Focus-able lenses? Good idea?

Hi.

With all the talk about lenses, I thought I would reiterate my idea of making a focus-able COB lens -(like how the lens/mechanism on most LED flashlights works)...

Say you get a 5-COB DIY kit...You configure them in a square with one COB in each corner and the fifth one in the center...

In that scenario, it's likely that you will get a hot spot in the center...right? But, what if you could focus the center lens so that the distribution pattern was wider? And, in addition, the corner COBs could be focused to a tighter beam to avoid any overlapping with the center COB.

Wouldn't a focus-able lens facilitate being able to even-out the distribution of photons across the entire space and alleviate hot spots?

I don't have the ability to DIY very well, but I get high and get some ideas from time-to-time!

Anyway...if someone does it and makes millions....share with me, please!

I know I drew this rather poorly, but I was trying to show where the beams cross, there is the potential for hot spots and reflected light to occur (on left)....

....but IF the lenses could be focused, then the patterns could be tailored to suit the space better....no?

USUALLY when you have focus you must have multiple lenses. Which means loss of light of about 4% per lens if using high quality glass like German glass. So more lenses more loss. Also, the price on quality German glass is fucking high so cheap ass companies will be much much worse.

The reflector route would be the easiest and cheapest. You need a light reflection program and it would be pretty easy to come up with something. Just think 'hps adjust-a-wing reflector'.

Diffusers my friend. RZ for angelinas in particular.

The hotspot tends to be in the center anyway so adding a cob to the center will be difficult to mitigate. Better to just go with 6 cobs, or 4.

BM9AGS said:

USUALLY when you have focus you must have multiple lenses. Which means loss of light of about 4% per lens if using high quality glass like German glass. So more lenses more loss. Also, the price on quality German glass is fucking high so cheap ass companies will be much much worse.

Click to expand...

Just for the sake of discussion though...

What if you were to compensate for that known loss of light by driving the COBs a little harder? I think a lot of small-time growers (like myself) can absorb a little extra on the electricity bill each month since we aren't requiring a lot of electricity for our small-time grows. And, it seems that even-coverage is a common goal among COB light configurations.

@Rahz...Understood. But there is an equal amount of light that gets sent into the walls from either a 4 or a 6 COB setup and ends up being partially reflected back (depending on the reflectivity of the walls). Couldn't a focus-able lens route that otherwise reflected light away from the walls and onto the canopy better?

tstick said:

Just for the sake of discussion though...

What if you were to compensate for that known loss of light by driving the COBs a little harder? I think a lot of small-time growers (like myself) can absorb a little extra on the electricity bill each month since we aren't requiring a lot of electricity for our small-time grows. And, it seems that even-coverage is a common goal among COB light configurations.

@Rahz...Understood. But there is an equal amount of light that gets sent into the walls from either a 4 or a 6 COB setup and ends up being partially reflected back (depending on the reflectivity of the walls). Couldn't a focus-able lens route that otherwise reflected light away from the walls and onto the canopy better?

Click to expand...

Center of beam will still be hotter. I think the diffusion lenses and more cobs will always win. And I'm the guy that's running Stella HB lenses.

tstick said:

@Rahz...Understood. But there is an equal amount of light that gets sent into the walls from either a 4 or a 6 COB setup and ends up being partially reflected back (depending on the reflectivity of the walls). Couldn't a focus-able lens route that otherwise reflected light away from the walls and onto the canopy better?

Click to expand...

It might be interesting to play with a focus-able lens. OTOH, in a 5 cob setup running the center without optics, maybe with diffuser would be the best way to spread the light out.

It's also worth noting in defense of the 5 cob setup, as long as the center isn't hitting over 1500 then a hotspot isn't necessarly that bad a thing.

I'm not a fan of lenses in general but a focus-able lens would have the benefit of being able to hang the lamp at various distances and still get a proper beam.

@Growmau5 already real world proved that a diffuser is a wonderful remedy for hotspots. He used a diffuser on his Canopy 10 and ran par numbers with and without it. The distribution of light was quite abundant. He said that the diffuser evened it out beautifully.

I was wondering this very thing, but with the edition of each individual light being on a rotator, moving the light like spotlights. If you could keep all the lights constantly moving, couldnt you keep them much much closer?

I know kinda off topic, but what about dlp tv screen? There are 2 in it one with tint and the other is clear. It's a huge area 60"x36". I have a setup with it in it and it spreads the light and it magnifies the light. I get a 30,000L increase.
Just an idea. I also can't find any research on the effect if lenses affect growth. I don't think so cause we live in a huge lens.
The atmosphere causes lensing.