Product Reviews

Reviewed: LED GU10 lamps

Nowadays, it’s nigh on impossible to buy a luminaire from the DIY sheds or a high street retailer which doesn’t have a GU10 cap.

Remember that these are mains-voltage lamps and don’t need a transformer. 12V lamps seem to have had their day as far as the mass retailers are concerned. We reviewed GU10 lamps over three years ago and there have been lots of changes in the market since then. This review includes newcomers plus some of the established names in the market.

Only a few of the lamps have a high power factor. The best was Verbatim at 0.96. The poorest was the Crompton at 0.41. Why does this matter? Because it means that you are drawing more current than might appear from just looking at the wattage. An electrician complained to me about this issue because he had to resize all his fuses in a (large) domestic house purely due to poor power factor.  See our explainer on power factor HERE.

Before you buy the lamps, you should check what the beam looks like. None had a clearly distinct edge and many didn’t have a smooth gradation of light from the centre to the outside. All the lamps had very similar beam widths. Subjectively, the beams appeared wider than the figure quoted on the box.

We were pleased to see that, generally, the performance was as claimed, some considerably better. This may be down to the Lux team only choosing reputable suppliers – there’s not much point in us writing about a lamp that we know you shouldn’t even consider buying.

Note that we tested just one lamp from each supplier. There are always tolerances in manufacturing and so the lamp you buy may not perform exactly as the one we tested. However, these lamps are made by the million; it would be surprising if they varied that much.

Our testing was done at the independent Lighting Industry Association laboratories at Telford, England. They measured the total lumen output. Packaging regulations say that for lamps of this type, the manufacturer should also quote the lumens contained in a 90-degree beam. Not all the manufacturers did this and this can lead to confusion in the market because shoppers cannot compare like with like.

We also tested the lamps visually by shining them at a plain, matt white, wall. Our comments are purely subjective but do tell you something about what the actual beam of light looks like.




This lamp emitted almost 10 per cent less light than is claimed on the packaging. It also omits to state the lumens contained within a 90-degree beam. The packaging also understates the power consumption, albeit by only about 6 per cent. However, the lamp does produce a nicely shaped beam with a fairly distinct edge. In terms of lit appearance, this is one of the better lamps.



Integral LED

This is another GU10 with a high colour rendering index, CRI, of 98. It really does make a difference in domestic and hotel locations. The beam is broadly circular and has a soft edge. It’s a nice looking lamp.





This produced a smooth beam with no shadows or hot spots. It appeared broader than the 45 degrees stated on the packaging but this is a comment that would apply to all of the suppliers. You get slightly more lumens for slightly fewer watts than stated on the box.




This Osram lamp from Ledvance ought to impress more than it does. It emits more light than stated on the packaging, it has a CRI of 90 and an efficacy better than most high colour rendering lamps. It also has a respectable power factor of 79 per cent. Look closely at the beam, however, and it is not all smooth. There are several patches of warmer light within the beam. They become more noticeable the longer you look. The cause may be due to the multiple chip sources behind the heavily-prismed front lens.




This produced the highest lm/W and emitted considerably more lumens than stated on the packaging. However, look closely at this lamp and you can see four individual light sources. These account for the odd-shaped beam. Its edge is poorly defined and it looks approximately round but with four bulges.



Philips Expert Colour

What sets this lamp apart from the rest is the high colour rendering index, CRI, of 98. Combined with the nominal 2700K colour temperature it looks great in any hotel or retail location. It also has a long life.It has a long life and high power factor.




Supermarket brand

There was a choice of GU10 lamps in our local supermarket. Even so, the more expensive ones were still only £2.50 (US$3, €2.8) each. The measured light output was 8 per cent higher than claimed on the box. However, like some other lamps, the beam was a slightly odd shape and it had indistinct edges. The rated life was the lowest of those tested.




Tungsram is the lamp company formerly known as GE Lighting in Europe. It emits 14 per cent more light than claimed and has a high colour rendering index, CRI, of 97. The beam is nice and uniform and has a soft edge. It also has a power factor higher than most at 0.87.





This had the highest lumen output of any of the lamps and almost the highest efficacy. If you need a lot of light, this is the lamp to choose. However, it is a very cool 6700K. The beam, itself, is very woolly with no clear edge.




This has the second highest lumen output and highest power factor. It also has a CRI of 91. There’s a decent, clean shaped beam without any spots or striations. It’s an all round high performing lamp.



  • See the latest LED GU10 lamps at the LuxLive 2019 exhibition. The show takes place at ExCeL London on Wednesday 13 November and Thursday 14 November 2019. Entry is free if you pre-register. For more info, click HERE