“…We also used an LED (light-emitting diode) array device with 21 narrow-band LEDs with peak wavelengths of 365,375,390,403,422,435,451,471,495,514,525,540,560,577,590,595,620,630,657,673, and 686 nm to produce light of arbitrary spectral content (Belušič et al 2016). The quantum flux was controlled using 12-bit pulse width modulation at 1 kHz and a set of ND filters.…”