Would you use optics if ...

LoJack · 03/19/2012, 02:20 PM

Hey guys,

Would you use optics if you put your LED's inside of a canopy. My kit came with 80 degree optics ... I just don't see the point if the light has no where to go but down into the tank.

I could see if I was hanging them over the tank and going without the canopy, the optics would target the light into the tank, but are they necessary in a canopy approx 14" above the surface of the water?

reefnewbie83177 · 03/19/2012, 02:57 PM

Optics narrow the light to focus it into the tank. w/out optics the less have a 120 degree lens, which means that you are wasting a lot of light to the side of your canopy and it is not penetrating into the surface. However, if you put your lights only a few inches above the water surface it may not be needed. But I am a newb so don't quote me on this.

MarkGP · 03/19/2012, 03:53 PM

The canopy has nothing to do with using optics or not. Height of the tank and height of the LEDs above the water will determine the need for optics.

RCERNA280 · 03/19/2012, 10:49 PM

imo I don't like how the optics put those little beams shooting down your tank. I had the optics came with my kit but ended up not needing it. The light right now is about 10" above the water and it's not inside the canopy. I think you will benefit on using the optics if you were to hang the fixture high above your tank. Again this is just my opinion good luck

der_wille_zur_macht · 03/20/2012, 08:32 AM

Quote:

Originally Posted by reefnewbie83177

w/out optics the less have a 120 degree lens

The built-in optic varies significantly in width from model to model - some are as narrow as 90 degrees. It's also worth pointing out that LED manufacturers sometimes specify default width as a "viewing angle" with the intention of it being the full width of the beam, while optics are almost always named by their FWHM (full width at half maximum) angle.

Quote:

Originally Posted by MarkGP

The canopy has nothing to do with using optics or not. Height of the tank and height of the LEDs above the water will determine the need for optics.

This. Optics basically give you a way to trade off coverage for intensity, based on the height above the tank that you're placing the LEDs.

LoJack, how high up will the LEDs be? 80 degree optics might typically be used at heights around 10 - 14 inches or so. Anything lower than that and you probably don't need optics unless you have a non-typical build.

LoJack · 03/20/2012, 05:42 PM

I'll probably have my leds about 14 inches above the surface of the water.

der_wille_zur_macht · 03/20/2012, 05:57 PM

Should be fine for 80's then.

der_wille_zur_macht · 03/20/2012, 05:57 PM

Should be fine for 80's then.

zero26 · 03/20/2012, 06:30 PM

My lights are about 5 inches off the water, no optics.

nanojg · 03/21/2012, 05:57 AM

I would use at least 80 degree optics, although 60s would be better. Its a waste of light not to use them in anything over about 6" above the water in most situations.

hllywd · 03/21/2012, 08:58 AM

Mine are about 4" - 5" above the water depending on the wave action, and approximately 28.5" above the sand. I like my 80° optics. There is a lot of personal preference in the "correct" answer to you question. I'd suggest trying it both ways to see what works best for you.

Good Luck,
Tim

der_wille_zur_macht · 03/21/2012, 09:20 AM

Quote:

Originally Posted by hllywd

There is a lot of personal preference in the "correct" answer to you question.

Personal preference yes, but we are lucky in that in this case, it's easily quantifiable. Optics simply provide a mathematically predictable tradeoff between intensity and distribution.

LoJack · 03/21/2012, 02:44 PM

makes sense. Optics it is then.

I figured being only 14 inches above the water I'd get some pretty bad spotlighting with the optics.

I have 80 degree and have no issue with using them if its beneficial to my setup.

Thanks everyone

pandimus · 03/21/2012, 09:40 PM

where is a good place to buy optics at?

LoJack · 03/22/2012, 07:10 AM

rapidled.com was great to me. Awesome customer service and awesome shipping

My optics were included in the kit I bought ... but they sell all angles and in black and white.

taijiguy · 03/22/2012, 09:16 AM

I used optics on about half the lights in my rig. I used 10 degree to get a good piercing light to the bottom. The unfocused lights fill in nicely, so together they give a really good wash of light.
My understanding (what I've been told anyway, and I'm no light expert but I believe this to be true) is that the white light is mostly for our enjoyment anyway. The few corals I have in my tank (it's mainly a seahorse tank) seem to absolutely thrive under just the royal blues I have (9x10watt on a 72gal) so I built my lights to get the effect that I liked, which is to my taste. I think that's the main objective- build it the way you want it to look.

der_wille_zur_macht · 03/22/2012, 09:26 AM

Quote:

Originally Posted by taijiguy

My understanding (what I've been told anyway, and I'm no light expert but I believe this to be true) is that the white light is mostly for our enjoyment anyway.

