The DAQ-E allows you to slide caps over the sensor to adjust the light measurement angle. Each cap has been characterized and calibrated, allowing for radiometric measurements with any cap installed. Use the white glass sunshine cap with its cosine corrector in bright light, such as outdoors in direct sunlight. Use the 90, 45, and 15 degree caps to narrow the capture angle. In our Chloros software, set the cap used so that the calibrated power measurements are correct.