Kudos to Fenix on the L0D Q4 holiday special edition light

Luminescent said:

With normal batteries the original L0D-CE with a standard P4 was rated at 50 lumens on high, where the new L0D-Q4 is rated at 75 (one and half times higher output :thumbsup.

Aside from this natural increase due to the Q4's improved output, there is another factor at work with 10440 cells that needs to be taken into account. As I mentioned in a previous post in this thread, the Vf of the emitters is always a crapshoot, and and has been getting lower. If you got a lower Vf emitter in your new Q4 it will draw more current on 10440's which could also account for some additional brightness. You can easily check for this higher current situation by seeing which light gets hottest the fastest. The light that gets hotter faster, is drawing more current.

You can eliminate this variable quite easily. The L0D has very good current regulation when used with the batteries it was designed for, so to eliminate this Vf based difference, run both lights on identical NiMH cells or fresh alkaline batteries.

This should restore a precise 50% increase in brightness, which should be noticeable but not super super dramatic. If after the change to standard batteries, your new Q4 light is REALLY BRIGHT compared to your older light, then you may well have partially cooked the emitter. To be sure, you can check with a light meter because a 50% increase in brightness is less than one EV unit (one f-stop), so if you are seeing close to a full EV or 1 f-stop (or more) difference then that's a sure indication that you have lost some output on your older light.

You may have seen the recent thread from someone that had a couple lights in a row get dim after running them several months on RCR123's. Obviously since they were running RCR123s, these lights weren't L0D's but RCR123s were pushing this guys lights harder, just like 10440s do in the L0D (in fact the 10440 hits the L0D a lot worse).

So I don't think there is any doubt that long term, the 10440 can indeed nuke your lumens on a L0D (depending on how hot it gets and how many hours it is run), but some folks figure it's worth the price for the extra output.

In any case, I would definitely do the heat comparison check I mentioned and make sure your new L0D-Q4 is not getting too-hot too-fast, because if it is, that's a sure sigh that you are probably in danger of cooking the Q4 emitter (and are also at a higher risk of an outright failure due to high current popping something else in the light's circuitry).

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Ok luminesent, I tried this. I put a fresh NiMH, in each the LODCE and in the LODQ4. The Q4 in all modes was slightly brighter, not by alot ,but noticeable. I also had the chance to check my well used LODce against another with only a few hrs on it. Results the same, my well used(10440's) LOD is still putting out virtually the same lumins(visually) as a new one. So in my case anyway I can easily say that with 100+ 10440 battery cycles run thru the LODce, the light is no worse for the wear.:twothumbs

As far as heating up, the Q4 seems to warm up slightly faster than my older LOD, however again I don't think its enough to scare me off of using the 10440's in the Q4, the performance upgrade(with 10440's) IS huge. On the other hand running NiMA in the Q4 is close enough in performance to the old LOD running on 10440's that I may just continue with the NiMA . Personally I like the Q4 beam better than my old LOD, it definatly has a bit more throw, but still retains the impressive flood qualitys of the older light, and the tint is nicer in my eyes as well. All in all the red Q4 is an improvement over the older version, making an incredible little EDC light even better.

In response to the strobe critics. There is NO down side that the LOD has a strobe feature. Very soon you get used to whipping it out of your pocket and giving it a quick one handed twist or 2, to get to your desired mode which 99% of the time is med or low. The strobe mode is the 4th twist, which does NOT get in the way of normal operation. However don't underestimate the advantage of strobe. You can easily get someones/anyones attention whether day or nite with a quick burst, try it even in daylight you'll be amazed at its effectiveness. Not to mention the obvious safety factor of getting attention in case of emergency.

A few LOD tips

how to.... put the clip on without scratching, use a bit-O-spit, it will slide on easier, no scratches.
how to.... make the LOD bite friendly and one hand friendlier, put a single wrap of tommy tape(self fusing silicone) around the head and tail end.
LOD xray ....on high using 10440's close your hand completly over the LOD in a dark room.

todo said:

Ok luminesent, I tried this. I put a fresh NiMH, in each the LODCE and in the LODQ4. The Q4 in all modes was slightly brighter, not by alot ,but noticeable. . .

