Thanks for the kind words everyone; It's appreciated, and I'm glad you've found my review interesting
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Thanks BigC and GeoBruin! I'll do my best to take lux measurements of the X10 soon. The problem is that I don't really have a good place to test @ 5 meters
. GeoBruin, unfortunately I don't have a TK35, so I can't compare reflector size of the X10 to that of the TK35 for you.
Thanks for the kind words, Selfbuilt. Using a fan while testing lights that are not thermally regulated is definitely a good idea, but my reasoning for the freezer pack method was simply to show what the light is capable of if you can keep it cool enough. The hand heat sinking method was done because it's commonly implemented during actual use by many here on the forum, and the 'no additional cooling' method was used to show the lower end of this lights output, and could easily represent the output of the light if someone where to sit the light on a stand, etc.,and use the light hands free, although I'm sure my two fingers were pulling some heat from the light during use so it's not exact. And the 'normal' mode is the mode I think most will be holding the light when in actual use, but unfortunately I didn't test the S12 using that method......
If I had more time I'd test this light using a fan, but I simply don't have time; at the moment I'm quickly falling behind on reviews of other lights that I've committed my time to.
Your question about the freezer pack method is a very good question, and I'll do my best to answer that for you. As I'm sure you're aware, both the S12 and X10 have thermal regulation (and current regulation). This works because the light is designed to deliver a set amount of current until the light reaches a predetermined temperature (usually well below the thermal limit of any component used in the light). When said temperature is reached, drive current to the emitter is reduced to gain a reduction in operating temperature. If you've noticed the spikes in some of my lumen graphs, that's what's happening at those points. The light throttles current back to cool the light, which in turn causes a slight drop in lumen output until the light's temperature is reduced enough to protect the light, then current is reapplied until it reaches the predetermined temperature again, then the light repeats the process all over again.
When using the freezer pack method, the light doesn't heat up enough to require a reduction in drive current to cool the light because the freezer pack is keeping the light below the predetermined cutout temperature. Because of this the lights driver delivers the max predetermined amount of current to the emitter. Consequently this causes the battery to deplete quicker because the light is consuming more energy from a source that has a limited amount of energy until it needs to be recharged. Now to explain the difference between both lights during the freezer pack method. As you know the S12 uses the SST-90 emitter and the X10 uses the new XM-L emitter. Well the XM-L is more efficient than the SST-90 emitter, therefore it produces more light output for a given, and equal amount of drive current, but it's limited to 3A max drive current while the SST-90 is limited to 8 or 9A of drive current if memory serves me correctly. These emitters can be, and have been driven harder by individuals who want the most light they can get from the emitter, but that's another topic for another thread.
Anyhow the SST-90 is being driven harder than the XM-L to produce its highest output. I believe I've read reports from individuals stating in the 5A range at max drive current, but I'm not certain about that. I do know that the XM-L is being driven at less than 3A drive current, and if I had to guess, I'd guess in the 2.6A range. Now even if the XM-L were driven at 2.5A and the SST-90 were driven at 5A (twice the current), you still couldn't guess that the XM-L light would run twice as long because it's more complicated than that because of emitter voltage forward differences between the two emitters (volts x amps = watts), and the higher the emitter voltage forward, the more energy it consumes from the battery and the quicker the battery will be depleted. So you would have to take voltage and current measurements simultaneously to actually calculate how much power or wattage each different emitter is consuming, but we don't really have to know that exactly because we know that the SST-90 is consuming more, and it shows by its drop in output on the lumen output graph.
So after that long, drawn out response
....haha..... the reason you see the S12 dropping in lumen output quicker than the X10 during the freezer pack method is because of the S12 depletes the battery quicker than the X10 does because they're both being driven at the max predetermined amount of drive current. So in the freezer pack method, the output is no longer limited or decreased because of temperature limitations, but because of battery capacity limitations. Both batteries (X10 only and S12 batteries) are very close in capacity, so the one that drains the battery capacity at a quicker rate will dim quicker than the other. Hope this is accurate, and helps you better understand what's going on. Sorry for the drawn out way of explaining....:tired:lol...