I was wondering whether a flashlight with an SST-90 LED can't be replaced by a cluster of Cree XP-G's. I checked jtr1962's thread with lumen measurements, this is what I found:
- SST-90 driven at 35W (9A) puts out 2136 lumen
- 7x Cree XP-G (bin R5) puts out a whopping 3220 lumen if each LED is driven at 1.5A/5W (same total power consumption of 35W)
The Cree setup is more than 50% more efficient!
Another advantage is that more mass of the flashlight can be used for heat dissipation. For the SST-90 quite big and deep reflectors are used, for the Cree cluster there are cluster optics available, for example at http://www.cutter.com.au/products.php?cat=Cree+XPG . These have much lower profiles than the big reflectors, which results in more mass for heatsinking.
Concerning the price (I'll use retail prices here), an SST-90 costs about 32 USD, and 7 pieces of Cree XP-G R5 cost about 35 USD. The price of the optics cluster might be a bit more expensive than a single big reflector. All in all, the price of the cluster solution isn't that much more expensive than the SST-90 solution.
Here are a few charts comparing both light sources :
(source of the data : Jtr_1962's measurements at http://www.candlepowerforums.com/vb/showthread.php?t=89607 )
Most lights these days have high-medium-low, this is one of the possibilities for driving this setup :
- high at 35W : 3220 lumen vs. 2136 lumen +++ Cree is 1084 lumen or 50% brighter
- medium at 13.2W : 1634 lumen vs. 1063 lumen +++ Cree is 571 lumen or 54% brighter
- low at 5W : 746 lumen vs. 470 lumen +++ Cree is 276 lumen or 59% brighter
Now if we'd compare the brightness of the Luminus SST-90 to a 7x Cree setup, in high mode, the SST-90 performs similar to a Q5-bin setup. In low mode it performs comparable to Q2-bin. When were we impressed by Q2's? In 2006. Q5's? In 2007.
Seems to me like the SST-90 isn't that great at all. I wonder why a lot of manufacturers currently focus on the SST-90 flashlights, instead of building a much more efficient Cree cluster flashlight. Or am I overlooking something?
- SST-90 driven at 35W (9A) puts out 2136 lumen
- 7x Cree XP-G (bin R5) puts out a whopping 3220 lumen if each LED is driven at 1.5A/5W (same total power consumption of 35W)
The Cree setup is more than 50% more efficient!
Another advantage is that more mass of the flashlight can be used for heat dissipation. For the SST-90 quite big and deep reflectors are used, for the Cree cluster there are cluster optics available, for example at http://www.cutter.com.au/products.php?cat=Cree+XPG . These have much lower profiles than the big reflectors, which results in more mass for heatsinking.
Concerning the price (I'll use retail prices here), an SST-90 costs about 32 USD, and 7 pieces of Cree XP-G R5 cost about 35 USD. The price of the optics cluster might be a bit more expensive than a single big reflector. All in all, the price of the cluster solution isn't that much more expensive than the SST-90 solution.
Here are a few charts comparing both light sources :
(source of the data : Jtr_1962's measurements at http://www.candlepowerforums.com/vb/showthread.php?t=89607 )
Most lights these days have high-medium-low, this is one of the possibilities for driving this setup :
- high at 35W : 3220 lumen vs. 2136 lumen +++ Cree is 1084 lumen or 50% brighter
- medium at 13.2W : 1634 lumen vs. 1063 lumen +++ Cree is 571 lumen or 54% brighter
- low at 5W : 746 lumen vs. 470 lumen +++ Cree is 276 lumen or 59% brighter
Now if we'd compare the brightness of the Luminus SST-90 to a 7x Cree setup, in high mode, the SST-90 performs similar to a Q5-bin setup. In low mode it performs comparable to Q2-bin. When were we impressed by Q2's? In 2006. Q5's? In 2007.
Seems to me like the SST-90 isn't that great at all. I wonder why a lot of manufacturers currently focus on the SST-90 flashlights, instead of building a much more efficient Cree cluster flashlight. Or am I overlooking something?
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