I received mine today… Just like TimMc, I had to sign up…
Keep in mind that when you try to login as a guest, it asks you to scan a QR code, which will then send you to the built-in browser to visit Google Store again… so it’s kind of useless.
It looks like you need to sign up…
btw, mine is called; Opple Smart Lighting… not Opple Smart
btw. this App also works with Opple Light Master 3 (pro)… It’s just not showing the R measurements, and DUV
I agree. As @Quadrupel already said and the different types of problems suggest, the chips are not calibrated. If it’s done in the chip itself or elsewhere in the box I don’t know, nor do I know if the Opple LM4 firmware can be updated in the first place.
Seems to me like a lost cause.
Got my LM4 today. These are the lights I can measure IF25A,TS11,S21D 10 Degree optics,M21F FC GT40 4000K-4500k,TS30S PRO.
How do I measure them? Lux,Distance Testing techniques?
Are people with LM3 using Light master pro software or Opple smart lighting?
If I measure the sun should I not get 5000k-6000k? Shouldn’t everyone get the same? As you can tell I’M new at this.
here is some Opple4 data with Lee Filters
clic pic to see source:
the good:
imo the data looks pretty consistent in terms of the change in DUV, and the CRI R9 seems pretty consistent
also note that maukka saw a duv drop of 0.0040 from using a 1/8 minus green… so imo, the duv measured on the LM4 is very much IN the ballpark…
clic pic to see source:
backstory… the Lee 804 has a light loss of 16%, the Lee 1/8 minus green has a loss of 13% making them roughly equivalent imo…
the bad:
it also confirms caanga’s observation that the spectrum plot does not change
Jon that’s a very interesting way to check. I’ll try it later.
My problem is not with the low CCT lights. They are different but not bad and did form a predictable trend (more positive). And CCT, Ra, and R9 look ok. No problem here.
The weird values: R9 of 100, Ra too low, CCT too high, are with high CCT light such as IF22a, Mateminco, and Wurkkos TS30S 1st gen. In these lights Duv is way too negative and negative for a very green LED. Do you have any high CCT lights?
That’s the basic problem, two opposite trends: too positive for low CCT lights and then too negative for high CCT lights.
This. Bluetooth handles checking integrity of the transmitted data. It either arrives or it doesn’t. If it was only inconsistently connecting/working at all that might point to a bluetooth issue.
Light Master Pro for me
I just received my LM4 and tested 3 lights, plus ambient:
First impressions, Opple 4 ambient CCT and DUV taken at very low Lux is unreliable
On the three lights the
DUV is 20 points lower on Opple3 than on Opple4 on two cool lights, and 30 points lower on the warm light,
CCT mostly close on both Opple 3 and Opple 4,
CRI Ra approximately similar on both Opple 3 and Opple 4,
CRI R9 seems to show relatively useful values for comparison purposes… for example, the XM-L2 has much lower R9 than the High CRI lights… although I think it is actually lower than measured. Normally Low CRI lights have Negative R9, considerably lower than the 18.7 the Opple 4 reports.
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here is a simpler data dump… from a single light w NW XM-L2:
first impression, the
R9 of 78.5 from Opple 4 is dead wrong it should be negative since this is a Low CRI LED…
here is an example of an XM-L2 that maukka measured at R9 -31:
Sad because I was hoping the R9 data would be useful. That was my main reason for buying it. My other reason was to get the precalculated DUV, but it is also wildly inaccurate with my CW TS10… so… foggedaboudit
Fully charge the battery for each flashlight.
Put the LM4 near the edge of a table or on a wall so that it doesn’t have light reflecting off other objects. This will impact the CCT and duv.
The room should be dark so that the LM4 doesn’t display any measurements when on.
Put the torch in a tripod or a stable surface. Point it at the LM4. The torch shouldn’t move.
Use a regulated mode (Medium?).
Start the LM4 app.
Turn the torch on.
Take a screenshot (capture mode on Android for full screen).
Turn the torch off.
Make a note of the distance, battery (if multi chemistry) and mode used (Medium).
Doesn’t it make sense to use whichever mode you will actually use the light in?
Don’t you also need an Integrating Sphere to properly measure CRI components?
Eg: The principle and basic calculation of CRI - LISUN
How are you guys measuring it? I think you are too quick to blame the meter.
That’s unfortunate that the R9 and DUV appear to be so inaccurate. Those features were also what I was wanting most, especially the R9 reading. Glad I resisted the urge to buy one.
On the hypothesis that the issue is with CW LEDs, I tested an sw45k:
the numbers seem less wildly different… the R9 of 80.3 is in the balpark for a 9080 LED… When maukka measured an sw45k he got R9 of 97, but it is not the same LED: His DUV value of -0.0055 is much different than the two Opples I tested… though again, not the same LED…
pic is a link to source:
It does seem like the Opple 4 might have more severe issues with cooler lights, and low cri lights…
hard to be sure unless someone does a side by side w a sekonic, for the same LED…
fwiw, here is a 519a 5700K:
I ordered another Light Master Pro 3 to do direct comparisons with the Light Master 4 while I’m 30km from the Opple factory in Suzhou. 
Have a great Trip!
So is there hope this is a firmware issue or is this a calibration issue that can’t be fixed?
Probably need more data. It’s looking like there are inconsistent results where calibration might not help, unless each device is calibrated. The same correction factors might not be applicable to different units if they’re all different.
The documentation describes different approaches to calibration. Without going into the details: Measuring a prototype and calculating the matrices from it for all chips doesn’t give good results for all possible measurements. The R-values might never be entirely ok.
