Pro IV-A


Spectra Professional IV-A Light Meter System


The Spectra Professional IV-A model # 18002-A is an Advanced Digital Exposure Meter for motion picture video and digital photography lighting. This Internationally Acclaimed Industry Standard has received Technical Academy (OSCAR), Engineering Emmy and numerous international awards.

The Spectra Professional IV-A is compact and easy to use, it is the most comprehensive, and reliable light meter for motion picture, digital photography and video lighting. See Pro IV-A Detailed Description.

Spectra meters are the industry standard and choice of professionals for the past 75 years. 

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Features :

  • Widest Sensitivity Range Ever: Measures f/stop from f/0.35 to f/128, photographic illuminance from near total darkness -0.1 foot-candles to full 70,000 fc and 1 to 100,000 lx.

  • Contrast Ratio Measurement (Ratio Mode): The ratio of two readings from 1:1 to 999:1 can be instantly calculated and displayed thereby simplifying the set  up of any lighting situation, and in f/stop mode the difference in f/stop between a new reading and the last memorized measurement is displayed in precise 1/10-stop increments.

  • Averaging: Average of two reading and or continuous averaging in f/stop and foot-candle made possible.

  • True Digital Design: Multiple range liner circuit design controlled by a embedded microcomputer (other photographic meter are designed with the older logarithmic method - a single range circuit).

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  • MEASURING RANGE: One million to one (20 f/stop) direct reading Multiple Range Linear Circuit. Digital f/stop: f/0.35 to f/128 in 1/10-stop increments. Analog f/stop: f/0.7 to f/45 in 1/3-stop increments.

  • PHOTOGRAPHIC ILLUMINANCE: Footcandles 0.1 to 70,000 and lux 1 to 100,000.

  • CONTRAST RATIOS: Calculates ratio of key plus fill to fill light alone from 1:1 to 999:1.

  • F-STOP DIFFERENCE: Displayed in precise 1/10-stop increments up to Plus or Minus 12 f/stop.

  • AVERAGE: Average of two readings and or continuous averaging in f/stop and footcandle mode.

  • DISPLAY RANGE: ISO 3 to ISO 8,000 in 1/3-stop increments.

  • FRAMES PER SECOND: 2 to 360 (for motion picture cameras).

  • EXPOSURE TIME: 1/8000 sec to 30 minutes.

  • ADDITIONAL FUNCTIONS: Memory Recall switch is to recall stored reading in memory (M1), current reading in memory 2(M2) and/or the Ratio, Average and f/stop difference of the two readings.

  • LAMP: Electroluminescent lamp for backlit liquid crystal display.

  • POWER SOURCE: One 6 volt battery.

  • ESTIMATED BATTERY LIFE: Approximately one year with normal use.

  • WARRANTY: Two year limited warranty. Calibration is Traceable to National Institute of Standard Technology(NIST), Washington, DC.

  • All Spectra professional vi-a meters are supplied with :

Photoshere (for ambient light)
Photodisc (for key or directional light)
Leather carrying case
6-volt battery
Instructional manual and Warranty card


  • Available Colors: Spectra Professional VI-A is now available in living color






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The Spectra One degree Photospot is a unique optical accessory that converts your Spectra Professional IV-A into a high-sensitivity one degree Spotmeter for narrow-angle reflected-light measurements. Readings are displayed in reflected f/stop or in footlamberts in luminance mode. Professional IV-A-SP Detailed Description

Detailed Description




  Microscope Adapter

  Mini Probe

 ? Spectra IV-A Light Hood

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