So, since my last two OTF lumen tables: (1 - List of (estimated) OTF lumen readings for quite a lot of common lights. and 2 - Comparative lumen readings) I not only have more lights to test, but have also changed my testing set-up. It seems that the placement of the lights and lux meter, which was an acknowledged issue for V1, was still causing an unecessarily significant bias in V2, dependent upon beam profile.
I have tried a few different positions and now feel that I have ‘fixed’ this bias for a more reliable set of readings. Having done that, I spent a good deal of yesterday testing almost all of the lights that I had to hand. The following table shows my results.
One thing to note is that, due to the repositioning of the lights relative to the lux meter, my lux readings and conversion factor (32) were much lower and higher respectively. This means less accuracy at lower readings, as the lowest possible increment was 3.2 lumens. In light of this I have had to omit a few lights lowest modes, and I would also advise caution in accepting any sub 10 lumen readings as particularly accurate (although they should still be accurate to within 1.5 either side).
Anyway, I hope you find them useful and/or interesting
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With regards to the small output difference on the H7 between throw and flood settings, I think that this is best explained by the fact that whilst the focusing of the light to throw is much more efficient with LED Lenser’s TIR system than a conventional aspheric, it still involves raising the TIR so that the cone surrounding the LED is slightly higher than optimal. Therefore in max throw mode the optics are still a bit less efficient than in full flood.
Yes, the Mini-X was with an AW RCR123, but not fully charged, probably around 3.9-4v. I’m always impressed by it’s output tbh
Yes it took a good few hours yesterday, but I like knowing where all of my lights stand output/efficiency wise.
Unfortunately my lux meter is a cheap version from DX and I believe severely underreads, and so is only really good for relative numbers. However my EA4w on max read 11.4k at 1 metre, with the D40A at 14.4k and Original Skyray King at 16k for comparison. As Kings generally read 20-24k at 1m I would up the others in proportion for more accurate values. I also think that the EA4 would benefit from a measurement further out and being extrapolated back, the beam doesn’t seem to be fully focused at only 1 metre.
oh ok, thanks though. looks like adding 50% to your numbers gets it into the ball park of actual lux though, from the numbers you gave compared to the skyrays typical, and my readings on the ea4w (if mine are even accurate)
Have you tried drastically closing the distances between the light, the bounce surface, and the meter surface?
FWIW, I use a DSLR to meter my lights and found much better accuracy and consistency, especially in the low and sub-lumen range, when I switched from a vertical ceiling bounce to a horizontal narrow-hallway bounce. Also matching beams sizes (spill diameters) between lights seems to equalize floody and throwy lights quite well too…
Thanks for that, it’s a good idea. I think I’ll leave it for a while though as I’ve only just done all of my lights using this method. Maybe for when I get around to V4
