Bocian Citizen COB 6 W LED spotlight bulb review (CRI97, GU10)

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Bocian Citizen COB 6 W LED spotlight bulb review (CRI97, GU10)

Bocian sent me three of his Citizen COB based spotlights for testing. They come in three variations, 2700, 3000 and 4000 Kelvin, which covers the whole range of Citizen COB model number CLU028-1201C4 (click for datasheet).

They are relatively low power at 6.5 watts but with a good power factor of >0.9.

All the models have great color rendering. The 3000 K sample of mine was a bit yellow, but the 2700 K and 4000 K were great. The beam is wide and even, so not really a spotlight. Here’s the essential data recorded during testing:

Beam profile

I measured the beam profile with only the 4000 K version and assumed the other two are pretty much identical since they use the same COB family with an identical reflector.

The light is very floody with a 96° beam (1% lux) and 1.4 cd/lm. To the eye it looks quite evenly lit other than the very edges, since the falloff is very gradual.

There’s hardly any tint shift. While it may look harsh on the edges in the graphs, the intensity has already fallen down to almost nothing and can only be seen on closer inspection on a white surface.

I’ve also included the 3-step ellipses on the tint chart. The whole beam of the 4000 K version falls inside the 3-step specification, but the 3000 K light was for some reason a bit off. 2700 K one again is very similar to the 4000 K but even closer to the black body line. In other words it’s a perfect incandescent replacement.

CRI data


There’s no PWM but some AC induced 100 Hz flicker, which may be seen in some situations. For example when waving a lightly colored rope or stick in a room lit by the lights. Flicker snob index of ~10% means that in practice it is likely never noticed unless you know how to look for it.

With a modulation of 33% it is certainly more noticeable than an incandescent flicker, which usually has a modulation depth of about 10% in normal room temperature. So if you are one of the few who are bothered by incan flicker, you’ll notice this one for sure.


These are very pleasant general lighting bulbs. I just wished they were available with the more common E27 socket, but adapters don’t really cost much. The $12 price is good. 500 lumens with almost perfect color rendering and low power consumption is better than pretty much anything you can find in you local hardware store. The 2700 K model is a fantastic incandescent replacement and with an efficacy of 75 lm/W it’s about seven times better for your wallet than your basic filament source.

Edited by: maukka on 02/02/2019 - 04:57