NiteCore D20 Review - 2xAA - RUNTIMES, BEAMSHOTS, DETAILED PICS and more!

selfbuilt

Flashaholic
Joined
May 27, 2006
Messages
6,936
Location
Canada
Warning: Picture and text heavy!

Reviewer's Note: The NiteCore D20 was provided for review by Edgetac (NiteCore).

The NiteCore D20 is the latest offering in the piston-drive "SmartPD" family from Edgetac (NiteCore). Although a lot of the basic design and circuit functioning is similar to the 1AA D10, this new 2AA model features some significant build differences.

The main distinguishing features of all the NiteCore Smart PD lights is their simple continuously-variable interface, and innovative McGizmo "piston drive" design that doesn't use a clicky switch. For a comparison to the 1AA D10, please see my earlier reviews:
NiteCore D10 & EX10 Reviews: RUNTIMES, BEAMSHOTS, COMPARISONS & more!
NiteCore Golden Dragon Plus D10 & EX10 Reviews: BEAMSHOTS, RUNTIMES, etc.

D20-1.jpg


The light comes in a sturdy hard cardboard box with magnetic closing flap. The pocket clip was already attached. Along with the light and clip come a manual, warranty card, good quality wrist strap, extra o-rings, extra clip screws, and a mini-Allen key for the clip screws.

Approximate retail price: $70 USD

D20-2.jpg

D20-3.jpg


Here is how it compares to the competition:

D20-0.jpg

From left to right: Duracell 1AA alkaline, NiteCore D10, NiteCore D20, Fenix L2D, Olight T25, ITP C8 Tactical, JetBeam Jet-I PRO EX V2.

D20 Weight: 109.3g
D20 Dimensions: Length: 154.0mm x Width: 25.0mm (head), 23.2mm tail (without clip)

The obvious build difference on this 2AA version is the heft – the light is surprisingly bulkier than the 1AA model. :eek:oo: Although well balanced and comfortable in the hand, this light is definitely one of the most substantial in the 2AA class. The bezel is wider than the 1AA model, and the head unit has heatsinking fins at its base.

D20-4.jpg

D20-8.jpg


One of the most obvious changes is the introduction of the clip at the tailcap, with its stainless steel clip holder and retaining ring. Edgetac includes a mini Allen key, but a 3/32nd hex screwdriver will also fit. The tailcap retaining ring should reinforce the aluminium in this area, and increase long-term durability. :twothumbs

Unlike the 1AA version, the piston cannot be removed from the open end of the body tube (i.e. near the head) – if you want to access the piston, you need to remove the clip and unscrew the piston opening retaining ring (you’ll need a pair of tweezers or snap-ring pliers). Not that there is any real reason to do so, unless you want to check the lube status of the piston o-ring.

D20-9.jpg

D20-5.jpg


As you can see in my disassembled pics above, NiteCore is still using a lot of the high-viscosity blue-colour lube on the o-rings. :shrug: Although not causing a problem on this sample, a number of the D10/EX10 lights have issues with “sticking” pistons with this lube. The problem is easily solved after disassembly by a quick wipe off of excess lube, or addition of lower viscosity lube, like PTFE (i.e. Teflon, like from the Radio Shack Precision Oiler)

UPDATE: I find the PTFE lube wears off after a couple of weeks, leading to a "clinking" sound when the bare metal piston meets the aluminum body. I am now trying a little of the more viscous Nyogel 760G, which seems to be working well. Wouldn't normally be a problem to just re-lube periodically, but having to disassemble the clip and retaining ring on the D20 each time means you need to have tools with you.

The purpose of this re-design quickly becomes apparent – the light has a fully functioning tailcap lock-out feature now. :thumbsup: Previously, you could partially lock-out the light by significantly unscrewing the head – making it harder for the piston to engage. But this was not a true lock-out – the piston drive could always be engaged with enough force. Now, the piston can only travel so far up the battery tube, so once you unscrew the head pass a certain point, the light cannot be engaged. Well done.

