I haven't posted a mini review here in years, but I am excited about the new lights available.
A month or two ago I purchased a Fenix PD20 1x123 and then the LD10 1xAA battery tube. It is my understanding that the heads are the same, so I only have one head.
I just received my Quark AA (1xAA).
Quark's slightly larger diameter switch and complete circle permits a better "candle" tail stand.
Fenix's lanyard attachment works a bit better, but Quark could improve that by machining two slots rather than a slot and a hole (that's too small for many lanyards). I solved the problem by installing a loop of waxed nylon "lacing cord" (for electronic wiring harnesses) and then attaching the Fenix wrist lanyard which I like.
The Quark's AA battery tube is too short for the slightly-long AW 14500s that I got. That was fixed by using the clip-securing ring to lock against the switch to keep it slightly farther out than if it was completely tightened. I did not use the clip, I prefer a short wrist lanyard.
The Fenix Candle can be stretched to fit on the Quark. I wouldn't try it the first time in cold weather.
The Quark's tailcap threads are NOT anodized so you can't easily lock it out as you can the Fenix, but the harder switch and full surround reduces the need.
While some have complained about the stiffness of the Quark switch, I think it's fine once you get the feel of it and it's less likely to be activated by something in your pocket.
The SOS in both lights could be faster and better formed. It is painfully slow in both lights.
The beacon in the Quark is odd in the way each pulse ramps up and down, the Fenix TK40 is better in that regard. I think the beacon starting at full output gains more attention, but I'm not sure of the research that went into this.
The flash entering moonlight mode on the Quark may be useful to let you know it turned on but in the dark, it's annoying.
I think I'm still planning to get the 2AA Quark tube so that I can take advantage of the extended run times when necessary.
Light output and estimated runtime:
The light output of the two lights is quite similar, with the Quark having a slightly wider coverage before the light falls off to zero (I prefer this).
All light output measurements are with a Meterman LM631. The meter measured lux at 1 metre, which is equivalent to candela output.
Fenix LD10 with Maha/Powerex Imedion 2100 mAh cell:
Turbo: 2200 cd
Max: 1600 cd
Med: 800 cd
Low: 125 cd
One of the challenges with this head is that with Tenergy RCR123A cells, the output is:
Turbo: 3650 cd
Max: 2010 cd
Med: 1400 cd
Low: 1400 cd
It was this inability to use standard 3.7 V rechargeable Li-ion cells that caused me to purchase the Quark.
With a 14500 3.7 V rechargeable, the Quark AA produced the following:
Max: 3700 cd
High: 1750 cd
Med: 350 cd
Low: 70 cd
Moonlight: 6 cd
Using power consumption and available energy capacity, I am currently estimating the run-time on the 14500 Li-ion to be:
Max: 36 minutes
High: ~2 hours
Med: 10 hours
Low: 50 hours (2 days)
Moonlight: 300 hours (13 days)
I did not check the output with the supplied AA alkaline cell, but it appeared to be similar to the 14500 which was what it was supposed to do.
Zebra Light H501
This is a wonderful headlamp. No throw to speak of, but what a clean even beam! The interface is a bit confusing at first, but I can understand why. The lockout is useful and the GITD clip makes it easy to find at night. Love it.
Output with a Imedion 2100 mAh NiMH cell:
High: 50 cd
Med: 11 cd
Low: 2 cd
But the candela output doesn't tell the whole story. There is a LOT of light coming out and the output is pretty much even across the full field. I didn't measure it, but the cone looks to be 75-80 degrees as specified.
The lack of ability to use rechargeable Li-ion cells in the Fenix (and retain the full-range of light output) is one major reason to choose the Quark. The moonlight mode is another. It puts out much less total light in its lowest setting than the Zebra Light H501, despite the candela measurements, above.
There are some minor issues with all the lights.
It is too bad that the Fenix PD20 light is packaged with Tenergy RCR123A cells from some suppliers (who are very nice), but low is important too, as has been discussed here.
The reason I'm interested in the AA form factor is that I usually have a lot of AA cells around for other purposes and I have car-powered chargers for AAs (as well as Li-Ions) but AAs are far more prevalent around here and I don't want to have to stock batteries in case of disaster that don't otherwise get used. I did that for many years in Southern California, and I'm trying to be "greener" here in Ontario, Canada.
For most applications, having two 14500 cells will cover me and in an extended outage, I can give up the peak light output, I suspect.
As an aside, the Fenix TK40 is pretty cool for what it is. It, too, runs on AAs. One of the reasons I got that, too, is its incredibly long runtime on what would normally be medium power levels. No more D-Cell-powered fluorescent lanterns for me. I end up throwing out D cells that are at their expiry date 'cause I don't use them and don't want to risk leakage.
Enjoy. Sorry no pictures.