Fig. 9.2 Compact fully automated digital camera. “Point and shoot” camera style

Practical Tips

Digital SLR

Be aware of the physical size of the unit. Larger cameras are more trouble to move around. Purchase a good tripod for steady shots. To get best use out of this style of camera it is best to have a dedicated photography space.

Compact Automatic

Great if you have to move between clinics, easily transportable. Purchase an extra battery. This is more important than a bigger memory card. Carry a charging unit with you just in case.

9.3 Resolution

Camera resolution is a commonly used selling point with digital cameras. As a general rule the higher the number of pixels the better the resolution and therefore the better the reproduction of the photograph. With more pixels though comes a higher cost of the camera. So how much is enough?

Most often 3 or 4 megapixels is sufficient for most purposes. Used at the highest resolution, each camera has sufficient space on its file storage for up to a hundred or so pictures. If one reduces the resolution on the camera often one can achieve storage of several hundred images. When photos are used only for the clinical record then such an approach is acceptable. However, there are pitfalls if you wish to publish the photos in a journal or if you wish to enlarge them significantly to display a particular feature or simply use a larger screen.

A digital photo of only, say 100 KB, might be very well reproduced on your laptop or office PC. However, if you wish to use that photo projected onto a large screen then the resolution is too poor to display the features properly. In my view, aim for a photo size of 500 KB to 1 MB, this will give the best flexibility. If you take a full face photo and need to display, for example, eyelashes, then you will need a photo size of perhaps 2 MB.

The common concern with many practitioners is the size of the storage files necessary to accommodate very high resolution photos in the numbers pertaining to most busy practices. This is a valid concern but the cost of digital storage is coming down quickly and by considerable margins. However, if your requirement is only your own clinical record, then a lower-resolution photo is acceptable (3–4 megapixel camera). But, if you have an interest in education, presentations, publishing, then invest in a high-resolution camera (anything above 6 is fine).

Practical Tips on Resolution

For clinical records a 3–4 megapixel camera is usually sufficient and will cost almost half the amount of a 8–10 megapixel camera.

Zoom capacity is very useful. Optical zoom is better than digital zoom. Look for a minimum of ×3 optical zoom. This is common to most cameras. If you can get ×5 optical zoom, then this is about all you should need.

Macro function is important. Some cameras have an extra close setting called “macro magnifying glass.”

When sending photos via email, your computer program might automatically reduce the resolution for faster transfer. You need to be aware of this because the quality at the other end might not be suitable for the intended purpose.

9.4 Lighting

In the author’s view, lighting is the key element to get right to display the subject well and honestly. Paying proper attention to this aspect will improve your photos greatly.

There are a number of lighting options available and the most common is the camera mounted flash. In the compact automatic camera, the flash is front mounted

Fig. 9.3 Front mounted flash with compact automatic camera showing shadowing on the background. This also obscures the features and outline of the subject

and therefore strikes the target in a unidirectional mode but also a divergent light stream. Although this produces a well lit surface, there is an increased difficulty with shadowing against the background screen (Fig. 9.3). Poor selection of exposure can easily “wash out” the features of the subject and this type of flash can make a face “flatter” because of the flooding unidirectional light.

The SLR type of camera also comes with an inbuilt camera mounted flash but most also have the capacity for mounting an extra flash. In this circumstance there is

an advantage to use a ring flash. As the name suggests, the shape of the flash bulb is a ring which produces a softer and more dispersed light source. Effectively, there are multiple points of light emission and each with a divergent character, and as there is considerable crossover of the light streams, a more diffuse end result is achieved. This gives a more even lighting of the subject and often will decrease the shadowing problems.

In the author’s view the best lighting is achieved by high levels of ambient light. In practice, almost always the ambient light comes from above the subject unless one has a dedicated photographic booth. In a booth situation one can place directional flash points from below as well. Most clinicians do not have the available space to dedicate to a properly set up photographic studio with properly placed and coordinated multiple flash points. Additionally, most clinicians will visit different venues and will not have consistent ambient conditions for photography.

The best ambient light is fluorescent with predominance in shorter wavelengths giving a brighter “clean” light. Halogen lights also have a blue predominance and give a good light. Incandescent lamps, commercially available in most buildings, have a predominance of slightly longer wavelengths and give a more yellow light. This is often referred to as a “warm light.” Camera flashes are generally a very bright “clean,” light with a predominance of shorter wavelengths.

Direct camera flash can “wash out” the finer details on the subject (Fig. 9.4). This is particularly in a facial

procedure where it is important to show this detail. Especially when the procedure involves improvement of skin texture and complexion these fine details of the skin are important to demonstrate in before and after photographs. Figure 9.5 shows a series of photographs taken at the same sitting, using the same camera and subject. Only the lighting elements have varied. In the first photo taken on a compact automatic, no flash was used. In this photo the color elements are softer because when using only ambient light there is a very diffuse light source. Fine details can be picked up quite easily. Because the light is largely from above, the shadowing in the acne scars is not washed out and provides the contrast necessary to display this feature. From the same position in using the automatic flash the colors are “warmer,” that is, more red and yellow on display. This is primarily because the greater amount of light flooding the subject alters the reflection of wavelengths differently and so the camera “sees” more intense color. The problem with this photo is that the flash is reflected quite strongly from the convexity of the malar eminence and almost completely washes out the detail here. The side of the cheek fares better in displaying the acne scars but also the fine shadowing seen in the earlier shot tends to obscure the detail of the acne scarring. Using the same camera and flash, but this time the camera is positioned at one meter and the camera zoom lens is used to create the same framing, the warmer colors are retained and there is more even distribution of light. Still, however, the malar eminence reflects more and does not achieve quite the same detail as the first “no flash” photo.

Why should the camera distance make any significant distance at all? After all light travels in straight lines and is so incredibly fast. All true, but the light from the flash is unidirectional but also divergent and so the intensity of the projected flash diminishes exponentially with distance traveled. So, one can make adjustments for the ambient conditions in varying locations by experimenting with both “flash” or “no flash” and with distance from the subject. There is a limit to this aspect of things though which you will find out in a less clinical setting particularly at night. When used with a flash, the camera also automatically selects a different aperture and shutter speed. If your subject is more than 3 m (10 ft) away then your subject will be almost fully blacked out. Try taking the same shot with the flash off; you might be surprised how well the photo turns out. Remember though the shutter speed is also slower and you need a steady hand.

a

b

c

Fig. 9.5 Do not use flash. The “low light” mechanism of the camera will compensate to produce a good quality image with good exposure. (a) Compact automatic, no flash, set on macro, camera distance 300 mm. (b) Compact automatic, with flash, set on macro, camera distance 300 mm. note some loss of detail and washed out appearance of the malar eminence. (c) Compact automatic, with flash, camera distance 1,000 mm and using camera zoom to get a similar framing. Note that the malar eminence is still a little washed out but not as much as the earlier photo. From a purely photographic perspective the subject has more color definition and the end result is a “warmer” image