I’ll be reviewing the T20T NW in two sections: first, I’ll discuss the light objectively (the facts about the light itself), then I’ll discuss the light subjectively (my impressions about the light's performance when used for specific applications). If you have any other specific applications you'd like the light tested for, let me know and I'll see what I can do.
Below is a video review of the T20T NW. Due to my old image hosting site closing down, I've got new restrictions on image uploads and have replaced the "Construction" section of my reviews with a more detailed video review.
This video is available in 1080p HD, but defaults to a lower quality. To select the playback quality click the settings button (looks like a gear) after you've started the video.
Price: 60 USD
Plus, here's a few shots with some good detail.
The T20T is controlled by it's tail switch, or by loosening and tightening the head. To turn the light on, make sure the head is fully tightened, then click the tail switch. To switch modes you can either loosen and tighten the head, half-press the switch, or click the switch off then on. This will cycle the light to the next mode in the sequence Firefly -> Low -> High.
You can click on any of these shots to see them full size.
Light in Hand
ISO 100, f/3.5, 1/20"
ISO 100, f/3.5, 1"
ISO 100, f/3.5, 2.5"
Submersion: I submersed the T20T in about a foot of water for an hour, clicking the switch a few times during that time, and can find no evidence of water entering or damaging the light.
Heat: On High, the T20T gets hot after about 10 minutes of use, and there is no automatic stepdown, so I recommend keeping it in your hand while it's on high so that the heat can transfer well.
PWM: I detected no PWM on any mode of the T20T.
Drop: I dropped the T20T from about a meter onto various surfaces (including grass, carpet, dirt, and hard wood), and found no cosmetic or functional damage.
Reverse Polarity Protection: The T20T claims reverse polarity protection, so I inserted the battery backwards and attempted to turn it on, then corrected the battery. The light resumed normal function, and I find no evidence of damage.
Over-Discharge Protection: The T20T does not seem to have any over-discharge protection, and doesn't get dim before shutting off, so I recommend charging your batteries frequently if using lions.
All light that we see as white is actually made up of several different colors put together. The relative intensities of the different colors in the mix are what determine the tint of the white we see. For example, cool white LED's have a lot of blue, and warm white LED's have more red or yellow. This measurement was done on a home made spectrometer. The plot below the picture is corrected for the spectral sensitivity of the human eye. Note: the peak in the 900nm region doesn't really exist, it's a piece of the second-order spectrum that's showing up here because of the high intensity of the light source.
Output and Runtime
ANSI FL-1 runtime ratings are the time it takes for a light to fall to 10% of it's original output (counting from 30 seconds after turning the light on).
The vertical axis of the graphs below represents a relative brightness measurement using a home made light box. The horizontal axis is time in hours:minutes:seconds. Runtimes are stated in hours:minutes:seconds. These graphs may be truncated to show detail.
ANSI FL-1 standard for stating a light's throwing distance is the distance at which the peak beam intensity (usually at the center of the beam) is 0.25 lux. I calculate throwing distance and candela (lux at 1 meter) by measuring peak beam intensity at five different distances and using the formula lux*distance^2=constant.
Quick break down:
+ Screw-on clip
+ Firefly mode
+ Near-perfect regulation
+ Tail switch
+ Diffuser included
+ Neutral available
+ Smooth beam
- Slightly too short for my taste
- Very little low-battery warning
The T20T is one of those lights that has done nearly everything right, so much so that I had a hard time finding anything to complain about The first thing about the T20T is it's style. Since receiving it, this has been the light in my pocket whenever I've been in a more formal environment. The titanium just looks so good - it's not too flashy, but has the elegant look that a black hard-anodized aluminum light can never achieve. The design is simple with few markings on the light and little detail work, so that it just looks very tastefully selected. The head has just enough detail on it to give the grip necessary, without beginning to appear "aggressive". This is one of the few modern high performance lights that you can carry or pull out in polite company without making people feel uncomfortable, and that makes it fulfill a very real need.
