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One issue that comes with MACRO photography is light loss due to macro accessories such as bellows or extension tubes. Some lenses may require an increase in exposure at macro setting in the 1:1 magnification ratio. It is best to use the camera in manual mode, make some tests and set your exposure manually.
As far as I am concerned Pre Flash is useless. To avoid "red eye" all one needs to do is use off camera flash for portrait and candid work. If this features is effecting your exposure control- shut it off, don't use it for critical work or get rid of it.
Of course, diffusion materials and tents absorb light as well- all the more reason for testing and establishing your own exposure indexes.
Depending on the subject you may want to use light that entails modeling (light and shadow) such as in the photography of biological specimens, small decorative objects and other items that need a sense of dimensionality- sometimes raw light is best for theses subjects.
If you are photographing highly polished or reflective subjects such as jewelry the tenting arrangement is probably best as will need a light field kind of reflection in the object. If you require shadow-less lighting such as in photographing electronic circuitry, surgical fields, intro-oral photography (for dentists) and other situations where you don't want one component of the image to cast shadows on the others, a RING LIGHT is required for this kind of work.
You don't need fancy gear to do basic macro work. Out of doors you can use natural light and simple reflectors made of white cards or aluminum foil. With digital equipment, you can adjust the white balance to accommodate simple tungsten or photo-flood lamps in inexpensive reflectors. Quartz type photographic lamps are a good choice because if there high output the will afford the kind of depth of field and higher rates of illumination that is necessary to provide adequate exposure, what with light loss due to extension issues and diffusion devices.
With film- you might want to use a higher speed emulsion- 400 is a good speed and nowadays there are no grain problems with this speed range. Color negative films such as Portra 400 and the equivalent Fugi product yield great color saturation, wide latitude and good color saturation and contrast.
Hope this helps! Ed
