Physical

• A black anodised circular aluminium enclosure
• Light-excluding rubber suction cap attaches OptiCAL to the screen

Sensor

• 44 mm² silicon sensor (UDT Instruments model 265)
• 13° fixed field-of-view
• CIE V_λ function f₁′ <3%, typically <2%
• Full-scale range is 2400 cd.m^-2 with a resolution of 0.1 cd.m^-2
• Traceable photopic and spectral calibration available

Interface

• Communication and power via RS-232 interface
• Control via vsgDesktop display calibration software or LightScan software