The L-558 is the world's first light meter with compatible with OPTIONAL PocketWizard radio transmitter The L-558 includes Sekonic’s unique built-in retractable Lumisphere. The L-558 is also a true 1-degree spotmeter, with a parallax-free viewfinder The L-558 features an extra large, cool-green-illuminated full-information LCD panel that displays the complete range of readouts and modes as well as battery condition. Use the Lightmeter Sekonic L- 558 to read the light for perfect exposures. The L-558 includes a flash/ambient analyzing mode that simultaneously reads both flash and ambient light automatically, and can display combined flash-ambient readings. The L-558 includes a broad range of custom settings so pros and enthusiasts can tailor it to their individual working methods. The L-558R DUALMASTER incorporates an optional wireless triggering transmitter available. It has been designed to meet the challenges and demands of today’s film and digital photographers. The L-558R offers versatile functions, to accommodate the most critical and precise photographic shooting conditions without sacrificing ease of use and affordability. It offers superior performance with new, redefined standards for precise, multi-function exposure and analyzing controls. With a turn of a knob the L-558R changes from an incident meter to a 1 degree spot meter all combined into one rugged, compact, all-weather housing. It features a Digital 1 degree Spot viewfinder, which displays f-stops, shutter speeds, EV and more. In electronic flash measurement modes, the flash-analyzing feature simultaneously evaluates both flash and ambient light. Along with many features such as special light measurement modes, extended sensitivity range, custom calibration and CINE mode, it also offers custom settings. The L-558R’s flexible design accommodates your ever-changing shooting situations. That’s because it’s the world’s first multi-function meter with Digital Wireless Freedom built-in. With its built-in radio transmitter you now can simultaneously trigger your remote camera and or flash units and measure the flash output wirelessly, eliminating the use of unreliable PC-synch cords or shutter release cables.