wedding photographers hold a strobe in their other hand, or use extenders to raise the flash higher (Figures 10 and 11).
Likewise, moving the lighting above the subject (like normal sunlight) is much more natural than below (like the Frankenstein flashlight-under-the-chin look). The famous Dutch portrait painter Rembrandt used lighting above the subject in his painted portraits, so this has come to be called "Rembrandt lighting." The generally accepted position of this type of lighting is 45 degrees from straight ahead of the subject, and 45 degrees above the level with the subject. This type of lighting is also called "closed-loop" or "triangle" lighting, because of the highlight triangle formed on the cheek in the shadow side of the face, from the shadow of the nose (Figure 13). Generally the posing is such that the face is turned slightly toward the light source so the shadow side of the face is toward the camera.4 The shadow of the nose should not be touching the eye, or it will appear smaller than the other eye. This type of lighting also makes the subject appear thinner since the lighted side of the face is narrower than the shadow side. The author’s experience is that most patients like this light setup, which can also be called "thin" lighting.
The Main Light
The light used in the Rembrandt position is called the main light, and it can be regarded as a replacement for the sun. This light could be a strobe (flash) that would be attached to the camera by a cord and held there by hand (Figure 10) or any type of strobe that is mounted permanently in that position and then to the camera (Figure 14). "Studio" strobes come in a variety of sizes and strengths and are surprisingly inexpensive (Figures 15 and 16). Soft-boxes (Figure 17), umbrellas, and other diffusers of light soften this light source, which can be rather harsh or too revealing of facial discrepancies (Figures 6 and 7). A softening, haze, or diffusion filter on the camera lens also gives an attractive effect (Figure 12). Many subjects will immediately look at facial wrinkles in a photo rather than at the teeth. A soft-box on the strobe used with a soft-focus filter works as a "wrinkle remover."
The "classic portrait" is composed of three lights: a main light, a fill light positioned on the opposite side of the main light to fill in the shadows created by the main light, and an accent or hair light positioned behind and above the subject to give some "depth" to the image and separate the subject from the background (Figure 18).5
The Fill Light or Reflector
The author has found that a reflector placed close to the subject on the side opposite the main light, either below the subject (Figure 18) or anywhere from there to vertical, works perfectly as a fill light. Fill lights generally should be less intense than the main light in order to fill the shadows without eliminating them, and therefore leave the appearance of depth in the portrait. Setting the lights for different intensities utilizes the lighting ratio.6,7 A reflector will bounce back most, but not all, of the main light. The distance to the subject is also greater, and therefore the light is of less intensity by about the right amount, usually 1 f-stop. This eliminates the need to buy another strobe and set it correctly. Therefore the classic portrait setup consists of only two lights and a reflector (Figure 18).
The Hair Light
To make an image more vital, the hair light is necessary. This light is generally positioned behind the subject and above, but it can be positioned directly behind and hidden by the subject’s body. The subject should be at least 3 to 4 feet away from this light and the background. A longer distance is better. The average amount of space that is needed for proper portrait photography from the background to the camera is 10 to 15 feet or more. Proper photography cannot be done with less room than this. Therefore, in a dental office, photography is best set up at the end of a hallway or another suitable room. Dental operatories generally do not have this amount of available space. The hair light is a strobe similar to the main light and of the same strength; but, instead of a soft-box, it should have some sort of concentrating or focusing attachment such as a "snoot" (Figure 19) and should be permanently mounted on the wall in the proper position.
Backgrounds
There are two main types of lighting for portraits: high-key and low-key. High- key is where the subject’s face is darker than the background (Figure 20), and in low-key lighting, the face is lighter than the background (Figure 21) This can be done with a backdrop that is not lighted separately with a background light but only illuminated by the main light, or it can be controlled by lighting with different colored gel filters on a plain white background. The latter would require another light and make the setup a little more complicated. For someone who is just beginng to do portraits, it may be best to eliminate this light and use different-colored background papers or cloths. These can be purchased in photography stores in a multitude of colors, patterns, and sizes. High-key lighting definitely requires a background light, and it is difficult to set the exposure correctily. The author prefers low-key lighting in which the subject’s face is highlighted. Favorite colors are dark blue or black. Other primary colors are generally not flattering. Gray is neutral for all skin tones but tends not to be as dramatic (Figure 22).
