When lighting flat objects you want the light even over the entire surface. To do this you need two lights set at 45 degree angles so there are no hot spots or reflections. Lights courtesy of tabletop studios.
Click to explore hard and soft light.
This very complex
subject was shot in a lite tent. The soft diffuse light reached every part allowing it to be
captured without dark shadows and burned out highlights. http://www.
A medallion placed on a
light box and shot from above has a pure white background. A small lamp is used to side light the coin to bring out its relief. http://www.
Here a crystal glass was shot in a light cube against a black background to set it off.
A hole was cut in a
piece of black paper and placed on a light panel. The glass was then placed over the hole and looks like it's illuminated from within.
With a white background (top) the clock is underexposed but it's not with a gray background (bottom).
There are two important reasons to use artificial lighting in studio photography. First, increasing the level of light lets you use smaller apertures for greater depth of field, and faster shutter speeds to reduce blur from camera or subject movement. Second, you can better control the illumination of the subject, placing highlights and shadows to reduce or emphasize modeling.
Candidates for Studio Lighting
There are a number of subjects that lend themselves to being photographed under controlled lighting. Here are just some of them.
- Portraits can be either candid or more formal. Candid portraits are usually
captured during the flow of action. It's the more formal ones that give you
the time needed to arrange lighting.
- Small objects need to be illuminated properly to bring out details and colors. You can light a subject in several ways, depending on your objectives. For example, an object with low relief, such as a coin needs to be cross-lit to bring out details. Many objects photograph better in the diffuse lighting provided by a light tent. Flash can freeze action and increase depth of field.
Your options are varied, limited only by your willingness to experiment.
- Flat copy such as posters, stamps, prints, or pages from books require soft,
even light over their surface and the camera's image sensor must be exactly parallel to the subject to prevent "keystoning". Even then, many lenses will curve otherwise straight lines at the periphery of the image because they are not designed for copying and introduce what's called curvilinear or barrel distortion. There are other lens aberrations that make it difficult to keep the entire image in focus at the same time. One suggestion is to use a small aperture that increases depth of field and uses the center portion of the lens where aberrations are least likely to affect the image.
For good portraits or product shots, you need to improve on the camera's builtin flash. Direct on-camera flash doesn't give a picture the feeling of texture and depth that you can get from side-lighting or softer light. If you use an external flash, you can position the flash to illuminate the subject from an angle for a better lighting effect.
- Light tents bathe a subject in soft, even lighting and are particularly useful
for complex subjects such as bouquets, highly reflective subjects such as jewelry, and translucent subjects such as glassware. A subject placed in the light tent is surrounded by a translucent material which is lit from the outside. If the subject is small enough, you can use a plastic gallon milk bottle with the bottom cut out and the top enlarged for the camera lens. When positioned over the subject and illuminated by a pair of floodlights, the light inside the bottle is diffused by the translucent sides of the bottle. The result is a very even lighting of the subject.
- Studio lights are usually just reflectors mounted on adjustable stands. Keep
in mind that the color of the light you use to illuminate an object may affect the colors in the final image. For best results you need bulbs that are daylight balanced. The best of these are fluorescent because they don't give off any heat.
- Reflectors. When the light illuminating a small subject casts hard, dark
shadows, you can lighten them by arranging reflectors around the subject to bounce part of the light back onto the shadowed areas. You can use almost any relatively large, flat reflective object, including cardboard, cloth, or aluminum foil (crumpling the foil to wrinkle it, then opening it out again works best). Position the reflector so that it points toward the shadowed side of the subject.
As you adjust the angle of the reflector, you will be able to observe its effects on the shadows. Use a neutral-toned reflector so the color of the reflector doesn't add a color cast to the image.
- Light panels are an ideal source of light. When you place an object on the illuminated panel and shoot from above, the area surrounding the object is captured as pure white. If you cut a hole in a sheet of background paper and arrange it as a sweep, a glass placed on the hole appears to glow from within as light streams through the hole and through the glass. Finally, by tipping a panel on its side, it can be used as a background or used like any other light source.
- Flash. There is definitely a role for on-camera flash in studio photography. It
doesn't hurt to see what results you get from the built-in flash. A special kind of flash is the ring flash. These units fit around the lens and fire a circle of light on the subject. They are ideal for shadowless close-up photography such as that used in medical, dental, and nature photography. Because ring flash is so flat (shadowless), most units allow you to fire just one side or adjust the output of each side independently so the flash casts shadows that show surface modeling in the subject.
Some thought should be given to the background you use. It should be one that makes your subject jump out, and not overwhelm it. The safest background to use is a sheet of neutral gray poster board that can be formed into a sweep, a curved "L" shape that gives a nice smooth gradation of light behind the subject. It's safe, because it reduces potential exposure problems and most things show well against it. Other options include black or white backgrounds but they may cause some exposure problems unless you use exposure compensation. Finally, there are colored backgrounds, but these should be selected to support and not clash with the colors in the subject. The texture of the background is also a consideration. For example, black velvet has no reflections at all while black poster board might show them.
There are times when you don't want a background in a photo. This silhouettes the subject against a pure white background. You'll often see this technique used in catalog photos but it's also a great way to make it easy to select an object in a photo-editing program so you can cut it out and paste it into another image. To get this effect you need to overexpose the background. In some cases this is as easy as pointing lights at it. In the case of small objects, a light panel makes it very easy.
Focus and Exposure
The exposure procedure for close-up and tabletop photography isn't a lot different from normal photography but you have the opportunity to control lighting. The biggest difficulty may arise from automatic exposure. Many closeup photographs are of small objects that don't entirely fill the viewfinder frame. Automatic exposure systems can be fooled if the brightness of the small object is different from the brightness of the larger background. The meter averages all of the light reflecting from the scene and may select an exposure that makes the main subject too light or too dark. To correct this, you can use exposure compensation to lighten or darken the main subject.
Macro lenses are useful when you want to get close to small subjects so they fill the frame. Just keep in mind that in close-ups, depth of field gets very shallow.
Tips and Tricks
- When taking close-ups you can use spot metering to meter just a small part of the image so the background doesn't influence the exposure.
- When using flash for close-up images the flash may not fully illuminate the subject or be blocked by the lens. Be sure to take a test shot.
- To control exposure, use a neutral density filter, flash exposure compensation or flash exposure lock.
- If you don't get the colors you want, try different white balance settings. White balance can compensate for most lighting but when there is more than one light source, you may get color casts in your image. You'll have to experiment with this aspect, perhaps manually setting your own white balance if your camera has this feature. In other cases, you may find that you like the artificial colors or you may be able to adjust them in your photo-editing program.