Forever in search for a good flicker-free GU10 bulb, we came across the Luminus Elite 50w replacement bulb at Costco.  According to the spec sheet it scores very high on the Color Rendering Index.  But, how does it perform otherwise?  Let’s find out.

ADVERTISED SPECS

• Connector:  GU10 (120v)
• Brightness:  400 lumens(~40w equivalent)
• Consumption:  6 watts
• Efficiency:  67 lumens per watt
• CCT:  3,000K (“Bright White”)
• CRI:  > 90
• Dimmable:  Yes
• Make / Model:  Luminus 806918, PLZ2013T3
• Energy Star:  Yes
• Warranty: 4 year replacement

FLICKER AND COLOR

We detected flicker depth of ~35% at a frequency of 120Hz.  In other words, the bulb pulses rapidly between around 65% brightness and 100% brightness 120 times each second.  While flicker at such a high frequency is invisible, it is certainly within the range of contributing to symptoms of those most sensitive.

Advertised color temperature is 3,000K, quite close to our measured color temperature of 3,036K.  We measured a CRI of 92.2 which is within spec of the advertised >90 CRI.  Our spectral-power distribution graph shows a reasonable distribution favoring the yellow and red range resulting in a somewhat warm appearance.

OTHER CONSIDERATIONS

For those not sensitive, this is a very good bulb.  A CRI score of 92.2 is impressive, meaning colored objects illuminated by this light will not appear discolored.  Percentage flicker and flicker frequency are unlikely to cause problems for those least sensitive.  The CCT of 3,000K provides a neutral white suitable for productive areas of the home, like the kitchen.  Efficiency is reasonable at 67 lumens per watt, though still a massive improvement over the 7.5 lumens per watt common in halogen bulbs of the same bulb type.  At an absolute brightness of 400 lumens makes this a proper 50w replacement.  The advertised compatibility with dimmer switches is a bonus, though dimmer wasn’t tested for this review.

Unfortunately, for those most sensitive there are simply too many compromises.  Flicker was detected at a non-trivial depth of ~35%, though we have seen worse in other bulbs.  We much prefer bulbs with no measurable flicker, though in fairness to the Luminus brand, the challenges of including such an effective driver within the small confines of a GU10 bulb may not be commercially viable.  Those sensitive to blue light may be better served by a warmer 2700K bulb.