Fit and finish is excellent on my samples - lettering is very clear and sharp, and anodizing is flawless. Note the knurling on all the NiteCore Smart PD light is more aggressive than pretty much any other Chinese light maker I've seen. Still not quite as severe as Surefire lights, though.

D20-6.jpg

D20-7.jpg


The head/reflector has been redesigned from the D10/EX10/NDI, with a wider and deeper reflector with a new stainless steel bezel ring. Despite this deeper reflector, throw is not increased as much as you might expect (scroll down for a throw/output comparison). My sample came with a Cree Q5 emitter, as you can see.

D20-10.jpg

D20-11.jpg


I've opened the head up to show you the insides - it comes apart fairly easily by unscrewing the bezel retaining ring (i.e. pressing on it firmly with a soft cloth). You can see the spring on the light engine. It all fits together well, so there's no real adjustment you can make. The reflector has a nice groove/lip to help hold the o-ring, so re-assembly is a snap.

Piston Drive & User Interface

Please see my NiteCore D10/EX10 review for a detailed discussion of how the basic Piston Drive mechanism and UI works.

Simply put, the batteries sit inside the piston tube, and switching occurs entirely in the head (i.e. the current path is through the piston sleeve and not the body). The contact ring in the head is spring-mounted, and in combination with the MCU can produce different modes and features depending of degree of force applied to the piston. This innovative design also allows you to utilize the light in a couple of different ways (i.e. as both a "twisty" and "clicky" light).

The UI is actually quite straightforward and easy to use. For a good instruction on how to use it, see 4sevens’ D10 video guide here:
http://www.youtube.com/watch?v=irqhuV8Xo_A

So what’s new with the circuit? One welcome change is that auto ramping in the reverse direction after using the shortcuts to Min or Max now works. :twothumbs On the 1st generation SmartPD lights, you needed to press and release and press again to get it to start ramping in the reverse direction after using a shortcut (double-click for Min, click-hold for Max).

Another change has been to increase the number of discrete output states from 100 to 256, according to NiteCore. As a result, I would have expected a longer ramping time, but NiteCore has kept the total ramp length down to about 6-7secs, which is just a second longer than the D10/EX10.

D20-Ramp.gif


If anything, ramping is even more visually-linear now than it was before. But I find I rather miss the slower initial ramp at the lowest outputs (i.e. the D10 spends more time there, proportionally-speaking).

Comparison Beamshots

Both lights are on 100% on Sanyo Eneloop (~2100mAh), about 0.5 meters from a white wall.

D20-Beam1.jpg

D20-Beam2.jpg

D20-Beam3.jpg


As you can see, the beam profile is quite different. Gone on the D20 is the typical dark Cree ring around the hotspot – instead, you can see the D20 hotspot is a lot broader and more diffuse. This relative “defocusing” of the hotspot gives you less throw than you might expect for a bigger reflector. Overall spillbeam width is slightly narrower as well now.

For detailed comparison to its class of 2AA lights, I’ve rounded up the usual suspects:

D20-0.jpg

From left to right: Duracell 1AA alkaline, NiteCore D10, NiteCore D20, Fenix L2D, Olight T25, ITP C8 Tactical, JetBeam Jet-I PRO EX V2. Not shown is the new Fenix LD20.

All lights are on 100% on 2X Sanyo Eneloop (~2100mAh), about 0.5 meters from a white wall.

AA-Beam1.jpg

AA-Beam1B.jpg


AA-Beam2.jpg

AA-Beam2B.jpg


2AA-Beam3.jpg

2AA-Beam3B.jpg


As you can see, the beam profile is again quite different from the typical Cree pattern. Personally I rather like this more diffuse hotspot, but those looking for greater throw will be disappointed.

Testing Method: All my output numbers are relative for my home-made light box setup, a la Quickbeam's flashlightreviews.com method. You can directly compare all my relative output values from different reviews - i.e. an output value of "10" in one graph is the same as "10" in another. All runtimes are done under a cooling fan, except for the extended run Lo/Min modes which are done without cooling.

Throw values are the square-root of lux measurements taken at 1 meter from the lens, using a light meter.