That's an extremely difficult subject to distill to a single sentence like that. At a very basic level, the typical LEDs used (royal blue and white) both provide a significant amount of intensity within the PAR spectrum so IMHO it would be more correct to say that both types of LEDs can contribute usable light for corals.

However, without considering the various pigments in a specific coral, you really can't make anything other than a very general statement. Suffice to say, IMHO, both types of LEDs likely provide both photosyntheticly usable light AND visually appealing light in most circumstances.

katchupoy · 03/23/2012, 12:14 AM

I use optics mainly because,
1. Protection from water splash
2. Par difference compared to none.
3. More efficient, since your directing more light to the water and not to your eyes or on the sides.

I do not use optics if the led color I am using is at least more than 10 inches apart from the same color. Example 2 pcs of red led on each side of the tank. This will spread the light as much as possible across the tank without creating spotlighting or color banding.

hope this helps.

katchupoy · 03/23/2012, 12:25 AM

Quote:

Originally Posted by LoJack

makes sense. Optics it is then.

I figured being only 14 inches above the water I'd get some pretty bad spotlighting with the optics.

I have 80 degree and have no issue with using them if its beneficial to my setup.

Thanks everyone

I have 60 deg optics at 9 inches off water. No spotlighting. The more you go higher the narrower you will need. And like I mentioned above, as long as your colors are not too far apart with the same color then color spotting will not be an issue. 9inches off water with 65 deg optics has a more or less 15 inches diameter coverage at water surface. Now 15 inches dia is big enough for an overlap as long as the next same color is not too far.

also if I may add, the spotlighting is more obvious if viewed or seen from left to right than front to back.

03/19/2012, 02:20 PM	#1
LoJack Registered Member Join Date: Apr 2008 Location: Thompson, Manitoba, Canada Posts: 357	Would you use optics if ... Hey guys, Would you use optics if you put your LED's inside of a canopy. My kit came with 80 degree optics ... I just don't see the point if the light has no where to go but down into the tank. I could see if I was hanging them over the tank and going without the canopy, the optics would target the light into the tank, but are they necessary in a canopy approx 14" above the surface of the water?

03/19/2012, 10:49 PM	#4
RCERNA280 Rj Join Date: May 2010 Location: Pacifica, Ca Posts: 380	imo I don't like how the optics put those little beams shooting down your tank. I had the optics came with my kit but ended up not needing it. The light right now is about 10" above the water and it's not inside the canopy. I think you will benefit on using the optics if you were to hang the fixture high above your tank. Again this is just my opinion good luck __________________ RJ Current Tank Info: neverending project

03/20/2012, 05:57 PM	#7
der_wille_zur_macht Team RC Member Join Date: Sep 2003 Location: NY Posts: 16,618	Should be fine for 80's then. __________________ Inconveniencing marine life since 1992 "It is my personal belief that reef aquaria should be thriving communities of biodiversity, representative of their wild counterparts, and not merely collections of pretty specimens growing on tidy clean rock shelves covered in purple coralline algae." (Eric Borneman)

03/20/2012, 05:57 PM	#8
der_wille_zur_macht Team RC Member Join Date: Sep 2003 Location: NY Posts: 16,618	Should be fine for 80's then. __________________ Inconveniencing marine life since 1992 "It is my personal belief that reef aquaria should be thriving communities of biodiversity, representative of their wild counterparts, and not merely collections of pretty specimens growing on tidy clean rock shelves covered in purple coralline algae." (Eric Borneman)

03/20/2012, 06:30 PM	#9
zero26 MoneyPit Maestro Join Date: May 2009 Location: Washington MO Posts: 1,666	My lights are about 5 inches off the water, no optics. __________________ 90 AGA RR 50 Cree LED's with Apex control 50 gal sump Reef Octo 190 lbs live rock Vortech MP40w Tunze 6045 Blueline return 20L frag/Fuge tank with a DIY 12 LED light. Total water volume 140 Current Tank Info: LPS, SPS

03/19/2012, 02:57 PM	#2
reefnewbie83177 Registered Member Join Date: Nov 2011 Posts: 193	Optics narrow the light to focus it into the tank. w/out optics the less have a 120 degree lens, which means that you are wasting a lot of light to the side of your canopy and it is not penetrating into the surface. However, if you put your lights only a few inches above the water surface it may not be needed. But I am a newb so don't quote me on this.

