The DT-E1.0 is DarkTort's premiere product based around their modular concept of flashlights. Right up the front of the head is a prominent and thick stainless steel, crenellated bezel. In addition to allowing light to shine through in case the light is placed head-down while on, it should also serve well in protecting the front end from impacts and hold up well to superficial damage. A double coated, impact resistant glass lens sits behind the bezel. The aluminum reflector used as a fine and consistent texture which has a well polished surface finish. The LED which sits at the bottom of the reflector cup is well aligned, just slightly off to one side. Looking at the head from the rear you can see that none of the electronic components or PCB are exposed. Instead, they're house within an red anodized aluminum case. There are four brass colored electrical contact points which can be seen. The middle one is for the "+" battery contact, this is slightly raised so flat-topped 18650 cells will work just fine. The three others are spring-loaded contacts which control the mode changing mechanism of the light. The top half of the head has a clean design with shallow flat faces machined all the way around, they will somewhat serving as an anti-roll feature. The bottom half of the head has cooling fins machined on which should help with heat dissipation, and also adds a cosmetic touch. While DarkTort advertises the light as being modular, having interchangeable modules, I couldn't disassemble the head to remove the LED module.

Update: 2009-01-05
The LED module and glass lens within the head is in fact accessible by unscrewing the bezel.

The battery tube has a band of knurling in the region, though it's really narrow and probably doesn't help with grip much. Along this knurling are four flat faces, two of which have branding text printed on. There are also markers showing the direction to twist the battery tube for switching between modes. Just behind the knurling is a slightly raised ring which helps when the light is held in a cigar-style grip. The entire flashlight, aside from the stainless steel bezel, is coated in Type 3 anodizing which should provide good surface durability. The anodizing is glossy and on the smooth side, this may be a factor if you have greasy hands. Surface finish is very well done with no signs of fine residual machining lines at all. Threads on both ends of the battery tube are anodized, loosening the tail cap allows the light to be locked-out to prevent accidental activation. The threads mate well with the head and tail cap with no cross-threading or grinding encountered during tests. A rubber o-ring sits on each end as well to provide moisture seals. Both the threads and o-rings came well-lubricated which was nice. The battery tube has walls of average thickness, and it's interior diameter is wide enough to easily accommodate protected or unprotected 18650 cells. A peculiar thing I noticed is that the battery can only be inserted from the front end by unscrewing the head because the interior of the battery tube has a narrower section towards the rear. The tail cap also has a narrow band of knurling right around its front edge which seems to serve purely a cosmetic purpose. Shallow flat faces are machined around the middle region of the tail cap which are similar to those on the head. Right at the end of the tail cap are four wide holes for lanyards attachments. The switch used is a forward push button which allows for momentary activation. It has longer than average travel, you have to push the switch further than most other lights before it engages. It is also on the stiff side though still provides a positive tactile and audible clicking feedback. The switch cap protrudes out the tail end so the tail standing isn't possible.

If you're unfamiliar with any of the terms used in this review, click here for explanations on common flashlight related vocabulary.

The DT-E1.0 has a pretty straight forward High/Low user interface with the addition of a Strobe mode. The mode at which the light activates is based on the position of the head. By default, a loosened head activates the Low mode, while a tightened head activates the High mode. The tightened position can to be configured to function either High or Strobe mode, this is done performing a loosening and tightening of the head within 1 second. The setting of the tightened state is memorized even after switching off the light. The loosened position cannot be changed and is always fixed to Low mode. Both High and Low modes are constant current regulated which means you won't encounter any PWM effects. Also, the light actives perfectly silent on all modes with no signs of high pitched sounds which may be present is some other multi-mode lights.

The beam profile produced by the DT-E1.0 has a narrow hot spot which has a bright corona right around it. The spill beam has a subtle hexagonal shape as a result of the high, crenellated bezel. Color temperature is on the cool side with a slight violet tint, especially noticeable at close distances on Low mode. Overall the beam profile is smooth, though it has the common dark ring right around the corona which is seen on most Cree XR-E based lights.

Do take note that the DT-E1.0 only runs on a single, 3.7V li-ion 18650 cell, do not use 2x CR123 or 2x 16340 configurations because it only supports a voltage range between 2.7V to 4.5V. Regulation isn't maintained well on High mode as can be seen from the sloping on the plot. On the other hand, output intensity on High mode is above average. Low mode manages to maintain regulation much better as can be seen from the almost perfectly plot. Notice that at the end of either of the graphs, output drops sharply. Take note that the light doesn't actually switch off at this point, it goes into a sort of "moon mode" which has an extremely low intensity which is less than 1% of the High mode. This happens as a warning feature when the cells voltage level reaches 3.0V, it will then totally switch off when the voltage drops to 2.7V to protect the cell from damage due to over-discharge in case an unprotected 18650 cell is used.

My runtime and output test results seems to be quite different from the manufacturer's rated data provided on their web site. I failed to achieve a lux measurement for ~16000 at 1m on High mode, or the ~18 hour runtime on Low mode which was advertised.

The Good - Solid build quality and great finishing. Nice additional design components such as the thick stainless steel bezel and raised ring for cigar-style grip. Built-in electronic protection for li-ion cells.

The Bad - Doesn't achieve advertised runtime or brightness by quite a large margin. Runtime on Low mode is below average relative to its output intensity.

The Relative - Beam has a cool color temperature with a slight violet hue. Uses a forward push button switch. Is not able to tail stand.

Head (front view).

Head (side view).

Head (rear view).

Battery tube (front view).

Battery tube (side view).

Battery tube (rear view).

Tail cap (front view).

Tail cap (side view).

Tail cap (rear view).