Cob is ran at 2100ma so it's about 50% efficient which means about that many watts are going to PAR production. 161 lumens per watt total of about 12241 lumens total. PPF of about 158.
I wanted to ask you about your opinion on primary lenses & why they're not used on COBs. Have you ever considered using them for protection?
But I will check that thread.
It's your eyes. The source is more diffuse when the lens is removed so less light makes it's way to your retina from what was the focal point of illumination.
How so, if you don't mind my asking?
Speculation, but I think because the lens disperses as well as "blunts" the light and depletes its efficacy.
The majority of light being emitted is on a straight path to the canopy and needs no lens or redirection. With a reflector the only light being affected by the optics is light that would fall outside the 90 degree cone. With a lens all the light is affected by the optics. So for instance, if a lens is 95% efficient then there is a 5% loss. If the reflector is 95% efficient but only 20% of the light is affected by the optics then there is a 1% loss.
So, what exactly is the advantages to primaries & why has it always been such a big deal to have them prior to cobs?
Without any optics a diodes radiation pattern will be around 120 degrees with a percentage even falling outside that cone. Running without optics can be done but the emitters/diodes will need to be very close to the canopy which also means the size of the lamp must be larger.
Actually, I think the phosphor coating is the primary if there is one on white cobs? I was thinking a thin price of glass or plastic would do the job cuz they don't bed them in silicone. But I'm having a hard time fully understanding. Read about this so long ago. I understood it as the silicone over the diodes in which captures the light & havests it for use is the primary. Anything that controls the beam angle is referred to as a secondary lens. When you're referring to optics, you'd be referring to a secondary lens I believe. This applies mostly non-cob lights as diodes have both in 1 watt & 3 watt versions. Silicone primaries & focusing secondaries. Follow what I'm saying?
So, No advantage to a thin flat lens over the cob? That would be considered the primary. Not to focus. That could be considered running bare cobs, instesd if it showed more generated light on the meters? Have you tried this? Sometimes the advantages of these silicone & secondary lenses outweigh the little bit of light loss through the glass.
