LEDs with reflectors

[Oshengems]

this has probably been answered before but I can’t find anything in this subject why don’t they make these leds with reflectors since leds are more of a single point of light compared to T5s, wasn’t that the game changer for metal halides when they came into the scene and some brands like ATI actually hold their status because of their reflectors I’m not an expert but it seems some are better than other but to me they all look the same mirror like plastic

 

[jent]

The reason reflectors make sense for MH is because the light is sent from the bulb in all directions. The reflector is designed to send the light in useless directions back down to where it can be used.

LED's don't work like that, they only send light in one direction. You then need a lens to make that light wider or more focused (depending on needs).

I suppose you could argue the lens should spread the light, then use a reflector to re-focus the light downward is possible. But I think it's likely a waste of energy / par. Better to focus on a lens that meets your needs to start with, and have more LED sources and blend that way.

 

[Oshengems]

Wouldn’t leds then provide more flexibility since lights are individually but just clustered together? pars we all know it’s not and issue with leds but spread is so relecting a few from the sides just to spread the light a bit more wouldn’t help even out hot spots so instead of beaming corals from a single cluster why not split it and reflect some of the light for a more even spread, just thought about it because with an radion xr30 I’m starting to see a bid of shade I see with just a bit of reflection I could probably have a wider spread

 

[Oshengems]

One example Radions xr30 use one cluster facing down the 2nd cluster split it bean them towards the sides on a large reflectors like the ones use for metal halides and this will help fill in some of the gaps where shade occurs give that area under the lights a better overall spread ?

 

[DSC reef]

I believe the mitras use a parabolic reflector. I don't have any experience with that light though.

 

[JDtimk]

I understand what you are getting at. Using a reflector to blend the pinpoint led light and then reflect the blended light into the tank. Would be interesting to see a prototype of that. I use diffusers on my radions and it helps to blend the light immensely. would highly recommend diffusers if you want more even spread of the light in your tank.

 

[Oshengems]

I believe the mitras use a parabolic reflector. I don't have any experience with that light though.

They seem to do but on the small Cluster not the overall fixture, I’m just curious why we don’t see more of that on leds, on a mh or t5 is a given it’s beneficial because it’s spreading lights 365 degrees around the bulb but with LEDs would at least side reflectors even out spread and hot spots and more importantly “shading”

 

[Oshengems]

I understand what you are getting at. Using a reflector to blend the pinpoint led light and then reflect the blended light into the tank. Would be interesting to see a prototype of that. I use diffusers on my radions and it helps to blend the light immensely. would highly recommend diffusers if you want more even spread of the light in your tank.

They definitely do blend the lights better but still doesn’t solve shading, in currently getting shade on a frag lol top is red it’s a bit slanted and the under side is completely white and that’s because I have my Radions horizontal but vertically light reaches the under belly a bit more I figured a reflector with a bigger wing span closer to the dimensions of my tank world drastically help this

 

[Oshengems]

I believe the mitras use a parabolic reflector. I don't have any experience with that light though.

I just read up on these Mitras and they are claiming this is what’s making their lights exceptionally different from other leds but I’m looking at these clusters and they look very similar to my old Maxspect razors which also claimed their new reflectors was the difference but I was still getting shade because the clusters are simple too small a cluster for a cube lets say 12”x12” yes the top middle will get a substantial amount of light but it’s still one point of light beaming down it’s not really reflected In all directions a bounce from a reflector def will reach in between just because of the angle the light will come from the top and a bit from the sides

 

[JDtimk]

Ah yeah. I gotcha. I run four xr 30s over my 120 plus i have a t5 on either side to deal with shading.

 

[hart24601]

I wondered the same thing years ago, something like how some LED headlights work where they shine into reflectors. However now I think we are going to see LEDs move to panel style fixtures instead which should work just as well. More LEDs but smaller and less power each and if using clusters they are numerous and small over the panel with a diffuser under them.

IMO for shading it all comes down to the footprint of the fixture. 8 bulb are a beast because the surface area of the light (reflectors and bulbs) is so large. Make a panel of LEDs the same footprint, not clusters but LEDs all the way to the edges of that footprint, and the shading performance will be similar. You see similar things with MH reflector size, a 12 x 12 reflector is going to give worse shading vs a 24 x 24 reflector since the light is being emitted from the surface area of the reflector. Now of course they are some variation, but I have found this to hold up pretty well. Kessils have such shading issues because the area of light emitted is a 2" circle vs an orphek with the LEDs spread out for example.

 

[Oshengems]

Perfect example Cars do it for the same reason better spread for a small clusters of leds so why this isn’t applied in this hobby ? Is there a reason for it

 

[hart24601]

Perfect example Cars do it for the same reason better spread for a small clusters of leds so why this isn’t applied in this hobby ? Is there a reason for it

I assume cost to prototype, bulky fixtures, and an overall lack of demand for something like this. Sure now dedicated sps folk might be interested now, but a strong market point of LEDs is the small form factor and elegant design of high end modules along with high PAR for the wattage which these might be less efficient. I just don't think they found it to be worth the effort although it's entirely possible it was tested and found to be rubbish, we just don't know. Perhaps the cost was found to be similar to just running multiple single modules.