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It's great news that the emitter in your old light isn't cooked. It sounds like my guess was correct, the lower Vf is making your new Q4 draw a bit more current, and this PLUS the better efficiency that the Q4 has to start with, is accounting for the dramatic difference you are seeing, because there are two factors at work not one.

I can understand your mixed feelings, on the one hand it's hard to resist the incredible brightness offered by the L0D-Q4 on 10440's, and on the other hand it sounds like you got a near perfect L0D-Q4, so it would be a shame if it died on 10440's (which does happen), because it's replacement may not be quite as perfect. There was a quick survey where only about 10% of the users of 10440 cells reported problems, but with the newer lower Vf lights, I would not be surprised if that number will rise in the future to as high as 1 in 3, so it's up to you if you want to roll the dice with those odds.

For me at least, the deciding factor, aside from reliability, is runtime, which will be painfully short in all modes on your Q4 when running 10440's (due to the same higher current draw that makes it so spectacularly bright).

In my last post I recounted how having a backup light (that I barely remembered was in the car), saved my skin one cold drizzly night while changing a tire on a dark lonely stretch of road. Having a backup light probably saved my life that night, and that's one of the things that lead me to try to be a little more diligent about having a good reliable EDC light with me at all times.

Don't get me wrong, I am ecstatic about the fact that the L0D can run on 10440's and work fairly reliably, but NOT because I plan to use them in my L0D-Q4, but because the fact that this little light can survive this kind of abuse and still rack up a fairly reasonable record of reliability, tells me that if I stick to Alkaline, NiMH or L92 cells, my L0D-Q4 will never never never let me down, and the next time my life depends on having a flashlight that works, I can depend on my L0D.

As far as the output goes, even on NiMH batteries, the tiny little L0D has roughly three times the outputof the early 1 Watt Luxeon III light that saved my butt that dark cold drizzly night, so how much brighter does it have to be???

So even for someone like me who doesn't plan to run 10440's, the fact that the L0D can survive being blasted with more than 5 times it's designed level of drive with these cells is impressive, and serves as a usefull indication of just how tough this little light really is.

You guys convinced me, I pulled the trigger on one of these things yesterday evening. No 10440s for me, I'll just be using my Eneloops, but still I think I'll be pleased. These AAA and AA lights are where the most pronounced manifestation of new LEDs are going to appear... eventually we'll get away from the "more light at the same current" to "we already have enough light on medium and low, just keep dropping the current as emitters get better."

Can't wait to get mine! (My first Fenix! )

Which is the best LOD model? Fenix offers a number of them, and only lists the rebel on their website.
Better includes reliability as well as brightness.
I won't rule out a red model, since other aspects of a light are more important - e.g. finish durability, light reliability, beam, etc.

I find the kudos interesting but being the flashaholic that I am, it must be quantified in person...with other flashlights of course! :thumbsup:

I have a KD SSC-U AAA light that uses a Seoul LED with a runtime of a bit over 20 minutes. A Peak Baltic AAA with the highest output is on the way for comparison. The brightest go head to head to see who wins.

My initial belief is the KD SSC-U AAA light will win since runtime be damned, it is all about brightness. The Fenix L0D Q4 wins for the keychain as it is tough enough to withstand that duty but not "bomb-proof". The Peak Baltic AAA with SSC LED running at max output (maybe an hour?) it is the dark horse. It's job will be the tool of the group and will reside in the small side pocket of a Leatherman Charge Ti leather holster.

The KD outblasts the Fenix Q4 and the Q4 should be close to the Peak Baltic. Maybe this week I'll find out how this all plays out. If the Baltic replaces the KD as my tool holster light, what will I do with the KD? Oh yeah, ship it to my brother with a Powerex 1000mAH NiMH for Christmas.

Who would of thought that a single AAA NiMH light would be good enough for most uses a year or two ago? I don't need "cheater" 10440 cells...life is good!

arty said:

Which is the best LOD model? Fenix offers a number of them, and only lists the rebel on their website.
Better includes reliability as well as brightness.
I won't rule out a red model, since other aspects of a light are more important - e.g. finish durability, light reliability, beam, etc.

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There may be some other very nice L0D options later, but for now Fenix seems to have whipped up a big batch of these red L0D-Q4 lights for the holidays, and they are the highest performing L0D lights currently available (75 lumens on high).

