Soon after I bought my Olympus E-500 last December, I started searching for a light set-up for close-up photography, especially for outdoor use. For a while, I experimented with various combinations of LED lights attached on flexible arms to the camera body. But, they were either not bright enough or difficult to position properly. The built-in flash of the camera works fine up to a certain magnification after which the shadow of the lens is cast upon the subject. Also, flash light frequently creates harsh shadows.
Mini L Ring fits into the palm of your hand.
So when I saw this device in B&H Photo-Video's catalog about a week ago, I realized it was just what I had in mind. It arrived in yesterday's mail and I have been testing it since then.
Digi-Slave Mini L Ring Ultra contains 24 bright LED lights. It screws into the front of the lens. This model is for lenses with 52 mm threads. (There is another and more expensive model for cameras with larger threads.) A small dial is used to adjust the light intensity, although for most applications when the camera is hand-held, the highest intensity seems to be necessary to avoid using too slow a shutter speed.
Mini L Ring runs on either a 9V battery or a 9V DC wall transformer. The interesting thing was that the B&H catalog gave me the impression that a wall transformer was not supplied with this model and the instructions that came with the unit stated that a wall transformer was available for purchase from the company. Yet, there was one inside the box. The transformer is very useful if you, like me, do a lot of indoor macrophotography of specimens.
The light intensity of Mini L Ring is bright enough to be used as the sole light source in the absence of other lights. I especially tested for that, because I frequently go out at nite to photographs snails and slugs. The picture of the Anguispira fergusoni shell (diameter: 8.5 mm) below was taken with Mini L Ring in an otherwise dark room with a shutter speed of 1/80 s at f8 and at an ISO of 320. You will notice that there is an overexposed ring surrounding the shell in the middle. This is probably an unavoidable result of using a ring light relatively close to the subject. Once the picture is cropped, sharpened and its contrast increased slightly, however, it looks fine and evenly illuminated (second picture).
The biggest problem in using LED lights for photography is that they tend to cast a bluish hue. My camera's auto white balance setting cannot correct for that. I did a series of test shots while manually changing the color temperature setting of my E-500. I determined that the most correct color hues are obtained when the color temperature is set at about 9000 K. That was the color temperature setting I used for the shot of Anguispira fergusoni and made no subsequent color corrections. Outdoors, however, depending on the intensity of sunlight, a lower color temperature setting may be necessary (see the pictures below).
The part of the unit that sticks out in front of the lens is 27.8 mm thick, but it still leaves room to approach the subject close enough to establish focus at the highest (1:1) magnification of my Zuiko Digital 35 mm macro lens. I photographed the lens cap at 1:1 magnification (camera was handheld at 1/60 s, f6.3, ISO 400). The uneveness of the light intensity is more obvious (it gets brighter towards the edges), but I think the result would be acceptable for most purposes.
There are a few other drawbacks of Mini L Ring. At low magnifications the unit may slightly vignette the edges of the frame. And in certain configurations, especially outdoors, the battery compartment may get in the way and prevent one from bringing the lens close enough to the subject.
Those are, however, insignificant concerns. Once you figure out the correct white balance setting, this is a very useful light source for macrophotography.
Digi-Slave Mini L Ring Ultra is manufactured by the SR Inc.
I photographed the tiny Vertigo pygmaea dormant on a rock and the tiny aphid on a dead milkweed seed pod in my backyard this afternoon under an overcast sky using Mini L Ring as a fill-in light source. Both subjects were slightly underexposed, but that could have been avoided. The white balance was set at 9000 K for the aphid picture and at 8200 K for the Vertigo picture. No subsequent color corrections were made.