So... if you have to raise the damn fixture by 2' as a result of adding lenses... why the hell should I spend $300+ on lenses? I'm better off just leaving them at 140°, and keep the panel within 6"-12" above the canopy. I'd get a much better mixture of the wavelengths. Plus I'm planning a step-style perpetual cab.. the fixture is going to be the roof of the grow chamber, with the actual space being 36" x 18" x 36" high. Actual cab will be 48" x 24" x 72" high.. with insulated/soundproofed compartments for electrical, hydro, exhaust, carbon filter, etc...
Agree with you, i have used 60, 90, and 120 degree lenses. And by far 120s do the best because you can get it closer. but 90s would be good for tall grows with multiple lighting. the only bad thing about 120s is the spread is so wide it literally can go past 7x7ft, i wonder if using a high quality reflector off the side of the light fixture would be a better bet to concentrate at least some of light into a smaller 4x4 or something just like HID.
did some talking on it in the LED tech forum
My observation are, correct me if im wrong.
"the best height for 3w diodes is about 1ft-1.5" I've noticed closer than ft stunts bud development and they kinda do this phat short chunky stubby tops things but still put on weight just looks better to have bigger longer colas so i keep LEDs at optimal 18" away... but this is with one 288 chp 580w, Epistar LED with 3 watt diodes 2 volts a chip, 630ma.
For 90 degree diodes and 3w chips, 1.5-2ft is great or they will bleach.. kinda defeats the point of leds if you have to move it further away, but not sure if it evens out with higher lm amount for 90 degree lens? probably just balances out.
Intesity of the led or "Brightness" or "Penetration" is over looked at in the LED world, you can only supply a certain amount of Brightness (so to say, or photons) to a plant, this is why you can't put a light to close to a plant or it will bleach. I believe that it comes down to the amount of Lumens in a square ft. so having enough chips to provide the say 10,000 lumens in a square ft. at a certain amount a ft away is the trick, and to accomplish this we need diodes that are
1. High Quality Lm output &
2. Alot of them in a certain space to provide the Lm per square ft at a reasonable distance
As of now 3w watt LEDs Have the Brightness or Penetration , at pretty good levels for most type of growing. Yeh maybe 10w diodes would be nice.. but any brighter LED diodes we would have to space further away from the plants because of the intensity.
So more LEDs in the UNIT per Sq ft is what we want...so if we are trying to cover 4x4ft we need to make sure we keep the Lumens a Square ft high which is best accomplished by multiple LED units.
Thoughts anyone? this theory may be totally wrong....."
yeh meant they are running 2 watts a chip...not volts, 288 x 2watts a chip running at 576watts total. This light puts out avg 20,000 lumens from a 1.5ft away. and 38,000 at .5 to 1ft away. To Make a DIY LED to provide that many Lumens with CREE, OSRAMs etc. I Could Use half as many diodes to produce the same lumens/results. So thats 144 Diodes. 144 x (avg) $5 a chip thats = $720 (which is about the price of this epistar LED altogether) just for the chips, and for 2 heatsinks ($200) and 12 drivers($450) and supplies ($100). so total = around $1470 (with all the high quality parts etc. +-) to make a Light equivalent (output over +20,000lm) to the ones i have it would cost double the cost to put out the same lumens......So honestly the CHINAs with REAL epistar Leds are not that bad on price,. Yes they do burn twice as many watts as DIY is the only downfall, but for price its half as much to perform the same as DIY. Which is they only real bummer about DIY they prices are still high. So technically, it comes down to what you can afford. buy twice as many chinas with epistars get twice yield with twice as many watts, or cut the watts down and spend twice as much.
candela (millicandela) to lumen conversion wizard,11000=34.558 lumens
Epistars REDs are lower than most and i agree are lacking in lumens, but other wavelengths they make are a little better. I have charts with all the lm/w for Epistars.
Im with you on the DIY not against it, just wanted to let people know that, That epistars do work fine if you can't afford or have the know how to build your own. I've been using them for a couple years now, and have found out the proof that with epistars you have to use more watts than the HID you want to compare too, because there lack of efficiency. But they do perform great when you do.
Steradian
From Wikipedia, the free encyclopedia
The steradian (symbol: sr) is the SI unit of solid angle. It is used to describe two-dimensional angular spans in three-dimensional space, analogous to the way in which the radian describes angles in a plane. The name is derived from the Greek stereos for "solid" and the Latin radius for "ray, beam".
The steradian, like the radian, is dimensionless because 1 sr = m2·m−2 = 1. It is useful, however, to distinguish between dimensionless quantities of different nature, so in practice the symbol "sr" is used where appropriate, rather than the derived unit "1" or no unit at all. For example, radiant intensity can be measured in watts per steradian (W·sr−1). The steradian was formerly an SI supplementary unit, but this category was abolished from the SI in 1995 and the steradian is now considered an SI derived unit.
Farting about with export licences and lots of red tape, sorry 'bout that, things are never simpleMax......where are you at with your light??? Halfway through february -- thought you'd have it by now??
Hi there, I've been a bit absent from the thread as it has been going in a completely different direction as other information was being brought forward, but that is all good. Anyway to answer your question, the panel will be consuming 260watts and the price is going to be $590. It will do very well in veg but mainly designed for flowering. Like I said earlier on "I apologise for the delay" as the light design is finished but I am dealing with bureaucracy at the moment, however, as the grow journal will be starting soon I hope everyone on this forum will be watching ! As I said earlier, if it is a failure I will not sell the light but if it is a success I will welcome someone else to test it for an independent view point and just see what happens. I do NOT ever intend to rip ANYONE off ! I hope you have great success with your new light and if you do a grow journal let us all have the link to follow pleaseso what kinda of wattage and price range arfe we looking at now max? sorry if i missed sometyhing but idk where to start in this thread anymore. let me know cause i just bought my first led panel. quad ban. prob not going to be worth it in a couple months but w.e no tech really is.
First grow using pineapple chunk from Barneys farm, in Coco Coir. I have 2 Blackstar 500's power consumption 290watts each and I suppose I could do a side by side comparison if anyone want's that ?Maxpesh: Will you be growing via a method you are well versed in... ditto the strain? Kinda wish I had a good LED light to do an A/B for you, but damn, until recently, most haven't been worth the money. My suggestion is to find an LED grower who has spent ~ $600, so people can compare same price to performance.