New Fenix LD15, not impressive

Received a Fenix LD15 yesterday.



Nice light, but:
LD15: 117 lm 1,80A 1,2V-----> 54 lm/watt (with a new AA Eneloop)
LD01: 85 lm 0,78A 1,2V------> 91 lm/watt (with a new AAA Eneloop)

Can someone confirm this?

light-reviews.com reviewed the LD15 (link). Their measurement of the high was 100 lumens.

mefistofele86 reviewed the LD15 (link) and posted outdoor beamshots comparing the LD15 and the LD01.

1 and a half hours at 100 lumens doesnt seem bad on a single AA cell. Are you sure your measurements were accurate?

Of course all single AA lights will very soon be blown out of the water by the new zebralight sc51 :devil:

I don't get it. You start a thread with the words, "not impressive" attached to a light model and then you ask a question that should of been asked by you prior your purchase.

How did the LD15 perform for you, how was the beam, what did you like or dislike about the UI, how's the texture..etc, etc. If you would post some definitive descriptions of your experience with the LD15 and then you were not impressed; that would be more supportive of the thread header. Your asking an OK question, but regardless of the answer, your negative header is not warranted in my opinion.

I'm thinking of buying this light and have an LD01 in my pocket as I write, so I am interested in information relating to the LD15. But when I read your header I said, "wow, may not be buying this one" and then I opened it and there is nothing of substance to support the negativity projected by your thread header.

Not coming down, just trying to make the forum a little better for everyone.

Double check your tailcap current measurements. Those Lumen output numbers look about right too. I would expect the LD01 to be in the 80-90 lumen ballpark, since it goes toe to toe with the ITP-A3... which has been measured at ~80L.

My Fenix MC-10 with an eneloop draws 3A (!!!) on HI, while only emitting around 115L (as measured by bigchelis). Thats only 32 Lumens per watt... not too far ahead of my most efficient incan.

The Malkoff M60 is around 45 Lumens / watt. IIRC

The harder the LED is driven the less efficient it is. If driven too hard, (beyond the thermal cooling design of the light body) then its lumen output will also diminish very rapidly.

A slightly under-driven Cree emitter in a hand sized host will almost always be more efficient (lumens per watt) than a hard driven emitter in the same sized light. Your numbers don't surprise me at all.

I agree with Kramer that those numbers are crap. If you were comparing to something with the exact same output (or reasonably close to it) that would help. I also doubt the 1.8 Amps measurement as that would crank out a lot more than just 117 lumens.

But yeah, obviously driving a light at lower levels is going to be more efficient than driving the same emitter at higher current for both reasons listed. First, emitters have a non-linear curve that gives less light/watt as you crank up the amperage. Plus the heat affects the emitter.

@BRO

I owned an LD15 for a week before selling it to another member on the MP who messaged that he's very happy with it. My impressions:

Good
- the beam is a very crisp cool-white and very bright on high
- the brass threads make twisting very smooth and the brass ring (which is exposed all the time) looks very elegant
- the light is VERY narrow for a AA and not too heavy with a battery in it

Bad
- high->low UI order
- for *me* it was a bit too large for keychain carry but it'd be fantastic for bottom-of-pocket carry
- it has the capacity to be a battery-crusher due to it's lack of springs, which is fine if you're the sole user but I was worried about loaning it out and having someone tighten it too hard

For what it costs it's a great light. For me personally it falls a little too between keychain/pocket while not being great at either, so without a place for it on my person I sold it off.

calipsoii said:

@BRO

I owned an LD15 for a week before selling it to another member on the MP who messaged that he's very happy with it. My impressions:

Good
- the beam is a very crisp cool-white and very bright on high
- the brass threads make twisting very smooth and the brass ring (which is exposed all the time) looks very elegant
- the light is VERY narrow for a AA and not too heavy with a battery in it

Bad
- high->low UI order
- for *me* it was a bit too large for keychain carry but it'd be fantastic for bottom-of-pocket carry
- it has the capacity to be a battery-crusher due to it's lack of springs, which is fine if you're the sole user but I was worried about loaning it out and having someone tighten it too hard

For what it costs it's a great light. For me personally it falls a little too between keychain/pocket while not being great at either, so without a place for it on my person I sold it off.

Click to expand...

Great feedback, thanks...BRO