As a local, South African, brand of high performance premium lights it is not possible to sell a product that will result in large returns. For that reason it is almost impossible to compete against cheap overrated lights that are so easily available online. Until 2015 customers that bought online from foreign mail order shops most likely also got top end LED’s in there low cost lights. Although the rest of the light left much to be desired. But that has changed middle 2015 with the availability of low grade clone LED’s that look nearly identical to the leading LED manufacturers on the markets. As of 2016 it is highly unlikely to get any cheap “free international shipping” light with an original Cree, Osram or Philips LED’s. Regardless if the advert claims the moon and the stars. If you like to know more about how to identify the clone LED’s read this.
Lattice Bright XML2 and Cree XM-L2 on Noctigon stars
But the real question remains. How good or how bad are these lookalike LED’s really?
We set out to compare some of the clone LED’s to their original counterparts. You can find the orignal post here.
To simplify things we were interested to know how well these LED’s convert electrical power to light, this is called Luminous efficacy. Considering temperature is the Achilles heel for LED’s, we would also like to know how the Luminous efficacy effected over a range of temperatures. Notoriously cheap lights does not have good heat conductivity, and that is where you will find Lattice Bright LED’s.
First thing we did was to order two Lattice Bright XML2 LED’s. The T6 bin was the best the agent could provide. We also asked for natural white (5000-5500K). After they confirmed the sample order we also asked for the same from our Cree agent, Cree XM-L2 T6 5000k. A few weeks later we got the samples.
The setup is simple: Using a custom built Isometric sphere we compared the Lattice Bright XML2 output intensity and measured the temperature of the star and the power(Voltage and Current) that was applied. We did the same with the Cree XM-L2 T6 5000k.
Before we show you the results here are a few observations and assumptions:
- Our Isometric sphere is not calibrated.
- We used the Cree XM-L2 T6 Datasheets at 50deg as the reference point. Power and Lumens were calibrated accordingly
- Voltage was measured at the power supply not on the star of the LED. There were some drops in the wires but we compensated for that in the final results.
- Noctigon did not provide the LED’s. We just used their copper stars to give each LED the best chance to perform.
- The equipment is not laboratory equipment and these results should be considered for general information.
Test Setup. 1 home made Isometric sphere , Lux meter, Digital power supply, Multimeter(Temp), OLD CPU Heat sink
Temperature was measured on the star as close as possible to the LED.
The testing results:
The first thing that was very noticeable was the colour difference between the two lights. The Lattice Bright XML2 T6 was horrific blue. The fact that we asked for natural white and got royal bluish white LED’s should not be a big surprise considering the company we are dealing with.
Cree XM-L2 T6 5000k
Lattice Bright XML2 T6
The histogram shows clearly that the Lattice Bright LED’s are producing a huge amount of high spectrum blue light. In contrast the over lap on the Cree lights is excellent and would produce very good Colour rending index.
As the temperature increased, the difference in Luminous efficacy increased as well. In fact at 100 deg the Lattice Bright are more than two bins lower than the Cree Counterpart. Effectively exhibiting the some or less performance characteristic of a T4 Bin. It is interesting to note that the junction voltage of the Lattice Bright LED’s are not as heavily affected by the temperature as the Cree LED’s. This is probably the only area where the Lattice Bright has any advantage over the Cree.
Conclusions
It was no surprise that the Lattice Bright XML2 T6 did not compare well against the Original Cree XM-L2 T6. The advantage at 35deg is not that big but as the temperature increases the Cree increases its lead. Sadly the difference is not really that big even at 100deg with only a 13.8% lag in Luminous efficacy of LB. If the quality (Colour) of the light was no concern one could be excused to think the lower price point and the marginal loss in light can be accepted. But that would be ignoring the fact that Cree XM-L2 comes out in much higher bins. The U3 bin would have a Luminous efficacy of 112 lumen/watt at 100deg compared to the 82.3 Lumen/watt of the LB LED at 100deg. What this test does not address is reliability but if build quality is anything to go by then the Lattice Bright LED’s should be avoided.
Cheap lights are often plagued with bad thermal design and the use of low quality thermal paths if any results in LED running very hot. The effect is that this clones will find themself in a very big disadvantage to the higher quality and better performing Cree counterparts. This is just one more reason why brands add value to a product.
