LED test / review
EN
Nichia Optisolis 3000 / 5000 K
NF2W757G-F1 / NF2L757G-F1
Some months ago Nichia announced a press release fort he new Optisolis LED series, emitters with ultra-high CRI „that demonstrates the closest match to that of the standard illuminant“, Nichia says.
This is achieved by a new developed LED chip and a mix of unique red and green phosphor.
I got some samples from BLF member clemence (‚Virence‘) for testing. Thanks a lot for these! :)
Technical data
Tj 25 °C unless noted otherwise
Order code: NF2W757G-F1 (white)
Type: lateral, multi die
Binning: ---
Rated voltage: typ. 2.9 V
Forward current (Tj 150 °C): 100 mA
Pulse forward current: 130 mA
Viewing angle: 120 °
CCT: 5000 K typ.
Thermal resistance: typ. 24 °C/W, max 30 °C/W
Junction temp.: max 120 °C
Order code: NF2L757G-F1 (warm white)
Type: lateral, multi die
Binning: ---
Rated voltage: typ. 2.76 V
Forward current (Tj 150 °C): 150 mA
Pulse forward current: 200 mA
Viewing angle: 120 °
CCT: 3000 K typ.
Thermal resistance: typ. 21 °C/W, max 27 °C/W
Junction temp.: max 120 °C
Interesting are the different electric characteristics of both Optisolis types. Overall the warm white version is more powerful and has also less thermal resistance. With 120 °C the maximum Tj is much lower than other LEDs (135 or 150 °C) which could limits the maximum overcurrent in a negative manner.
Appearance and die
Unless classic high power LED the Optisolis is different in design and footprint. Like most other low- and mid-power LEDs in this class the case is made of white epoxy resin and the two non-symmetric dies are embedded in a silicone layer. Everyone of them is connected with two very small bonding wires which could limits the maximum overcurrent possible.
Comparison with classic 3535 emitter (XP-G2, right)
A single Optisolis LED fits easily on a XP- or XM-board, with the bigger contact on thermal pad. But there is also more possible, like shown here with four Optisolis emitters on a single XM-board:
There are some specles on the die which I have also seen on Cree ML-E and some other LEDs in this power rating class. The four bonding wires can be easily discerned, because of the a-centric dies embedded in the LED itself the beam uniformity might be very worse.
Performance
25 °C Tsp, unless noted otherwise. In ‚real life applications‘ this values may vary.
Due to the higher thermal resistance and highest CRI these emitters do not deliver as much luminous flux as ‚classic‘ high power LEDs.
- The 3000 K variant reaches 184.3 lm @ 4.22 V at 1,500 mA (6.33 W, 29.1 lm/W)
- The 5000 K variant reaches 281.0 lm @ 4.37 V at 1,500 mA (6.56 W, 42.9 lm/W)
Despite the design and higher thermal resistance, they are quite powerful, with better overcurrent capabilities than other emitters in same design.
- I would recommend a maximum current of 800 to 1,000 mAmps.
Despite the slightly lower thermal resistance of 3000K Optisolis, the reached maximum current at the same test setup is almost the same.
The 5000 K variant has a slightly higher Vf, but overall the efficiency of the 5000 K Optisolis is way better than of the 3000 K variant. If these LEDs are soldered in 4P config on a board together the warm white emitters lit up earlier, like here:
Light quality and use in optics
Because of the two non-symmetric dies this LED cannot be easily used in standard flashlight optics like reflectors, because the beam uniformity is not as uniform you would expect from a flashlight.
Using some type of diffusor (dc-fix or similar) is necessary if you prefer an absolutely smooth light distribution.
I can describe the tint in one simple word: awesome. The color rendition even without measure equipment is very, very high and very natural.
Our BLF member Maukka did extensive color testing of Optisolis in both CCT, shown here (with his permission).
Optisolis 3000 K test results
Optisolis 5000 K test results
You can find more results and information to the tint also in maukka's thread!
Conclusion
This might be the LED with highest light quality to date.
The Optisolis series are also pretty decent in light flux, and could be overpowered very well, especially for it's design. I did not like the difference in Vf between both CCTs, and the unusual footprint which makes flashlight modding much more complicated. For interior and accent lighting these LEDs are very interesting, especially the 5000 K variant!
Pro
- Very high light quality
- Pretty high maximum current possible for it’s design/type
Contra
- Non-Symmetric dies which has impact in beam uniformity if used in conjunction with optics
- Vf difference in CCTs
- Unusual footprint
Thanks a lot for reading! :)
Greetings, Dominik (aka BLF member koef3)
Mistakes, suggestions or offers / sponsoring of LEDs which I should test next are best sent via PM.