fisheye photographs solar-radiation

Uses and limitations of hemispherical photography for estimating forest light environments

We compare hemispherical (fisheye) photography and direct measurement using dataloggers for quantifying light intensity (photon flux density) in a New Zealand forest remnant. The hemispherical method was generally accurate, and faster than using dataloggers, but deviated from measured light intensity at low light levels (<20% of full sunlight). For deeply shaded sites, diazo-paper chemical light meters may be more suitable.