User SunLike from sunlikelamp.com sent me a Remez E14 LED bulb for testing.
Store page: http://sunlikelamp.com/index.php?route=product/category&path=59_105
Manufacturer website: https://remezlight.com/en/production/light-for-home/led-bulbs/led-s37-5w-3000k/
The main specs by the manufacturer:
–3000K color temperature (also available in 5000K)
-CRI (Ra) 95
-SunLike SMD 3030 emitters
–300 lumens
–5W power rating (also available in a 7W version)
-Power factor >0.5
-AC voltage range of 170-260V (also available in 110/120V)
-Not dimmable
–30000 hour lifetime
–5 year warranty
The bulb is also available with an E27 base in 5 and 7 watts. Review here.
Measurements
Measurements were made in a 50cm integrating sphere with an x-rite i1pro spectrometer after the bulb had warmed up for 1 hour. Intensity (lux at 1 meter, candela) was measured outside the sphere at 50cm.
The bulb was connected to mains power which at the time of testing was at 220V.
Output at 1 hour is 296 lumens. Manufacturer claims 300 lumens. The output drops 21% during the first hour from 377 lumens at turn on.
The bulb is very light so there’s not much heatsinking, which explains the long winded drop in output. Thankfully the power of the bulb is not very high either so it doesn’t get exceedingly hot, but hotter than the E27 version at 79 degrees celsius.
Power consumption was measured at 4.8 watts at 220 volts with a low power factor of 0.59. Total bulb efficacy is low even for a high CRI warm light source at 61 lumens per watt.
Maximum output is reached immediately. Light output in lumens was plotted over one hour. Output is stable after the intial warmup.
Color rendering
The CRI data was measured integrated after a 1 hour warmup in an integrating sphere.
Color rendering is excellent at CRI Ra of 97 and R9 of 94. TM-30-18 fidelity index Rf of 95 and gamut index Rg of 104 are also very good. Just like on the 5700K SOL bulb, there’s three distinct but small humps in the spectrum at different wavelengths (450, 520 and 620 nm). There’s no near UV content.
Visually the light is pleasantly warm with a slight rosy tint to it. The 3000K color temperature makes it bring out colors just a bit more than a very warm candle like lamp like the Bedtime Bulb.
Load IES TM-30-18 Color Rendition Report by clicking on the thumbnail:
CGATS CRI Data file:
https://pastebin.com/Yws1Yg44
Color temperature and tint
Tint is below the black body line but visually neutral. Remember that when LEDs heat up, their duv value almost always decreases and becomes less green/yellow. This was measured after 1 hour in an integrating sphere so the tint has already stabilized.
Tint is even around the bulb thanks to the diffuser. The color temperature gets only slightly cooler when moving to the side, but the near constant duv value makes it not distracting.
Flicker
The switching frequency of 42kHz is not visible to the eye. The snob index of 0% guarantees that it’s easy on the eyes. High frequency flicker is probably not visible to a camera at high shutter speed either.
The light is also stable on a noisy AC source or a simulated/stepped sine inverter. However, there’s a bit more audible buzz with a stepped sine wave inverter than on the E27 Remez. It’s far from obnoxious at a meters distance though.
AC power draw
Current is drawn in short pulses 100 times a second as the input voltage gets high. There’s no power factor correction which results in a power factor of 0.59.
Cyan line: mains line voltage
Yellow line: current draw of the bulb
Violet line: power draw (voltage * current)
Verdict
The Remez warm white bulb utilizing SunLike LEDs has a very similar spectrum to an incandescent bulb. Other than the low total efficacy of about 60 lumens per watt and mediocre heatsinking it performs very well. It is also very cheap considering the quality of light at $6 or 5.40€ a piece. There’s no visible flicker to the eye or to a camera and the bulb turns on immediately at full power.
Please note that the test was done when the bulb was brand new. I can’t guarantee that they will perform similarly after months or years of use.
. My first bulb now achieves a Duv of 0.0000 at operating temperature, and the CRI Ra is up from 96.6 to 97.8.
How many of the E27 3000K do you have available from stock?