However now it makes a lot more sense to do a panel light or stips with diffusers if needed. I think the time when that design could have been plausible is past now.

 

[oreo54]

this has probably been answered before but I can’t find anything in this subject why don’t they make these leds with reflectors since leds are more of a single point of light compared to T5s, wasn’t that the game changer for metal halides when they came into the scene and some brands like ATI actually hold their status because of their reflectors I’m not an expert but it seems some are better than other but to me they all look the same mirror like plastic

LED "native" beam angle is usually 120 degrees.
MH/t5's are 360 degrees..
That is a big part of the issue..


The mathematical precision in a reflectors design and QC determine "value"..

Oh and one needs to talk reflectors vs lenses..
There are reasons that reflectors and lenses work "better" at different angles..
I'd have to dig up some manuf replies but re: single emitters reflectors work "better" in the 60-90 degree range than the common TIR lenses.

The simple answer to your question is that above 45-50 degrees the efficiency of TIR optics drops off which is why we offer a range of 20mm reflectors to fill in the gap:
http://www.carclo-optics.com/optics-for-leds/reflector/diameter-20.0mm/

Beyond ~90 degrees bubble optics are more efficient than reflectors so our range switches to these:
http://www.carclo-optics.com/optics-for-leds/bubble/

I hope this helps.
Best regards
Bernie

Bernie Daniels • OEM Sales Manager

t: +44 (0)1753 575011
m: +44 (0)7976 268874
e: [email protected]

Also remember one is considering ind vs group LED.s
bluacro multi chip and reflector and diffuser..

 

[Lingwendil]

You see reflectors used in the lighting industry for LEDs all the time, generally for ceiling installations for can lighting applications, but for aquarium use we already have pretty wide dispersion that usually ends up getting focused back down to a tighter beam in order to increase PAR and overall intensity. Reflectors work well for wide angles but generally are better replaced by lenses when a tighter beam is required, and running individual reflectors still doesn't help with color mixing, unless very large and with the addition of some sort of diffusion material, otherwise you can still get color separation that is very noticeable. Reflectors also don't affect the direct light emitted from the LED, when a lens will focus all the light emitted. Reflectors also take up much more space, but can be more efficient, and appear to be smoother in distributing light, without having as sharp of a cutoff at the edges of the beam. Look at suppliers like Ledil, and read some app notes and datasheets. interesting stuff

FWIW, when you don't need laser-beam PAR concentration, reflectors work very well, and I actually like them better than lenses. They do however have limitations, in that they are pretty tall and wide, and most commercial solutions are geared towards COB types of arrays, so have limited real estate for LED arrays in the center focusing area. If using a dense LED array like kessil or BlueAcro types of layout they work extremely well.

 

[garbled]

On big COB LED's, they usually sell coliminators for them. It's basically a small reflector, and then the big lens mounts onto it.

In my build of my DIY COB's, I use 90' lenses, and then placed a 90' cone around the rim of the lens in addition. I found this doubled measured PAR underneath the light, vs without the cone. The cone was just white plastic.

You can see on the far light, it has the little cone. Downside is that it makes the edges of the lighting "harder".

 

[Smite]

Most go for LED for low power and the low profile sleek look. To get leds to shine straight side ways would take a large nipple like optic, the large optic would reduce par and the reflected light would be even less. The panel would be the best best to get wide coverage with minimal shading but you're stepping away from the sleek look and probably moving towards wide angle optics to blend well at that distance.

It wouldn't be very sleek but I'd like to see a curved/domed fixture so you'd get leds shining both down and angled forward to minimized shadowing. Like a giesemann spectra that's packed with pucks

 

[Oshengems]

I completely understand the lens angle and advantage of T5 & MH with reflectors light goin up is wasted but I remember my earlier days in the hobby and how reflectors made a huge difference specially in MH, so companies are choosing to stay away from reflectors and LEDs because of aesthetics reasonings I would not mind sacrificing a bit of look for a better evenly spread of light

On big COB LED's, they usually sell coliminators for them. It's basically a small reflector, and then the big lens mounts onto it.

In my build of my DIY COB's, I use 90' lenses, and then placed a 90' cone around the rim of the lens in addition. I found this doubled measured PAR underneath the light, vs without the cone. The cone was just white plastic.

You can see on the far light, it has the little cone. Downside is that it makes the edges of the lighting "harder".

See this is what I mean why don’t we see more of these, I own a Kessil which is in my sump and Radions on my display and their advertising coverage specially for the kessils is a joke I could only imagine how much a bigger reflector can inprove the spread of those lights, they have a very small reflector but it still a beam of light coming from one point to cover a tank

 

[Oshengems]

What makes ATI reflectors different from others like aquatic life ? I read someone comparing them and there seem to be a big difference.

I want to see Radions non sps and Radions sps version with reflectors I don’t mind bigger fixture at all And aim those extra warm whites they added on a reflector to actually really make a difference between the 2 fixtures, I’m in my way home to take a pic of a small frag I haven that’s gettin shadow and it’s literally the very top frag under the lights of course switch my light vertically can help but then I will need an extra one