03/19/2012, 03:53 PM	#3
MarkGP Why do I do this? Join Date: Dec 2005 Location: Bristol, RI Posts: 1,018	The canopy has nothing to do with using optics or not. Height of the tank and height of the LEDs above the water will determine the need for optics.

03/20/2012, 05:42 PM	#6
LoJack Registered Member Join Date: Apr 2008 Location: Thompson, Manitoba, Canada Posts: 357	I'll probably have my leds about 14 inches above the surface of the water.

03/21/2012, 05:57 AM	#10
nanojg Registered Member Join Date: Jan 2009 Location: Lubbock, Texas Posts: 2,227	I would use at least 80 degree optics, although 60s would be better. Its a waste of light not to use them in anything over about 6" above the water in most situations. __________________ 90 gallon: DIY LEDs, I-tech 100, MP20, MP40 24 JBJ: DIY LEDs

03/21/2012, 08:58 AM	#11
hllywd Premier World Traveler Join Date: Nov 2000 Location: Ohio Posts: 4,035	Mine are about 4" - 5" above the water depending on the wave action, and approximately 28.5" above the sand. I like my 80° optics. There is a lot of personal preference in the "correct" answer to you question. I'd suggest trying it both ways to see what works best for you. Good Luck, Tim __________________ "Would you rather fight 100 duck sized horses, or 1 horse sized duck?" Current Tank Info: 210 AGA RR, Apex, 96 Cree XR-Es - 50/50 CW & RB @ .6A on ELN 60-48Ds, DIY 6x18 Ca reactor, BM220 CS2 skimmer, Tunze 6100s, 42" ETSS/AE Tech refugium/sump

03/21/2012, 02:44 PM	#13
LoJack Registered Member Join Date: Apr 2008 Location: Thompson, Manitoba, Canada Posts: 357	makes sense. Optics it is then. I figured being only 14 inches above the water I'd get some pretty bad spotlighting with the optics. I have 80 degree and have no issue with using them if its beneficial to my setup. Thanks everyone

03/21/2012, 09:40 PM	#14
pandimus Registered Member Join Date: Jan 2009 Location: Palmdale Posts: 970	where is a good place to buy optics at? __________________ ~SFVR Member~ 125 Gal Long/50 Gal sump koralia 3 Tunze 6085/Reef Octopus NWB-150/ Reeflo blowhole 1450/Reef Angel controller Current Tank Info: 125 gal 72X18X22

03/22/2012, 07:10 AM	#15
LoJack Registered Member Join Date: Apr 2008 Location: Thompson, Manitoba, Canada Posts: 357	rapidled.com was great to me. Awesome customer service and awesome shipping My optics were included in the kit I bought ... but they sell all angles and in black and white.

03/22/2012, 09:16 AM	#16
taijiguy Registered Member Join Date: Apr 2011 Posts: 37	I used optics on about half the lights in my rig. I used 10 degree to get a good piercing light to the bottom. The unfocused lights fill in nicely, so together they give a really good wash of light. My understanding (what I've been told anyway, and I'm no light expert but I believe this to be true) is that the white light is mostly for our enjoyment anyway. The few corals I have in my tank (it's mainly a seahorse tank) seem to absolutely thrive under just the royal blues I have (9x10watt on a 72gal) so I built my lights to get the effect that I liked, which is to my taste. I think that's the main objective- build it the way you want it to look.

03/23/2012, 12:14 AM	#18
katchupoy Moved On Join Date: Feb 2003 Location: Kent, WA Posts: 1,550	I use optics mainly because, 1. Protection from water splash 2. Par difference compared to none. 3. More efficient, since your directing more light to the water and not to your eyes or on the sides. I do not use optics if the led color I am using is at least more than 10 inches apart from the same color. Example 2 pcs of red led on each side of the tank. This will spread the light as much as possible across the tank without creating spotlighting or color banding. hope this helps.