Throw/Output Summary Chart:

D20-Summary.gif


On the face of things, it looks like the D20 is definitely brighter on max than the D10 – as you would expect for 2AA light. As previously mentioned, throw is increased, but not by a large margin.

In comparison to the its 2AA brethren, the D20 is toward the high end in terms of max overall output – but my Fenix L2D and LD20 are both brighter. However, the D20 is capable of the lowest output level of any of my 2AA lights. :thumbsup: Throw of the D20 is also the lowest of the 2AA lights.

Output/Runtime Comparison:

D20-Hi-Ene.gif

D20-Med-Ene.gif

D20-Lo-Ene.gif


There are no surprises here – the D20 is a consistently good performer at all output levels. :)

D20-Hi-Alka.gif


UPDATE: I've done a non-lightbox runtime of the D20 on Low on duracell alkalines and got just over 10 days of continuous runtime. :eek:oo:

Among the continuously-variable lights, the D20 performance is very consistent with the ITP C8 lights, and more efficient than the JetBeam Jet-I PRO EX V2. However the D20 is not as bright on max or as efficient overall as the current-controlled Fenix lights (the latter point is to be expected on a PWM-based light).

Potential Issues

The only significant issue I’ve observed in testing is the amount of pressure needed on the piston to keep the light ramping smoothly. Even after cleaning and re-lubing, the force required is definitely more than my D10/EX10 lights. To be certain, the original SmartPD lights required some getting used to in this regard, but this one is definitely even more of a challenge.

As for grip, I like the new body design for over- or under-handed use (i.e. thumb on the piston). Although this design includes some built-in finger grips for a cigar hold, I think you would find it difficult to balance and use the light that way (especially for ramping or rapid clicks).

Haven’t had a chance to really test out the clip in actual usage, but I wonder how secure those screws will hold it the long-term. Time will tell how well this feature holds up.

UPDATE: Proper level of piston lubrication can also be an issue - which requires the use of tools to remove the clip and retaining ring to re-lube. I'm currently trying Nyogel, since I find the PTFE wears off after awhile.

General Observations & Preliminary Conclusions

The D20 is a welcome addition to the NiteCore SmartPD family of lights. I’ve always had a soft spot for 2AA lights. :)

In terms of circuit design, the D20 is definitely an incremental improvement. The automatic reverse ramping and increased output states are positive bonuses. Same goes for some of the new build differences - the pocket clip, stainless steel retaining ring, and piston lock-out features are all useful new additions. I imagine we will start seeing these features in the other members of the SmartPD family as well. :thumbsup:

Overall, I like the sturdy design of the D20 (except for stiffer piston feel). But one of my favourite aspects of the D10/EX10 series was their slim-lined design. Those lights were among the smallest lights of their class, whereas the D20 is one of largest. :shrug: If you are looking for a similarly minimalist 2AA light, you will have to look elsewhere.

The reflector design is interesting – this is one of smoothest Cree beam profiles I’ve seen. But unlike shallow reflectors (which smooth out rings but produce a wide and dim spillbeam), this deep reflector produces a more even (but narrow) spill output. I will need to play with it more before deciding how I like it – but my experience with the LiteFlux LF5 (which has an even narrower spillbeam) tells me you can get used to just about anything. For a general purpose light, removal of the dark Cree rings is a definite plus – just don’t expect a big thrower here.

As always, you need to assess what features matter to you in any given class of light. Now that a number of 2AA lights are on the market, I plan to do a round-up comparison review of this group soon. Stay tuned …
 
Last edited:

adirondackdestroyer

Flashlight Enthusiast
Joined
Oct 31, 2005
Messages
2,018
Great review Selfbuilt. I received my D20 around a week ago and have been waiting for your review (as you know :grin2:).
My only complaint is that I think it ramps up too quickly at the very beginning. It ramps down much slower than it ramps up. Or at least that's what my eyes are telling me.
Are you planning on doing a runtime test on the lowest setting? I'd love to know how long this badboy would run on the lowest setting with two Energizer Lithiums. I'm guessing 165 hours or so.
 

