One of the first things I noticed about the ST6 is
that the anodized finish was a bit different from other lights I have
used. It has a more bead blasted rough finish to it, instead of a smooth
somewhat glossy hard anodizing. I liked it alot due to the fact that it
provided a nice grippy feeling surface. The knurling on the battery
compartment end cap was fairly aggressive and provided alot of grip for
screwing the cap on and off.
I have the 500CW version of the ST6, this is the most powerful
version with a Cool White Tinted LED. Spark also offers a "Neutral"
White version that has a warmer tint, with slightly less lumen output.
The ST6 was about the size I expected it to be
for an 18650 (or 2xcr123) powered light. The weight wasn't bad at all
either. It can feel a bit front heavy compared to other headlamps that
use a separate battery compartment behind the head. But I personally
think that they can be quite bulky at times, and I like the small
portability of an all in one system. The rubber mount for the ST6 holds
the light in place very well, keeping it in place once you rotate it up
or down to the position you like.
As I mentioned above, the ST6 has a nice grippy
surface finish, and the knurling is on the aggressive side. Though this
is not as much a concern with a headlamp. The head strap seems to be
made well and is a typical 2 strap design, with a strap running around
the head, and one over the top. You can adjust both straps to fit you
properly. I found it to be very comfortable to wear even for long
I found no issues with the build quality of the ST6.
The machining is well done, and the threads seem precisely done without
being too tight. The spring contacts for the battery also seem to be
well made, and hold the battery in place very well with no rattles. I
see no problems with the head strap either. The rubber mount seems to be
a bit stiffer and tougher rubber than used on the Zebralights.
One feature I think is pretty neat is the ability to
load the battery in either direction, positive or negative first. The
light doesn't just have reverse polarity protection, it works with the
battery loaded either way. This would be nice in a situation where you
have to change the battery in total darkness, such as caving.
ST6 has 5 output levels, 4 main ones that are cycled low to high by
pressing and holding the switch, and Super Mode that is activated but
double clicking. The switch is very easy to operate, even with gloves.
The battery compartment cap can be loosened to act as a lockout, so that
the light will not accidentally be turned on it just tossed in a
Mode will only run for 5 minutes and then step down to High. This is to
protect the light and the led from over heating, as well as not over
stressing the batteries. In fact, not all 18650 cells can support Super
Mode due to the high amperage draw.
Low mode is just 8 lumens, which is really nice for night
adapted eyes. Too often lights do not have a low enough low mode, and
honestly sometimes even less than 8 lumens with totally night adapted
eyes would be nice.
The beam pattern is a nice mix of spill and hotspot. The
medium sized hotspot fades out to the spill fairly well. I purchased the
ST6 when it was first released, so I did not receive the frosted lens
option which is now included. instead, I used a piece of adhesive
textured film that I have used on other lights. This made the ST6 the
perfect headlamp in my eyes. I prefer a headlamp to have a large hotspot
that fades out very smoothly to a wide flood. I imagine that the
included frosted lens option would accomplish this quite well also.
I noticed no heat issues with the ST6, even on Super
Mode. The light did get a bit hot, but nothing out of the ordinary for a
high powered LED light. The fluting grooves on the head seem to do well
at dissipating the heat.
5 well spaced output levels
Nice fit and finish
Comfortable head strap
Easy to operate
Able to loosen battery cap to act as lockout
May feel a bit front heavy to some users
Super Mode only runs for 5 minutes before stepping down to High Mode
I have used alot of headlamps over the years, but I
have to say that overall this is my favorite. I have some that are
smaller and much lighter, such as my 1AA Zebralight, but as an all
around, can only have one, I would choose the Spark ST6-500CW. I
personally like the all in one setup, I find it to be much easier to
carry or pack with me. I also think that as far as runtime goes, an
18650 cell light is a perfect mix of runtime and size.
I was impressed with the ST6 enough that I ended up
purchasing the Spark SL5 and SL6 handheld lights as well.