Light Intensity; LED vs HID

ttystikk

ttystikk

Well-Known Member
nogod_ said:
You can only drop your light until the point of highest intensity damages your plants.

If you have one high power source over your canopy (HID or a highpower cob), you have really high intensity in the middle of your beam that is limiting how low you can drop your light and its giving the edges the shaft. (Somewhat mitigated by a quality reflector)

If you have 16 low(er) power points of light (say 35w a piece) then you are only limited by the highest intensity in the middle of one of those beams. You can drop your light a lot lower when the highest concentration of photons is coming from the center of a 35w emitter rather than a 1000w emitter.

Prefab units are not clustered together in a box because that is a good design for light distribution. Its just easier to build/ship a luminaire that way. The best designs have as many diodes as you can afford, driven as softly as you can afford, spread out as evenly over the canopy as you can logistically manage.
Click to expand...
Like this;
20160721_130722.jpg
 
OneHitDone

OneHitDone

Well-Known Member
wietefras said:
That is not true either

You get overlap from those 10 FL's and with that you will get roughly the same "penetration". It's not identical since the light is spread out better, but in the middle the HID will win and around the edges the 10 FL's will win. On average you will see the same "penetration".
Click to expand...
We are talking about at a distance from the source
 
Funkraum

Funkraum

Member
There was an old chart somewhere with regard to distance and light bulb etc. at the time of the chart the 400watt hps bulb won.

i like lights, any light is a god send to an indoor grower :)
 
Funkraum

Funkraum

Member
yep its a fair point you make, but its a good place to start, if you have a Dimmable ballast and your reflector are on pulleys i suppose you have the best of both worlds?

getting the light spread though is really important, and will make for a bumper crop of course dependent on healthy plants
 
Rahz

Rahz

Well-Known Member
If the 100w and 1000w had the same efficiency, then hanging 10 100w bulbs in a room, or 1 1000w in the room... the center point reading would be higher under the 1000w considering the way light is spread under bulb/hoods. However, the PPFD in the room would be almost the same. The only difference will depend on how much light each setup casts on the walls. If the walls were 100% reflective then the PPFD would be the same. This would also hold true regardless of how high the bulbs were hung.
 
Funkraum

Funkraum

Member
you could alter you reflector closer to the wall and and have the centres reflector more open pushing the light source deeper. i understand what you are saying the light bonces? is that what you are saying:eyesmoke:
 
captainmorgan

captainmorgan

Well-Known Member
Funkraum said:
yep its a fair point you make, but its a good place to start, if you have a Dimmable ballast and your reflector are on pulleys i suppose you have the best of both worlds?

getting the light spread though is really important, and will make for a bumper crop of course dependent on healthy plants
Click to expand...
Another problem I've noticed with these older charts is most seem to use very poor quality ( low efficiency ) LED fixtures to take readings off of which compounds the difference.
 
Funkraum

Funkraum

Member
i am out on quality fittings, there is quality, and then there is realistic prices, leds are expensive, that being said, i do have some led bars

i have a friend with gavita pro series lighting, and i still get better weight than him, and he run a sealed room with c02
 
Last edited:
ttystikk

ttystikk

Well-Known Member
captainmorgan said:
Another problem I've noticed with these older charts is most seem to use very poor quality ( low efficiency ) LED fixtures to take readings off of which compounds the difference.
Click to expand...
This is because LED has made such impressive advances in the past 5 years or so.
 
ttystikk

ttystikk

Well-Known Member
Funkraum said:
i am out on quality fittings, there is quality, and then there is realistic prices, leds are expensive, that being said, i do have some led bars

i have a friend with gavita pro series lighting, and i still get better weight than him, and he run a sealed room with c02
Click to expand...
COB LED isn't so expensive anymore.

Your buddy with gavita lighting is having the classic 'more isn't better' problem, lol
 
You must log in or register to reply here.
Top