The Subject and Posing
There are unlimited poses appropriate for portrait photography, and they are best learned from a photography book about portraiture;4,9 but generally the subject is seated or standing. A simple starting position is to have the subject turn the shoulders towards the main light, facing about halfway between directly at the light and directly at the camera, and leaning forward slightly (Figure 13). The best strobes have built-in modeling lights (Figure 15), which are incandescent bulbs that help the photographer determine how the strobe light will fall on the subject. The subject should turn his or her head toward the camera until the shadow of the nose falls just short of the eye on the shadow side. The ear on the lighted side should not show, or just barely. Tilting the head slightly toward the camera helps. The author generally prefers to light the right side of the subject; the main light will therefore be on the left of the camera. The reflector can be mounted on the opposite wall, mounted on a tripod stand, or held by an assistant. It is positioned at 90 degrees from the main light, on the shadow side of the subject, and at head level or lower. The photographer should be able to see the reflected light fill in the shadows from the modeling light as he or she moves the reflector around. It can be raised or lowered or positioned closer to the main light or further away depending on the effect seen. The hair light should then be directed at the back of the subject’s head with a snoot or some sort of narrowing of the light beam. A modeling light will assist in positioning. Different attachments can be procured at a photography supply store, along with strobes, reflectors, and other supplies.
The Proper Exposure
Once the lights are aligned and the subject positioned, it is necessary to set the camera to the proper exposure. This is accomplished with a flash/light meter that can be bought for about $200, or borrowed or rented8 (Figure 23). It might also be advisable to procure a professional photographer to help with determining the setup and exposure. Salespeople at a professional photo store should also be able to help. With a flash meter, the ISO number of the film used is entered, the f-stop (F 8 is average; it allows enough depth of field for the head, but allows background to be slightly blurred.) is entered, and a reading is taken of the intensity of the flash at the subject position. Ideally, the strobes are adjustable for output and can be modified accordingly. If not, the only way to vary the intensity of the light is to move the main light and hair light closer or farther from the subject to get the proper exposure.
Once the exposure is set and everything is in position, there is no reason for a flash meter. Test photos should be taken, developed, and evaluated, and modifications made if necessary. Everything is then done the same every time, and the portraits will be perfect.
Putting It All Together
Figures 24 though 29 show the effect of single and combination lights. The subject with only a main light in the Rembrandt position is shown in Figure 24. The hair light only is demonstrated in Figure 25. It is coming from above and behind, essentially the opposite position from the main light. Figure 26 shows the effect of both of these lights together. Adding a white reflector under the subject’s chin, as well as a soft-focus filter on the camera lens, results in the effect seen in Figure 27. Typical portrait photographs taken with this simple two-light setup are demonstrated in Figures 28 and 29. Figure 30 shows a portrait set up in a dental office.
Conclusion
Modern esthetic restorative dentistry requires treatment planning the entire face of a patient. This can involve the services of an orthodontist, oral and maxillofacial surgeon, periodontist, endodontist, implant dentist, and plastic surgeon. Full-face portrait photography is essential. Professional quality "glamour" photography, rather than clinical documentation, adds value for the patient, enhances the image of the doctor’s practice, and shows the artistic side of esthetic dentistry, not just the science.
References
1. Hambly CR, The Practice Builder, 11th ed. American Dental Publishing Co, Bradford, Pa, 1902, pp 204-9
2. A Survey of Facial Appearance Changes. USA Today, Dec 29, 2000.
3. Freehe CL, Clinical dental photography: equipment and techniques. In Clark J, ed, Clinical Dentistry, Vol 1. Harper & Row, New York, 1978, Chapter 1.
4. The Portrait: Professional Techniques and Practices in Portrait Photography, 1st ed. Eastman Kodak Co, Rochester, NY, 1993.
5. Kolomia P, Richards D, How to make a classic 3-light portrait. Popular Photography Sept 96:57.
6. Nicholas DC, Formal portrait lighting: some basic rules regarding your subject. Shutterbug Oct 95:62-8.
7. Craig J, How to determine a lighting ratio. Infoto Mar-Apr 96:6-7.
8. Schwartz T, Stoppee B, The Photographer’s Guide to Using Light. Amphoto, New York, 1986, pp 24-25
9. Shell B, Tips for better portraits for basic home studios. Shutterbug Oct 95:50-5.
Legends
Figure 1. A typical dental clinical camera with a ring-light strobe surrounding the end of the lens. This is as close as a flash can get to the lens. Perfect for intraoral work, it is terrible for portraits. It is sure to produce red eye.
Figure 2. A clinical "macro" camera with ring light used for close-up clinical photography.
Figure 3. A PC connection found on cameras that will allow attachment of a PC cord to fire a remote strobe and deactivate the on-camera flash.
Figure 4. Picture taken with on-camera flash and 35 mm lens. Notice the distorted facial features: a larger nose and changed facial proportions.
Figure 5. Same picture as Figure 4 with an 80 mm lens. Notice the normal proportions and perspective.
