You're looking for macro photography lighting tips. Here's what happened. I wanted to give you an article with 5 tips on using a strobe as the only light source. I hope you don't mind, but I came up with something so much better
But something else happened accidentally and I got a cool photo as a result. Has that ever happened to you before? You try to take use a certain photography technique and you achieve a surprisingly cool photo, almost by accident.
Check this out! I got a very interesting photograph resulting from overhead lighting. That's usually the worst thing to use-overhead lighting that is. Light from directly above is frequently undesirable to use with macro photography. This was a very simple macro photography setup. The bottom surface and the background were simple pieces of white foamcore/cardboard. The camera was mounted to a tripod set at the same height of the table.
The photo of the set-up above was taken with my point and shoot camera and it's pop-up flash, so you can't really see the effects of the spotlight hanging above the table on my subject or background.
I attached my Canon 20D equipped with an 85mm f-1.8 lens and three Opteka lens extension tubes to one of my tripods. You can see that my electronic flash was off to the side and aimed toward the center of the background only and not at all at my subject.
This photo of the set-up on the left was taken without using flash and it shows how the spotlight is brightly illuminating the background, just behind the glass filled with small, pink spheres.
The resulting photo below is pretty interesting.
The subject matter is actually a gelatinous material that is sold as crystals at our local store and is used to start roots from plant cuttings. When placed in water, the crystals swell dramatically and become pastel-colored spheres.
In the photo below, if you look carefully you can see the yellowish highlight on the top of the sphere. That is from the overhead spotlight that was left on during the exposure. I did not adjust the color settings on my camera at all.
The thin white highlights on both sides up high on my sphere are spectral reflections of the reflection from the strobe firing its light against the white background.
In portrait photography, a similar light that skims off the edges of your subject's face is a rim light. This is a good way to get separation from the background.
I was startled by the color of the resulting photograph. Compare the purplish photos above with the orange tinted photo below.
Here is where the big surprise came. Same subject matter below, but I forgot to turn the strobe back on in the photo below. The only change I made was to increase my exposure. I had to change the shutter speed to get a longer exposure with only the overhead spotlight providing any light.
What a dramatic example of color temperature differences in light sources.
Okay. I know I am a lighting geek, but for me that is a big part of the fun of digital photography. When I was in photography school I did not get any macro photography lighting tips, but we did cover two different ways to light glassware.
These translucent spheres have the same optical qualities as glassware. I found another web site that focuses on tabletop photography of glassware. It has a lot of tips on lighting glassware, using light boxes, dark and light backgrounds, and a few tricks that can be applied to your macro photography lighting set-ups. Here is the link to the site: tabletop photography-glassware.
With digital photography, the cost of experimenting and shooting many variations is only the time you invest. You don't have any film, processing, pr printing to do. That's what so cool about digital photography and it's something we often take for granted.
Having the LCD screen makes it even easier to review and adjust as you go.