Bare Bulb Light Footprint

[qupee]

What kind of light footprint - how high up the wall - will a 600w vs a 1kw bulb throw at a distance of 2 feet (distance from bulb to wall)?

All the info I can find on light foot prints is regarding horizontal reflectors or isn't very specific about vertical.

Can anyone who's run a 600w or 1kw vertically share their experience with how much wall area they cover 1.5 to 3 feet away from the bulb? Especially if anyone has run a 1kw with around 2 feet from bulb to wall (or screen) - can you share how you felt about that, if you had poor spread, hotspots, etc. or if that worked ok?

Assume temps and RH are in check, I'm just concerned about light spread and intensity.

 

[EyeC]

I hope someone with vert experience gets back to you. I think i saw another member post their vert bulb layout. Maybe in Tnelz thread? I'd like to know as well since i am considering adding some vert bulbs in to my game.

 

[EyeC]

@qupee This might help. More for big plants, but i am sure they could offer some insight.
https://www.thcfarmer.com/community/threads/distance-between-vert-lights-for-trees.58748/

 

[qupee]

It's surprising how elusive a clear answer on this is. I've been reading through tons of journals but it can be hard to apply when most journals are using different stuff. Like I'll find two 400's in a 6'x2.5' or stacked 600's in a 5x5' or two 1kw's in a 5x7, but it's like ya well if I had 5' instead of 4' a 1kw would be a no brainer, but I've got 4' across. I've even seen people reference that they've gotten a light meter and figured it out on their own but then don't say what spread the light is actually throwing for them.

I know 20w/sqft is a good reference amount for vertical canopy space but I don't know if that 1kw will be effectively lighting 2 or 3 feet up the wall, which of course makes trying to calculate my vertical canopy being lit and watts/sqft fairly useless.

 

[DrFever]

20 w per sq foot i think would be a disaster waiting to happen and double the work cause of the stretchy plant .. personally you need to ask your self why ??? do you have space limitations ???

 

[qupee]

20 w per sq foot i think would be a disaster waiting to happen and double the work cause of the stretchy plant .. personally you need to ask your self why ??? do you have space limitations ???

The calculation is different with 360° canopy and bare vertical bulb. In that situation 20w/sqft (of vertical canopy, in a circle around the bulb going up the wall or trellis) is the rule of thumb like 50w/sqft is for horiztonal bulbs in a reflector.

The floor space is 24sqft so it would be 41 & 2/3rds watts/sqft with 1000w and 50w/sqft with 2x600w if you're thinking horizontally.

 

[DrFever]

one must realize that being open and 360 degrees also loses power in 360 degrees also :) much faster then most think you ever wonder why there is no par tests whn hung vert and why multiple lighting ert grows do all the yielding rather then single donut verts