What lighting do I need for macrography?
This FAQ will detail some inexpensive methods to provide good lighting for small subjects. The techniques presented here are best applied to subjects that can be brought into an environment where lighting can be controlled, but can also be applied to natural subjects.
Four methods of adding light to a subject:
(3 involve flash)
The light from a flash is preferred because it can be controlled, and the color temperature of the light it produces is constant. Lighting a subject depends on the position of the flash units. With proper lighting, details dramatically stand out and colors are extremely precise.
1. Built-in Flash
Most digital cameras have a flash mounted right on the body. A built-in flash can be used in combination with other flash systems to provide even and non-directional lighting.
Most cameras allow the built-in flash to fire in macro mode; however, the close proximity of the flash to the subject may cause over saturation. In this case, the light should be attenuated (a couple of methods are explained further).
Lighting options are more restricted for cameras that do not allow macro-mode flash.. Incandescent lighting is required, and usually some way to diffuse the light (See Incandescent light below)..
A built-in flash tends to cause harsh shadows. This might be acceptable, but if the aim is to provide even lighting, then some way must be used to reflect some of the flash light around the subject (See ?Reflective box? below).
2. Slave flash
Inexpensive (and basic) slave flash units can be purchased readily. They are designed to fire at full power the moment it?s sensor detects a flash firing. It has a tripod mount, and is turned on simply by lifting the head. They can take up to 1 minute to recharge.
Slave flash units may not work with all digital cameras (Notably Olympus, Canon and Nikon).
The output from a slave flash may be hard to control (because it always fires at full power) without some light absorbing material (use neutral density filters as a backdrop), or by dispersing the light from the flash.
3. Remote Trigger Flash
Two elements are required: a remote flash trigger, and a stand alone flash unit. These expensive items are readily available in camera stores.
The remote trigger senses the flash from the camera and triggers the flash attached above. The system is simple and reliable, converting the light of the main flash to electrically trigger the flash to which the remote is attached.
I recommend the Vivitar 3000DT flash ($70 CDN, $45 US, 50? ). This flash system is one of the least expensive, but still offers a manual zoom head which can be adjusted for coverage between 28mm and 85mm, and 3 power settings. The trigger ($22 CDN, $14 US, 15.50 ? ) is off-the-shelf, and works with all flash units.
The remote trigger is mounted on a mini-tripod, with the flash attached to it. Mini tripods are practical, but not critical (Mini-tripods range $10 to $50+).
The combination of a quality flash unit and a remote trigger will work with the vast majority of cameras, including those that have a millisecond delay before firing the main flash burst.
Reflective box contruction:
While a plain colored surface can be used underneath and behind the ubject to be photographed, the light will remain strongly directed from the front. A cheap and effective method to reflect and diffuse light is to use a simple box lined with white poster board. The box is placed on white card stock which is sufficiently large so as to hide the background and make it invisible in the frame.
For cameras that have a user selectable white balance option, the white balance can be set for the combination of flash units and the white of the reflector box. This will usually yield more accurate colors.
If 2 extra slave units are used, then it becomes even easier to shoot without shadows. Furthermore, the extra flash units provide excellent lighting, even outdoors.
4. Incandescent light
For those cameras that automatically turn off the flash when the macro mode is engaged, the only workable alternative is incandescent lighting (halogen in particular).
Incandescents are difficult to use as they tend to create visual "hot spots"; however, when used in conjunction with a reflecting box, hot spots can be controlled to a great extent.
The lamp base should be whatever is practical or economical, but the socket should be able to take standard bulbs. Reflector bulbs are best as they focus light; at least two 50 Watt bulbs should be used.
The resulting images can be almost as good as those created using flash, but may require additional image processing using software to enhance the saturation and brighten the image.
Setting the white balance according to the temperature of the lights is critical to obtain faithful colors. Often photos captured under incandescent light appear warmer, even with the correct white balance, and less "staged" than using flash. This is due in large part to the lower light intensity, and different lighting color sources.