If you don't mind the red color then the light you are looking for is:

Red L0D-Q4 seasonal special at the Fenix-Store

Fenix store helps support this forum, and unlike most other U.S. Fenix dealers, their price includes free shipping and they offer CPF members an 8% discount (use the discount code CPF8 since you are a member here). I'm not knocking any other Fenix dealer, but this is a great price and you can't go wrong dealing with the Fenix-Store folks as they have a very good track record here on CPF.

Remember the silver P1? I'd like to see them bring this color back as an alternative to natural. Oven olive drab (P3D limited run) would be something different to try.

LOD-Q4 vs. 100W incandescent shop light -

There has been a sub-thread in this thread relating to the brightness of the L0D-Q4.

Is it bright enough on NiMH?

What about a this other Brand-X light that can do 100 lumens but has only 20 minutes run time, wouldn't that be better?

For me the most important advantage of the higher efficiency Q4 emitter is that it gives the L0D a very nice combination of very respectable output AND good runtimes, making this little AAA light a very nice replacement for a larger light in most applications.

In a previous post I compared the L0D to a 100W shop light. Most of you probably thought that I was just speaking metaphorically.

I was not, I was speaking literally.

So, for the benefit of those who wonder if 75 lumens is really 'bright enough' for their EDC light, lets look at that 'L0D vs. 100W shop light' comparison in a little more detail . . .

The hot spot on my L0D is about 1 foot in diameter at about 4 feet (this may sound small but, it's actually a little on the floody side, and the hotspot has soft edges that make the L0D very pleasant to use close up).

So now let's compare that hotspot brightness to the brightness of a 100W shoplight at the same working distance.

The 'shoplight' I am talking about is one of those simple bulb fixtures with half the bulb covered with a simple reflector.

Let's use a big bright 100W bulb in the shoplight.

First the L0D . . .

Based on the efficiency of the average flashlight reflector, the L0D should be putting at least 25 lumens of it's 75 emitter lumens into that hotspot (a little is lost and the rest goes into spill) This is a fairly conservative estimate. Using the PI*R^2 formula a 1 foot circular hotspot has an area of about 0.78 square feet, so the luminous intensity of the hotspot of the L0D at a working distance of 4 feet would be something on the order of 32 lumens/Square Foot.

Ok now, now lets figure out how many lumens / sq ft. a 100 watt shoplight throws at the same 4 foot distance . . .

GE specs their 100 watt longlife incandescent bulb at 1600 lumens while a 750 hour crystal clear bulb can do a little more at 1750 lumens. Let's be as fair as possible to that good ol incandescent bulb and use the higher figure.

1750 lumens, that's huge! The little L0D doesn't have a chance right?

Wait, we are talking luminous intensity at 4 feet in lumens / square foot, so let's do the math –

The 1750 figure is the TOTAL light output of the 100 watt bulb measured using an integrating sphere, so to figure out the lumens per square foot at four feet, we need to figure out the surface area of a sphere that has the same radius as the 4 foot working distance that I used above to calculate the 32 Lumen/Square Foot figure for the L0D.

The surface area of a sphere is calculated as 4*PI*R^2.

So a 4 foot radius sphere has a surface area of . . .

4 * 3.14159 * (4*4) = 201 square feet.

So with no reflector the filament would spread it's 1750 lumens evenly across 201 square feet at four feet.

Let's be really really generous and assume that the little crappy shoplight's reflector is 100% efficient and that it perfectly reflects half the lumens back across to the other side so that the 1750 lumens is only spread out over a half sphere at 4 feet.

This would give us 1750 lumens spread out over roughly 100 square feet.

Gee, that's an easy calculation; dividing our 1750 total lumens by the 100 square feet that they spread out over at 4 feet, we get 17.5 lumens / sq foot.

That's just a little over half the luminous intensity of the hot spot thrown by the L0D-Q4, and in real life the 100W shop light would probably be less than half as bright, because for the above calculation I made pretty pessimistic assumptions for the L0D and very optimistic assumptions for the 100W shoplight.

