Fig. 4.

Irradiance measurements from an LPA before and after calibration. We set all the LEDs of an uncalibrated LPA to a constant Iris value and measured the irradiance of each well. We then calibrated the LPA and assigned all wells a constant Iris value such that the mean irradiance output by the calibrated LPA approximately matched that of the uncalibrated LPA (Fig. 4A) and measured the irradiance of each well. We did this at three light doses and each time observed significantly reduced irradiance variability (asterisks indicate p < 0.001 as calculated by Levene’s test for equality of variances). The dashed red lines depict the average irradiance across the whole LPA for each condition.