List of (estimated) OTF lumen readings for quite a lot of common lights.

I got a luxmeter today, so put together this list of lumen OTF reading for reference. All are done with the lense of each light and the lux-meter at the same height/position pointed at the same angle towards a white ceiling. Once I'd worked out the multiplier (12 exactly) based on my LD20 which has very accurately measured med/high modes I went through a number of my other lights for comparisons.

All P60 drop-ins are wrapped very tightly in copper tape and my custom ones, including the nailbender xp-g which I modded down from 1.4 to 1.0amp, are thermally potted also for best heat dissipation, ultra-clear lenses are also used on my P60 hosts.

Stable refers to the the output not having dropped more than .1 on the lux scale (1.2 lumens) in the last 3-4 seconds, and does not necessarily mean the light will stay flat at that output over a minute or more. In fact this is certainly not the case on some modules e.g. the ultrafire 3 mode as it runs unregulated, which is why I have included cell voltage prior to measurement for these lights.

I was particularly impressed with my TK20 (my first decent light) and my modded nailbender R3 neutral XP-G, both of which I had subjectively thought were overperforming for some time, it was nice to have that objectively confirmed.

Re: List of (estimated) OTF lumen readings for quite a few common lights.

i thought the zebralight h51 was 200 otf..

Re: List of (estimated) OTF lumen readings for quite a few common lights.

You do realise that since your room isn't a properly calibrated integrating sphere you do have to use a regression formula that links integrating sphere readings to your ceiling bounce readings? The ceiling bounce isnt as linear as a sphere as the beam profiles can contribute to different readings (its more exponential as Selfbuilt pointed out). Oh well, its just an estimation.

Re: List of (estimated) OTF lumen readings for quite a few common lights.

Yes, I had expected the conversion not to be linear too for some reason. But the result worked so well on a linear scale with other people's measurements of high output lights that I left it. Now I think about it I don't see why the conversion of the objective measurement of lux to lumens should require anything but a linear conversion, I was under the impression that both were linear scales, while our perception and the variations of lux measurements across distance were logarithmic. I would be happy to hear any other input on this though, I could easily have forgotten/misunderstood something.

The test may also be slightly biased against lights with very wide angle spill beams, e.g. H501/H51/M3x/N30 HID, but I don't think the effect would be too great. I was very careful to test every light from exactly the same position etc, but when raising one up or down to avoid any of the beam touching the white wall instead of the ceiling I didn't notice any real difference in lux reading.

Anyway, I really wasn't surprised at the H51 reading, I had always maintained that my sample seemed no more than 150 lumens max and I thought 200 was an exaggeration. Of course that could just be my one and not representative of the run overall, although my SC51w seemed in line output wise also before it was lost in the returns process..

EDIT: Please note that ergotelis estimated lumen ratings also place the H51 output at 155 lumens on H1, I think this is accurate.

Re: List of (estimated) OTF lumen readings for quite a few common lights.

Just added my DX 4.2v P60 Xenon module, this runs at around 2A flat current on an 18650.

Also added results for my BC40 which I received today, it looked awesome output and having measured I am very impressed. Incredible deal from d*nodirect even if it did take a while to get here..

Re: List of (estimated) OTF lumen readings for quite a few common lights.

Added results for the Klarus P2a, Fenix LD01 R4 and Fenix E01.

They all seem closely in line with manufacturer measured OTF values, (bear in mind the E01 had the wire-wool diffuser technique done to it).

Also notice how similar the P2a and Jetbeam BA20 values are; the BA20 was measured with slightly fresher charged eneloops which increased low mode output a little but not high, so I would safely say these are using exactly the same circuit/emitter/reflector set-ups.

Re: List of (estimated) OTF lumen readings for quite a few common lights.

Now added results for my newly repaired D10 with 90+ CRI XP-G Q2 and D11.2 circuit, D11.2 with neutral white XP-G R5 and EX10 with neutral white XP-G R5 and EX11.2 circuit after receiving the new drivers + parts from the always helpful Nitecore CS team and a very successful repair session this morning

I've also added results for my new Olight S65 which I am very impressed with and also received this morning. With diffuser it gives an incredibly smooth and wide beam and the tint leans towards neutral Without it it's just an incredible AA powerhouse!

Further use of this technique for estimating lumens has convinced me that the linear conversion is almost certainly accurate, but that overall readings can be slightly lowered for lights with a very wide spillbeam such as the M3x, H51 and H501w, Quark Mini AA, Skyray 3x T6 and especially the N30 HID. Otherwise everything seems in order.

Added OTF results for the DRY triple XM-L T6 on a couple of different battery configurations.

Interestingly it seems to perform best with the Trustfire 2400 cells which provide a little less current and so I assume don't overload it with heat so much.

My favourite set-up is two unprotected and one protected cell. I'm hoping that this single cell's circuit should trip if they are overdischarging or shorting and therefore break the circuit. Hopefully I won't get any issues due to a difference in resistance between the protected and non-protected cells though..