Figure 6. A "before" portrait taken with the camera in Figure 1. Notice the red eye, effect, which is the reflection of light off the subject’s retina due to flash being close to the lens.
Figure 7. An "after" picture taken with the camera in Figure 6. The red eye is still visible.
Figure 8. A standard 35 mm camera with a hot shoe-mounted flash on top of the camera. This is not enough separation of flash and lens and will still produce red eye.
Figure 9. Same camera as Figure 8 but with flash positioned straight up and an extender and white reflector. This will eliminate red eye and give a softer, more diffuse light.
Figure 10. Same camera and flash as in Figure 8, but with an extension cord attached to the camera hot shoe and the flash. This enables the photographer to hold the flash in any position desired. In this case, 45 degrees to the side and 45 degrees above the subject will create Rembrandt lighting.
Figure 11. Portrait-type lighting setup that can be used in close spaces. Macro photography brackets with dual flashes attached and small soft boxes over the flash output. This will soften the harsh light of flashes being too close to the subject, and eliminate "red-eye."
Figure 12. A two-light portrait of the same patient as Figures 6 and 7, utilizing a main light, hair light, reflector, and soft-focus filter.
Figure 13. Diagram of "short" lighting, that is, light illuminating the short side of the face, or the part that is less visible than the "broad" side facing the camera. Notice the lighted triangle on the subject’s left cheek. This is caused by the shadow of the nose and the direction of the lighting. Also notice the posing: turning of the shoulders towards the main light and a slight tilting of the head.
Figure 14. Permanently wall-mounted studio strobe with a cone-shaped reflector and white light diffuser over the end of the reflector.
Figure 15. Typical studio strobe with an incandescent modeling light inside a circular strobe bulb and adjustable dials for intensity of both strobe and modeling light. In this way, the light can be positioned correctly and the intensity adjusted to get the proper exposure without moving the light.
Figure 16. Inexpensive light-bulb-type strobe in a porcelain electrical socket. This operates in such a mode as to fire when another flash goes off, such as an on-camera flash. It’s output cannot be adjusted, and it must be physically moved closer or farther from the subject to get the right exposure.
Figure 17. A medium-size soft box attached to strobe in Figure 15. These can be bought in many different sizes and shapes, and can be fixed or collapsible. The purpose is to soften or diffuse the light on the subject to achieve more even, nondirectional light that is not harsh.
Figure 18. A two-light portrait setup with a reflector below the subject’s head, taking the place of a third, or "fill," light. The lights are a main light with a soft box and a hair light with a direction snoot. Notice the black background, posing stool, and position of subject’s shoulders facing the main light, with her head rotated to look at the camera.
Figure 19. A snoot attached to the light in Figure 15. This directs the light to a narrow area, which is helpful for the hair lighting.
Figure 20. High-key lighting. Notice that the subject’s face is darker than the background. This requires a background light and difficult exposure settings. Many photographers prefer this type of background for more full-body photos to highlight different clothing colors or body poses.
Figure 21. Low-key lighting. Notice that the subject’s face is lighter than the background. This does not require a background light and is more dramatic, isolating the subject and focusing attention on the face and, therefore, the smile.
Figure 22. Gray backgrounds are neutral for all skin types and hair colors but may not be as dramatic or flattering to many. In this case, no Rembrandt lighting was used, but rather two equal intensity main lights positioned on either side of the camera and diffused with white umbrella reflectors.
Figure 23. A typical incident light meter/flash meter used to determine exposure in many different types of lighting conditions, natural and artificial. For studio work, this will read the intensity of strobes and allow proper setting of cameras and lights.
Figure 24. Subject with only a main light, which is in the Rembrandt position
Figure 25. Subject with only a hair light behind and above.
Figure 26. Main and hair lights used together
Figure 27. Main light, hair light, white reflector under subject’s chin, and soft focus filter. Notice how the reflector fills in the shadows of the face compared to Figure 26.
Figure 28. Typical close up portrait taken with a two-light Rembrandt setup and reflector.
Figure 29. Similar lighting setup as Figure 28 but utilizing head, shoulders, and arms as well as a chair for a posing prop.
Figure 30. Typical portrait setup as described in the text. A main light with softbox is on the upper left. A hair light with focusing snoot is on upper right. A reflector is attached to swinging arm on right wall, positioned under the model’s left side. The model is sitting on a photo stool and leaning on a posing table, both of which can be purchased in a photography supply store for about $175 total. The black background is painted on the wall in a matte finish. The computer and printer on countertop are for input and output.
To request a printed copy of this article, please contact Cary Behle, DDS, 2840 Fifth Ave., Suite 300, San Diego, CA 92103 or drcary@theartofdentistrysd.com.