Aside from it's looks, it functions very well also. The runtime graph is very nearly perfect regulation--there is a very small drop at the very beginning, then it holds flat until the end of the run. This is one of the areas where I had to be really picky, because my ideal run has perfect regulation like this, except with the substitution of about 10 minutes at the end where the output drops to a sort of moonlight level, warning you that your battery is low, and giving you time to find a replacement battery. If the T20T had this, it's output regulation would be perfect in my book. I also think the output levels have been very well chosen. I'm a big fan of Thrunite's firefly modes (I discuss in the Ti3 review how .04 lumens is actually pretty close to what fireflies have been measured to put out), because it's so useful to have a mode to use when you don't want to wake up sleepers or draw attention to yourself. The low mode is what I use for most night-time around the house objectives, and the high mode is good for short bursts when I'm outside and need a look at something a bit further off. This is mostly an up-close light of course, due to it's size and power source, but it's good to have that option if you don't have another light with you. The max output is a bit lower than stated in the specs, but this is to be expected with the substitution of a neutral emitter.
That brings up my one other picky complaint-- the T20T is just a bit too short for my taste. As a rule, I don't put CR123 lights on my keychain, because I carry my keys on a clip on my belt most often, and even the slimmest CR123 is just too thick, so that position is exclusively reserved for AAA lights. That means as a CR123 light, the T20T is a pocket light for me. In this position, a little extra length would make me feel more secure that it's not going to slip out without my notice. In addition, my hands are pretty large, so it would actually be more comfortable for me to use the T20T if it was a bit longer. For this reason, I think the T10T would actually be the perfect size for my taste, because it runs off a AA battery. The only drawback with the T10T is that Thrunite's specs claim it's driver can only handle up to 3V, so a 14500 lion to boost the output wouldn't be an option. But anyway, as a pocket light, the T20T does just fine, because it turns out it's clip is actually pretty secure. I took mine off and bent it inward a bit to increase the tension, just to make myself feel better. I've included a picture of it riding pocket duty here:
The clip is very sturdy, and after adjustment I'm very happy with it's tension. I'm happy it's a screw-on clip, because I don't have to worry about the clip popping off, but it's pretty easy to get off for anyone who wants to give the T20T some keychain duty.
One of my favorite things about the T20T is the tail switch. Many compact lights ditch the tail switch as a bid for more compactness, because a head-twisty interface takes up less space. However, this can leave them hard to work, especially on slick materials like titanium, so I'm glad Thrunite went with the clicky tail switch here. Being titanium, there is a bit of roughness to it's action (more so than a switch with a rubber boot) as the titanium slides across titanium, but it's actually much less than other titanium lights I have, so that it's not unpleasant at all. Thrunite also gave the T20T head-twisty interface as an option, but I'm not sure why they bothered. I don't know anyone who says they prefer that except for the shorter length, which doesn't apply to a light that also has the tail switch. My only thought is that you'll be able to change modes with either underhand or overhand carry without changing your grip, which is nice for a clumsy guy like me using a small light like this. The grooves on the head provide plenty of grip for twisting the head, should you want to.
The beam quality with the T20T is pretty great too. The beam is nice and smooth due to the textured reflector, and I really appreciate the option for neutral tint, which just adds to the overall classiness of the light in my opinion. It's also got the diffuser wand which I believe is a standard accessory, and that makes a great combo with the ability to tailstand (or use the lanyard to hand from a ceiling) and fill the room with some soft light. The diffuser fits on snugly, and also adds to the overall length of the light, which my large hands appreciate.
Overall, the T20T is an excellent high-end light with very few flaws. If you're looking for a light that you can use in more formal situations, if you're a collector of titanium lights, or if you just want to foray into the titanium world without breaking the bank, the T20T is an excellent option, that performs just as good as it looks. With the neutral version costing the same as the cool version, there's no reason not to go all the way and get a great tint too
Long Term Impressions
I'll fill this part in after carrying the light for a while. If nothing get's added here, either I find nothing else worth noting about the light, or I end up not using it often.