Cobs or QB which has better coverage

Which is better cobs or wb

  • Cobs

    Votes: 19 45.2%

  • Qb

    Votes: 23 54.8%
  • Total voters
    42
DankaDank

DankaDank

Well-Known Member
whytewidow said:
The only thing I'm worried about with qb. Is I run an uneven canopy alot. Bc I run several different strains at a time. As you can see in the pics I posted.
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You can get the same coverage with COB's, QB's and Strips they just need to be placed at different heights above the canopy. In this case if you need a bit of height COBs may be the best route.
 
Chip Green

Chip Green

Well-Known Member
If youre getting results like that with your modded light, the EB strips will not disappoint....
700ma 560mm 3500k over 2x2 squares is getting it done for me.....
As you mentioned, the multiple strains with uneven canopy is going to change the light saturation.
The flat canopy training made a marked improvement for my areas.
 
ganjamystic

ganjamystic

Well-Known Member
whytewidow said:
Got any pics of it in action
Click to expand...
there's plenty of budshots on my ig.. I don't really do full tent or garden shots but all the pics since mid october 2017 or so are 100% qb grown (prior to that I was using blurples too)...
whytewidow said:
The only thing I'm worried about with qb. Is I run an uneven canopy alot. Bc I run several different strains at a time. As you can see in the pics I posted.
Click to expand...
lol ya I'm always running several different strains... I honestly haven't even tried for an even canopy in forever...
 
3

3GT

Well-Known Member
DankaDank said:
You can get the same coverage with COB's, QB's and Strips they just need to be placed at different heights above the canopy. In this case if you need a bit of height COBs may be the best route.
Click to expand...
I don't see that being true, they all have very different footprints. Most desirable being strips. Cobs are almost a point source of light, same with the QB they have a hot spot in the middle.
 
DankaDank

DankaDank

Well-Known Member
3GT said:
I don't see that being true, they all have very different footprints. Most desirable being strips. Cobs are almost a point source of light, same with the QB they have a hot spot in the middle.
Click to expand...
If you position those point sources closer to the 4 corners you get a very even coverage with a bit more height.
With strips the coverage is great when they are very close to canopy but when they are lifted or they don't fit the area well, corners and edges suffer. At least this is what I have seen from testing.
 
3

3GT

Well-Known Member
DankaDank said:
If you position those point sources closer to the 4 corners you get a very even coverage with a bit more height.
With strips the coverage is great when they are very close to canopy but when they are lifted or they don't fit the area well, corners and edges suffer. At least this is what I have seen from testing.
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You get as much height/coverage as the power you're running really. Strips should be spaced closer together near the outside/edges to do just the same. I don't see how its not better having 100 cobs (strips) vs 1 cob? In any situation really.
 
ganjamystic

ganjamystic

Well-Known Member
DankaDank said:
You can get the same coverage with COB's, QB's and Strips they just need to be placed at different heights above the canopy. In this case if you need a bit of height COBs may be the best route.
Click to expand...
3GT said:
I don't see that being true, they all have very different footprints. Most desirable being strips. Cobs are almost a point source of light, same with the QB they have a hot spot in the middle.
Click to expand...
you're both right imo.. strips allow you to place the lights closer to the canopy while still achieving even coverage... but you can get even coverage with cobs and qbs too, they just have to be raised up a little to spread the light... apparently, running 1 bare cob per sq ft at about 12" results in nice even coverage (http://rollitup.org/t/new-style-samsung-lm561c-board.955201/page-4#post-13956483).. I find 1 qb per 2'x2' at a height of about 18"-20" results in even coverage (no par meter, just eyeballing it, but no noticeable shadows or hotspots)...
 
LEDandCoffee

LEDandCoffee

Well-Known Member
3GT said:
You get as much height/coverage as the power you're running really. Strips should be spaced closer together near the outside/edges to do just the same. I don't see how its not better having 100 cobs (strips) vs 1 cob? In any situation really.
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you're comparing 100 of something to 1 of something. how does that make any sense. No one is going to run one cob.
 
ganjamystic

ganjamystic

Well-Known Member
I think the main difference between DIY with cobs vs strips vs qbs is the complexity or simplicity of the build... i.e.

mounting 8 cobs to 8 heatsinks with thermal paste and cob holders, cutting and drilling aluminum and building a frame, and attaching the light engines to the frame
vs
mounting 22 strips to 22 c-channels, flat bars, or extruded aluminum heatsinks with thermal tape or thermal paste and screws, cutting and drilling aluminum and building a frame, and attaching the strip modules to the frame
vs
mounting 2 qbs to 1 heatsink with screws...

If I had more time and energy to build, I probably would have gone with strips, but the simplicity of the qbs was hard to beat.. so that's what ultimately made my decision
 
DankaDank

DankaDank

Well-Known Member
3GT said:
You get as much height/coverage as the power you're running really. Strips should be spaced closer together near the outside/edges to do just the same. I don't see how its not better having 100 cobs (strips) vs 1 cob? In any situation really.
Click to expand...
Strips should be positioned the way you mentioned but even then they would have to be closer to the tent wall to gain the same intensity a cob would have in corners without being as close. This results in more light hitting wall when light is raised.
Technically 1 Light source could be just as good as a thousand if its Spatial Radiation Pattern had an equal amount of light being emitted at all angles.
 
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