[Dominik]

Some days ago I get in my hands two headlamps : Silva Alpha 6 (about 349 € / 500 $ ) and Petzl Ultra Blet 4 (about 299 € / 499$)

Here you can see what came out from that meeting


Heads are similar in size, but it is easy to see that ultra is beating the alpha in led’s quantity .

3x Luxeon K2 TFFC vs 6x Seoul Semiconductors SSC P4

But the claimed output doesn't show that:
540 lumens vs 350 lumens


Alloy vs. composite, what will be lighter ? Alphas head weight only 183 g instead 213 g of ultra

Power source – both are using 7,2V Li-Ion packs but they have totally opposite approach to that case.

Silva is using heat shrinking tube and neoprene - battery pack weights 326g and have 6,9 Ah capacity.


Petzl instead is using hard composite case - battery pack weights 270g and have only 4.0 Ah capacity.

Additional equipment.
No extras from petzl, but Alpha is very universal headlamp, in addition to head strap you are getting a clip on helmet mount and a handlebar mount. You can easily convert yours alpha into a bike or a helmet light.


Light output
I was wondering why Petzl is getting only 350 lumens from the Ultra for some time, only 350 lumens from 6 emitters After seeing it for the first time in catalogue I was betting that this lamp is overheating and I was right.


On the left, Ultra on high right after turning on, it is giving about 450 lumens - compared it to my quad Cree - then about 10 minutes later… Everything is clear .

Power consumption and burn time:

Alpha 6

mode  V-in   I-In     P-In  Calculated burn time.
high   6,8   2,060   14,01    3,64
mid    7,1   1,506   10,69    4,77
low    7,1   0,093    0,66   77,32
flood  7,1   0,572    4,06   12,57

Petzl Ultra Belt 4

mode  V-in   I-In     P-In  Calculated burn time.
high  7,3    1,250   9,175   3,13
mid   7,6    0,432   3,292   8,74
low   7,7    0,117   0,903  31,88

So, claimed runtimes are ok, then...

Let’s take it outdoor, there was about 2 Celsius degree outside so both headlamps were pretty well cooled .

On high


On mid


On low


And alpha’s flood (only led is burning) vs ultra low.


Reflective markers are set in a 5 m distance - the light is pointed on 10 m marker.