Of course the huge cheat I am using here is to compare just the 'hot spot' of the L0D, to a shoplight that is almost 100% flood (though, remember, I did throw in a 2:1 reflector factor and use the highest output 100W bulb commercially available to favor the shoplight).

Actually, I don't think this is unreasonable at all, because the L0D has a nice moderately floody beam, and because of this, it's not too hard at all to keep what you are working with centered in the beam and fully illuminated by that nice floody hotspot.

For example, if you are reading a paperback book, and you hold the L0D at a distance of only 3 feet you can cover the whole book (both pages), with this equivalent of '150 Watt shoplight' bright illumination.

So, I apologize, I miss-spoke before, if you light something up with the L0D-Q4 it isn't 'just as bright' as a 100W shop light, IT'S ALMOST TWICE AS BRIGHT at any given distance (and the inverse square law works the same for both the L0D and the 100W bulb so this will remain true at any working distance, not just the 4 foot distance used above).

Not too bad for a light that runs on a single AAA battery (and remember, all of the above calculations are for an L0D-Q4 running on HIGH on a standard AAA NiMH cell, not a 10440).

Thought you would get a kick out of this. :thumbsup:

Wow, this is a great light! Wish the all-night market had some lithium aaa's per cpf'er luminescents post. This is my first fenix and I am honestly impressed how bright this light is, especially for its size. It is going to be a bright year if the led manufacturers can continue to supply the flashlight market with ever efficient and well tinted bins. (good driver design helps too) :thumbsup:

This light is so tempting, but I have to wait as I just purchased a Fenix L2d-CE Q5. Maybe I will wait until they release a Black Q5 version?

I have had my L0D Q4 for several days now and I have wowed many people and I still have the wow that is bright giggles myself. This light is not my brightest but it is by far my favorite.

After reading all the posts in this thread (especially Luminescent's insightful posts :bow, the posts in 4sevens Holiday Speacils thread, and some other threads - I bought one last night, even though I have a L0D CE that I like a lot.

I even bought some 10440 batts and charger to run in the L0D CE, but decided against using 10440's except to wow folks from time to time. The L0D Q4 should have plenty of wow factor as well as being a very good EDC light coupled with use as an emergency light in the unlikely event of an emergency that turns out to be more likely than not .

Cheers:thumbsup:

Thanks to Luminesent for an excellent thread, highlighting this very usefull little light.

Here is a picture of my 10 month old everyday carry LOD ce. It just won't quit, but if it does I have the even better Q4 waiting to take its place. Note the tommy tape on front of light makes it much easier to handle one handed, and the tape on back (with bite marks LOL) making it bite able.

Slick... I do something similar.

An Amazing little light! :twothumbs

Got it on Monday and can't stop playing with it...

It seems to have a bit more flood than my L0D CE as well as a more intense and whiter beam.

The tube is an reddish orange, it has really begun to grow on me. So much so that I have already gifted my CE to a friend... she loves it! :kiss:

The specification of this LOD Q4 is impressive. And I don't mind the red colour. Anyhow, from the fenix store web photos of this little light, it seems that there are the X'mas decorations "printed" alongside the fenix logos. The problem is that I couldn't see clearly how it looks on the logos and I couldn't tell really if I mind it. Any LOD Q4 owners post pictures on the logos of this little beauty please?

ymfymf

I thought the xmas logos would be a deal breaker (especially as I bought this for a gift), but they are really very small, and barely discernable to my eyesight.

Here's a pic that shows them clearly (but this is larger than life-size, obviously)

Thanks for the photo alfablue. I think I like the red colour honestly but I won't buy it because of the X'mas logo.

ymfymf

Really, they are really unnoticeable, just look like feint white blobs without a really close look. And if you use the included clip, that can be positioned to cover them. I first ordered the LOD CE because of the logos, but n hindsight they are a small price to pay for 75 lumens over 50 lumens.

Nobody I have shown the light to has noticed the Holiday icons. They are so small and when you hold the light they are covered up. To be honest I had forgotten about them until I saw these posts. On one hand I kind of like a note telling me how old the light is. That way months from now when I am trying to remember when I got this light, I will know. Anyway, the red/orange is nicely done and is much better in person I think. And the holiday symbols don't stand out as much as these pictures make it seem to.

This light rocks!