An inherent problem of close-up photography is the narrow depth of field. As you move the camera closer to the subject or as the amount of available light decreases at higher magnifications, the lens aperture must be opened wider or he exposure time increased. Either step may result in a photograph that is out of focus. Electronic flash virtually eliminates this problem because it guarantees a reliable source of strong light. Also, a narrow lens opening may be used, thereby expanding the depth of field. At 5' use either a fairly weak flash with a guide number of about 8 and ASA 64, or a slightly stronger flash with a guide number of 20 and ASA 25. Some cameras now have a built-in flash.
Bellows and Tripod:
If you wish to photograph tiny objects, such as butterfly eggs and very young caterpillars, you may need to use a bellows attachment, which makes it easier to adjust the distance between the lens and the camera body. The bellows must be used with a tripod.