Big reflector + LED

[noahhs]

I binge watched Coral Euphoria and drooled over Abe's SPS tank lit with metal halide. It got me wondering--can you get that natural a look with LED? Plenty of LED fixtures today have good spectral balance. I think it's a solved problem, more or less. The main problem today is that color emitters are spaced out. The ripples cast rainbow shadows. That looks unnatural. The exception is Kessil--their array is so dense it's basically a point source. The shadows are crisp, the spectrum is uniform. But a point source does not have spread, therefore you need two fixtures spaced out. But then ripples have a very noticeable dual shadow effect. Again, it looks unnatural.

The actual sky is not dark with two suns. It's bright with one sun. A good LED fixture would spread its light from a single point source to a wide area overhead. I want to mount a Kessil inside a reflector, to block its direct light, and reflect it in a broad spread out pattern. So I'm thinking about how to design a reflector. Or possibly use an existing one. Maybe from the world of photography.

Has anyone done this? I would love to see an example.

 

[oreo54]

I binge watched Coral Euphoria and drooled over Abe's SPS tank lit with metal halide. It got me wondering--can you get that natural a look with LED? Plenty of LED fixtures today have good spectral balance. I think it's a solved problem, more or less. The main problem today is that color emitters are spaced out. The ripples cast rainbow shadows. That looks unnatural. The exception is Kessil--their array is so dense it's basically a point source. The shadows are crisp, the spectrum is uniform. But a point source does not have spread, therefore you need two fixtures spaced out. But then ripples have a very noticeable dual shadow effect. Again, it looks unnatural.

The actual sky is not dark with two suns. It's bright with one sun. A good LED fixture would spread its light from a single point source to a wide area overhead. I want to mount a Kessil inside a reflector, to block its direct light, and reflect it in a broad spread out pattern. So I'm thinking about how to design a reflector. Or possibly use an existing one. Maybe from the world of photography.

Has anyone done this? I would love to see an example.

The Quanta Atlas is sort of a version of what you want.

A reminder that for larger tanks one may need 2 " mh suns"...


Height and focus blends colors and emulates the parallel rays of the sun.

There are other " sort ifs" like corn cob LEDs in brooder reflectors BUT the " color" is all wrong

Unlike my and t5 nobody's built a inherent " reef spectrum" type led this eliminating your color separation issues.

Yea there are like 14k and 10k white LEDs but the blue plus yellow/ green phosphor is a primative implementation

Well Kyocera did it "right" ..

Key Features of Kyocera Reef LEDs (CERAPHIC):
Full-Spectrum Mimicry: Combines violet LEDs and RGB phosphors to produce light similar to natural sunlight at various depths.
Customizable Spectrum: Allows tailoring the light to specific needs, from deep blue viewing to wavelengths optimal for coral photosynthesis.
Promotes Growth: Designed to provide ideal conditions for corals and aquatic plants, enhancing their vigor and health.
High Luminance Uniformity: Delivers consistent light without color separation, crucial for long-term growth.

Unfortunately LED design, in general, is in the " good enough" stage...

You want my sun. Get mh's.
Not to discourage trying though.

I could, say stick high wattage 6500k COB(s) surrounded in a field of say 14000k small emitters and get a pretty natural sun/ sky effect. Well more mh/ reflector like.
Bridgelux has the COBs. 6500k are hard to source though 5000k is easier.
May need to blend in some asst. blue leds in the " sky field". Blue/ white separations are not as shocking as say red white separations.

Just food for thought.

 

[djf91]

Everything you pointed out is the exact reason us MH users still use them.

Might just be better off going MH. You won’t regret it.

 

[X-37B]

I am going back to halides on my new build. Currently have 5 systems all led.
On my 150 I run 2 Photon 50's and 3 or4 uv/v bars.
I can give my system a very halide look if I turn up the white. Currently run them at 50%.

 

[Otago]

You could use a video LED light, there are units that go to 10k with very high CRI. I think they would actually be more accurate to the sun than a MH or aquarium LED.

 

[rtparty]

You could use a video LED light, there are units that go to 10k with very high CRI. I think they would actually be more accurate to the sun than a MH or aquarium LED.

Does the video LED have UV and IR? If not, it will never be more accurate to the sun than a halide

 

[Otago]

Does the video LED have UV and IR? If not, it will never be more accurate to the sun than a halide

You are right. I should've said " I think they would actually be more visually accurate to the sun than a MH or aquarium LED."

 

[oreo54]

You are right. I should've said " I think they would actually be more visually accurate to the sun than a MH or aquarium LED."

 

[noahhs]

The Quanta Atlas is sort of a version of what you want.

Interesting. The ring-shaped arrays and lenses seem to blend the emitters better than each emitter having its own lens. In his Reefstock interview, Luca the Quanta guy seems to treat color separation as a real issue. Of course the blend still isn't as perfect as Kessil since the array isn't as dense. But at least it has some spread.

I could, say stick high wattage 6500k COB(s) surrounded in a field of say 14000k small emitters and get a pretty natural sun/ sky effect.

I was picturing this concept, but again with Kessil fixtures. Mount a 35 degree white spotlight high up, and use big reflectors, or Fresnel lenses, for a couple blue fixtures.

Everything you pointed out is the exact reason us MH users still use them.

Might just be better off going MH. You won’t regret it.

Maybe. But I'm hoping to avoid the heat and bulb changes. Or really just having to care about old tech questions, like magnetic vs electronic ballasts. And the tuneability of LEDs is fun, especially Kessil's continuous twist-knobs for color gradent and intensity.

You could use a video LED light, there are units that go to 10k with very high CRI. I think they would actually be more accurate to the sun than a MH or aquarium LED.

Interesting. You know, it just occurred to me, what I'm looking for in a diffuse light fixture isn't the total solar radiation, but only the blue sky portion. Apparently that is called "Diffuse Sky Radiation". According to Wikipeda, its spectrum is:

 

[oreo54]

Interesting. The ring-shaped arrays and lenses seem to blend the emitters better than each emitter having its own lens. In his Reefstock interview, Luca the Quanta guy seems to treat color separation as a real issue. Of course the blend still isn't as perfect as Kessil since the array isn't as dense. But at least it has some spread.



I was picturing this concept, but again with Kessil fixtures. Mount a 35 degree white spotlight high up, and use big reflectors, or Fresnel lenses, for a couple blue fixtures.



Maybe. But I'm hoping to avoid the heat and bulb changes. Or really just having to care about old tech questions, like magnetic vs electronic ballasts. And the tuneability of LEDs is fun, especially Kessil's continuous twist-knobs for color gradent and intensity.



Interesting. You know, it just occurred to me, what I'm looking for in a diffuse light fixture isn't the total solar radiation, but only the blue sky portion. Apparently that is called "Diffuse Sky Radiation". According to Wikipeda, its spectrum is:

Unfortunately they don't show nm numbers. Spike is likely 410nm-ish.

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