What LEDs is everyone running and what do you think?

[evilc66]

It's true, and I'm probably partly responsible for that. They were easy to get, and cheap when compared to Luxeon back in the day when we were getting the DIY revolution started (my very first build actually used Rebels). There are some better options now as far as color rendering is concerned (Bridgelux arrays, not the Chinese "Bridgelux" LEDs, are great at this), but no one can hold a candle to Cree for output per watt.

[pjr]

Well good. Now I have someone to blame!

<jk> Your primer on LEDs from a few years ago was YEARS ahead of anyone.

[KrispyCritter]

So if "everyone" is using Cree then aren't we just getting the same thing over and over again from all these different manufacturers?

I mean, I realize that different combinations give us different parameters but over all isn't a blue in one companies fixture the same as a blue in another companies if they are both the Cree?

[evilc66]

Yes and no. There are differences in output, tint, and color temperature/wavelength depending on the bin ordered. Some bins are cheaper than others. Also, the rest of the support hardware (drivers, power supplies, optics, heatsink, etc...) can all vary greatly, and can affect the output and lifetime expectancy of the fixture. Sure, they may all be Cree based fixtures, but they aren't always created equal.

[KrispyCritter]

Yes and no. There are differences in output, tint, and color temperature/wavelength depending on the bin ordered. Some bins are cheaper than others. Also, the rest of the support hardware (drivers, power supplies, optics, heatsink, etc...) can all vary greatly, and can affect the output and lifetime expectancy of the fixture. Sure, they may all be Cree based fixtures, but they aren't always created equal.

I understand bin difference and that running diodes at different voltages also make a difference but it seems to me that all this is too much ado about very very minor difference....

Bin differences....big deal.....

heatsink, case, powersupply.....not a big deal to corals....longevity and such sure.....

[evilc66]

Ok, so the difference in LEDs is fairly minimal. After that, you are paying for features, configuration (LED spacing, colors etc...) stability, efficiency, and longevity.

Drive current (not voltage), lens quality (plays a much bigger role than you think), and LED temperature (related to heatsink quality) all have an effect on overall output, and as a result will have an effect on the corals.

Like I said, not all fixtures are created equal. Anyway, there are more fixtures out there using cheap Chinese LEDs than higher quality Cree LEDs.

[pjr]

Hey Evil, I just happened to run across a link on the RB site to a review by Jale Adams regarding the SB tubes and the LEDs they use.... a good augmentation to our discussion:

"These new tubes are using Cree-based, Edison and BridgeLux LEDs and the diodes are purchased without primary optics so SunBrite can apply their own, custom-designed primary optic with a native directivity of 60 degrees. Finally, all the diodes are hand-soldered to their PCB in SunBrite’s own factory where all the gen2 tubes are assembled in house. Perhaps the only downgrade from the original SunBrite LED tube is the lack of fine differences between color temperatures of the 5mm LEDs and the high powered one watters that are found in the Gen2. However, SunBrite makes up for it by offering a vast diversity of color combinations of lamps with white, blue, royal blue, red and UV LEDs. The even spread of a bank of these LED tubes rocking efficient primary optics makes for some respectably high PAR numbers..."

[Corvette Reefer]

Im building a led system i got a ratio of RB:CW:WW: 6:4:2 once i get it i can tell you if i like how it turns out.

[KrispyCritter]

Ok, so the difference in LEDs is fairly minimal. After that, you are paying for features, configuration (LED spacing, colors etc...) stability, efficiency, and longevity.

Drive current (not voltage), lens quality (plays a much bigger role than you think), and LED temperature (related to heatsink quality) all have an effect on overall output, and as a result will have an effect on the corals.

Like I said, not all fixtures are created equal. Anyway, there are more fixtures out there using cheap Chinese LEDs than higher quality Cree LEDs.

I agree that optics can play a huge role. They can make or break a fixture IMHO. You just cannot discount them. That is one reason that I am so amazed at all the non-optic fixtures out there...even with 3w LEDs.

Spacing is also a huge deal as well as alignment. That is where the banding comes in. If you run LEDs in stripes then you will get more noticeable banding. A little bit of randomness seems to work better but it is harder to wire....