Black Diamond Productions

PLM SYSTEM™ PRINCIPLES

Parabolic reflectors are often misunderstood by photographers. A common response to the PLM™ system is: "That looks like an umbrella – it can’t possibly perform the function of those gigantic deep parabolic reflectors offered by other manufacturers." In a conventional deep parabolic reflector (see fig. 1) only a portion of the available light is directed to the parabola and is directed as a focused beam toward the subject. The remainder (shown in red) escapes as unfocused spill light. In the PLM™ system (see fig. 2) the special 7" reflector directs all of the light onto the 16 segment parabolic surface in an exact 180° field. 100% of the light is focused by the parabola and none escapes as direct spill light. The result is higher output than a deep parabolic system, virtually no spill light, extremely even coverage and a lightweight, portable system that can be mounted on standard light stands and easily transported and set up.

By positioning the light unit at the exact focal point, the silver PLM™ light modifiers produce an extremely high-output narrow shaft of light with smooth coverage and feathered edges. This results in very large, virtually round light sources that produce intense yet soft lighting due to the vast f-stop increase in subject illumination over softboxes or conventional umbrellas. Moving the light unit into the parabola slightly defocuses the beam to produce a wider pattern at slightly lower output. The optional front diffuser converts the Silver PLM™ into an exceedingly efficient softbox with exceptional evenness across the face and moderately wide illumination patterns. PLM™ umbrellas with white satin fabric form virtually round bounce or shoot-through light sources with extremely even surface brightness and wide smooth lighting patterns. Optional black covers and front diffuser panels offer a wide array of lighting styles.

The PLM Umbrella Reflector should be used in all configurations with Paul C. Buff, Inc.™ lights for optimal performance

• Silver 16 Rib Parabolic Umbrella: Silver inside, black outside. Projects a soft but narrow beam of light with a pattern and high output similar to a 40° reflector. Two to three f-stops more output than a typical softbox. Available in 86”, 64” and 42” sizes.
• White 16 Rib Parabolic Umbrella: White satin diffusion/bounce fabric. Projects a wide, soft beam for soft studio lighting with uncontrolled spill. Available in 86”, 64” and 42” sizes.

Optional:

Black Outer Cover Fabric: Eliminates unwanted back spill-light when used with the white umbrella, further maximizing the output in bounce mode.  Also ideal for use with White Front Diffusion Fabric.  (note: this cover is not needed with the silver umbrella).

Link for more information: http://www.alienbees.com/plm.html

The best part of this release is the pricing – most large umbrellas are much more expensive – I will probably have to give one of these a try in the white with black outer cover setup.