EngrPaul

Flashlight Enthusiast
Joined
Sep 28, 2006
Messages
3,678
Location
PA
The D20 is the classy indoor performer of the group. Definitely worth showing off to friends and enjoying around the house on a regular basis.

As always, I appreciate the excellent pictures, feature description, comparison to other similar lights, and accurate runtimes.
 
Last edited:

gswitter

Flashlight Enthusiast
Joined
Apr 26, 2006
Messages
2,586
Location
California
The purpose of this re-design quickly becomes apparent – the light has a fully functioning tailcap lock-out feature now. :thumbsup: Previously, you could partially lock-out the light by significantly unscrewing the head – making it harder for the piston to engage. But this was not a true lock-out – the piston drive could always be engaged with enough force. Now, the piston can only travel so far up the battery tube, so once you unscrew the head pass a certain point, the light cannot be engaged. Well done.
Interesting.

This change could also address a minor issue I've had with the McLux III PD's. There has to be enough of a gap between the exterior of the piston and the interior of the body to account for the (partial/exposed) width of the o-ring - if the gap is too narrow the o-ring will keep the piston from sliding easily. But this leads to a larger gap than necessary around most of the piston, and it feels as though the piston skews slightly when pressed. With this design change the larger gap would only have to run the small length of the body that the o-ring travels, and the gap could be tightened down for the rest. That's a nice enhancement, and while it does add one more part to the light, the change seems otherwise benign. Well done, indeed.
 

jimmy1970

Flashlight Enthusiast
Joined
Sep 6, 2008
Messages
1,044
Location
Brisbane, Australia
I don't think Selfbuilt is going to polish a turd just because he has the lights provided by the dealers. These reviews must be a right pain to do. They would take forever. I know I couldn't be bothered...

What I can't work out is why the D20 is so long?? The D10 is a nice size, if they made the D20 just 1 AA longer in length than the D10, I would buy one. By the look of those photos, the D20 is longer than my L2DQ5 with a clicky.

jr/
 

Burgess

Flashaholic
Joined
Apr 10, 2006
Messages
6,425
Location
USA
to SelfBuilt --


Another fine review here !


Thank you for your time, effort, and dedication.


:goodjob::thanks::twothumbs

_
 

Closet_Flashaholic

Enlightened
Joined
Nov 24, 2006
Messages
299
Location
Between East and West Coasts..
Thank you for the review.

What I am having a difficult time with is the large difference in runtimes at Med-High for the D20 vs. the Fenix..... The fenix runs for 1 hour more and it's brighter!.... They are both using Q5's.....

I like the D20 it seems well built and its UI, but the diminished runtime is holding me back.. I will have to see..
 
Last edited:

phantom23

Flashlight Enthusiast
Joined
Nov 3, 2007
Messages
2,044
Fenix uses current regulator which is more efficient than PWM in D20.

Selfbuilt, which T25 you have (looking forward to graphs on lower modes)?
 

selfbuilt

Flashaholic
Joined
May 27, 2006
Messages
6,936
Location
Canada
Thanks for the support everyone! :grouphug:

The D20 is the classy indoor performer of the group. Definitely worth showing off to friends and enjoying around the house on a regular basis.
Yup, the beam actually reminds me more of an SSC pattern than a Cree, thanks to that new reflector.

My only complaint is that I think it ramps up too quickly at the very beginning. It ramps down much slower than it ramps up. Or at least that's what my eyes are telling me.
No argument here - my ramping graph shows exactly that for the low-to-high ramp. I also find it moves through the low levels too quickly - but, technically speaking, it is actually more visually linear than the old ramp.

What I can't work out is why the D20 is so long?? The D10 is a nice size, if they made the D20 just 1 AA longer in length than the D10, I would buy one.
Yeah, that's why I pointed it out in my review. I too would probably prefer a slim-lined 2AA D10-type light.

