Scynce did a par reading test with an aogee but since it has a 120 degree optics for light it messes with the readings.
Yeah, you have to measure light a little bit different when it’s angled like that but you can still use the apogee. The apogee actually has an angle correction cosine programmed in, for corrections of 75 degree angles. IIRC, if you connect the mq-500 via USB, you can modify the angle of the cosine. To do this, you would take measurements of lighting by holding the sensor at an angle, and whichever angle gets the strongest reading, that’s what you would want to program you light to correct for. You might message apogee before purchasing to make sure I’m not thinking of another light that allows for changing the cosine, but I do know it’s set for 75 degree angle by default. If that’s not possible, they do have other sensors out there that record over a larger area, helping to negate the variance caused by the angle of the lighting.
this is actually what I was talking about when I said I thought some of their specs were a bit wonky, I think they probably got a bit confused in correcting for angles with the PAR levels. if it’s not calibrated correctly for the angles, it will show both levels that are too high and levels that are too low. What made me suspect they had troubles, was that their spec sheet claims efficacy of 1.87 umol/j at 450 watts of total power, which would equal out to a total of ~850 umol/s at full power. Which, funny enough, is what they actually list as the lights total output. Somehow their density readings though, we got some a hundred or so extra photons without adding any extra power, at a further distance and over a wider area. The lens they are using
could increase photon density by concentrating the light through the lens, but this would be at the loss of coverage area as it’s concentrating the light into a more narrow beam. The lenses they use are doing the opposite, they’re spreading the photons over a wider area, which would in turn lead to slightly lower photon density but over a wider area. i did look at their site, it seems their other lights use diodes that are rated at 2.15 umol/j, so it’s possible that spec sheet you sent is using older data and they actually went with diodes that have a higher efficacy rating, or they could have confused results between different models at well.
either way, I’m excited to see how it does for you. It definitely looks promising. Even if I’m correct, 850 umol is enough to get the job done well, and I’m sure as you experiment with it, you can get more out of the Watts you’re using as you play with which spectrums encourage better growth in which life stages of the plant.
