To be honest, I'm not a big fan of sharing DUV numbers either, since they depend on so many variables.
I added them to our reviews, because they were requested by a reader.
@ thefreeman: did you make that image yourself in post #314?
They don't seem to correspond with this part of the video: https://www.youtube.com/watch?v=isds2qNtF6Q&t=1525s
Great discussion by the way!
I find pairing the Opple data with a Photo of the actual beam, increases the usefulness of the DUV data:
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but I dont expect my DUV number to match your DUV number, even if you use an Opple, and I do too… because Your LEDs and Hosts will also vary.
Yup, very true!
Just received a reply from Opple, and they said they are planning on updating the app, and include the different R values...
FYI
Cool, thanks for sharing :+1:
No release date given I guess?
Correct.. no other info was provided.
April?
Yes, but just the announcement. On April 1st.
We showed that back on page 6— it has no response (no sensor) in that band.
ChibiM can you ask them, if they could add a feature to do runtime graphs with the opple? Or even export the data to a csv?
Thanks, I wonder where I got the idea that it might damage the sensor - I just assumed. With the sensor not even registering those wavelengths it should be safe.
Export to CSV would really be pro, the runtime graph would be a nice extra but somewhat unnecessary imho. I'd use it if they'll add it though heh!
Tested a Convoy S21D with quad 519A 4500K emitters - high quality lighting for cheap.
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S21D 519A 4500K 0.1% @ 2ft
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S21D 519A 4500K 100% @ 2ft
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Very very floody, it was hard aligning the sensor to the hotspot on this light since there is virtually none. Great light, smaller diameter head than an S12/S16, shorter too. They basically refined the S1* model for better EDC.
Do you think that is a typical accuracy of measurement for a 4500K emitter? (4312 and 4150)
congrats on your 519a light
similar CCT and DUV to one of my 519a Opple readings
and also similar cct to one azhu measured at 4300k (not w opple)
the lines indicate dedome change, on his samples…
Im carrying a dedomed 519a 4500k, it reads 3400K on my opple, Im quite fond of the light, and my Opple is very handy too
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great LEDs, red colors really Pop!
For this device, lack of a standardized procedure between users, not using an integrating sphere, and perhaps not the datasheet spec for delivered current….sure. Quad doesn’t help either, I guess. My recollection (correct me if I’m wrong) is that the bare emitter CCT is measured in a sphere, so you’re getting the whole range of spectral transmission…should be the same for an emitter with optics fitted although that will change it of course. Measuring just the hotspot usually reads lower than advertised temp for a given current, and of course there’s the shift in temp and/or tint with most emitters at lower current.
I did see that datasheet and graph back in the thread, btw…actually it was that graph that made me wonder if the UV might actually give some kind of CCT reading since it shows something not-quite-zero down there, but of course that’s a coarse graph, and the barely visible light that comes from the filtered 365nm I guess isn’t enough to register, either. Just thought it was interesting, had wondered about it when following along and trying to decide if I wanted to pick one of these up. Leaning strongly toward that Hopoocolor now…tax refund time is upon us!
Without testing the bare LED using a real spectrometer I can't really say, too many factors to consider - even the measuring device (Opple) can affect measurements. I'd say the results should be repeatable on my device, but I'm not gonna say the data that every Opple spits out is scientific truth.
Oh I love it, I'm just getting tired of all my 4500K lights lol! And I'm leaning towards trying a dedome - 3400K looks sweet.
I do like to include duv measurements with led tests because it provides relevant information for flashlight enthousiasts (I use a spectrometer), and because the duv is dependent on how you measure it (as Chibi mentions), I have standardised how I measure it: I place a small smooth reflector over the bare led and measure in the hotspot that the reflector produces, I usually provide duv results for a couple of different led currents. I chose this because that is how a led is often used by flashlight people, so it is a useful measurement. People who are used to modding flashlights with different leds will know that a TIR optic produces a hotspot that has a bit lower duv than a reflector, and they know the influence of a AR-coated lens on the duv, so the results can be somewhat extrapolated to various situations.
How I do not measure duv:
*straight above the bare led. That part of the light cone of a led has the lowest duv, that is far from representative of the total light output of the led. You may only get close to this light in an aspheric build (that predominantly uses the light straight above the led).
*in my integrated sphere, because that removes blue from the spectrum/lowers the CCT by at least 300K; if the sphere changes the spectrum I can not imagine that duv is not affected too. One exception: If you own an integrating sphere combined with a spectrometer, and the data is corrected for spectrum changes by the sphere, this wíll work fine for duv measurement of the total output, but by my knowledge maukka is the only flashlight hobbyist that owns such a setup.
Purple, green, blue? Which are going to raise or lower the duv? I’ll do some testing over the weekend.
Thank you Djozz for the explanation. That's really helpful.