What I am having a difficult time with is the large difference in runtimes at Med-High for the D20 vs. the Fenix..... The fenix runs for 1 hour more and it's brighter!.
As mentioned by phantom23, Fenix's current-controlled circuit (with its limited number of outputs and lack of true low) will always be more efficient at medium settings. Note also that my Fenix LD20 seems considerable less efficient on maxium than my L2D ... not sure why, and haven't had time to do the medium and low modes on the LD20 yet. Stay tuned ...

Selfbuilt, which T25 you have (looking forward to graphs on lower modes)?
It's the regular version. Haven't had a chance to do runtimes yet, it's in the queue. ;)
 

selfbuilt

Flashaholic
Joined
May 27, 2006
Messages
6,936
Location
Canada
Just updated the review with some detailed pics of the light engine

D20-10.jpg

D20-11.jpg


Note that I'm not able to adjust the focus of the reflector - it all fits together pretty securely (i.e. the reflector stops when it hits the brass pil).
 

Imothep

Newly Enlightened
Joined
Nov 11, 2007
Messages
30
The reflector design is interesting – this is one of smoothest Cree beam profiles I’ve seen. But unlike shallow reflectors (which smooth out rings but produce a wide and dim spillbeam), this deep reflector produces a more even (but narrow) spill output.

I can't agree with that in my case, my D20 is quite ringy compared to my old Fenix L2D Q5.

D20:

nitecorevsfenix1.jpg


L2D Q5:

nitecorevsfenix2.jpg


Overall I'm a little bit disappointed, it's not as bright as my L2D, throw didn't improve, beam is quite yellow compared to the slightly purple fenix, and it's quite big and heavy.

Anybody in Vienna/Austria who wants to have it?
 

phantom23

Flashlight Enthusiast
Joined
Nov 3, 2007
Messages
2,044
Many people like warmer tint.

About the beam - I've got three NDI's and each of them has different beam. One was very ringy, second one was perfectly smooth and third one was somewhere between them.
 

selfbuilt

Flashaholic
Joined
May 27, 2006
Messages
6,936
Location
Canada
Overall I'm a little bit disappointed, it's not as bright as my L2D, throw didn't improve, beam is quite yellow compared to the slightly purple fenix, and it's quite big and heavy.
I hear you - beam tint is variable, but mine is certainly a premium white. My results also show that output and throw is slightly less than the Fenix, and the D20 is definitely heavier.

But as for the beams, I think the reason mine seems less ringy is that the emitter is actually slightly de-focussed on mine (i.e. a bit of a donut is visible at really up-close distances). But I'm unable to adjust it since the reflector meets up perfectly with the brass pill - I would need to desolder the mini-star and shim it underneath if I wanted to get the emitter higher into the reflector.

Note as well that mine is even less ringy in real life than the beamshots look (JPEG compression tends to enhance ringiness) - my L2D has a pronounced dark ring in comparison in actual use. My D20 really does seem more SSC-like to be than Cree-like overall. :shrug:
 

I came to the light...

Flashlight Enthusiast
Joined
Nov 4, 2007
Messages
1,059
Thanks for the review :).

My first high-end flashlight purchase was a L2D Q5. I'm amazed that it is still on top, and by such a large margin! Although the fact that its "upgrade" doesn't perform as well is alarming...
 

Jarl

Flashlight Enthusiast
Joined
Jan 11, 2007
Messages
1,745
Location
Southern UK
Thanks for the review :).

My first high-end flashlight purchase was a L2D Q5. I'm amazed that it is still on top, and by such a large margin! Although the fact that its "upgrade" doesn't perform as well is alarming...

Agree with everything in that post. It's probably not a bad idea to pick up another couple of L2D's; I mean, they don't excel in anything really, they're not the smallest, not the brightest, not the toughest. However, when the sh*t hits the fan I can't think of any light I'd rather be holding.....

Looks like I better grab one for a BOB ;)
 

Axion

Enlightened
Joined
Sep 10, 2008
Messages
253
Excellent review as usual.

My L2D Q5 has the heavy OP reflector and as a result a VERY smooth beam, the smoothest of any of my lights by far, but it does tend to be lacking in throw. I was hoping with it's larger reflector the D20 would be better then the L2D in that respect.
 

Latest posts

Top