Opple Light Master III (G3) discussion thread (Cheap device for measuring Lux, CCT + CRI)

is it possible to make runtime graphs for flashlight testing in this app?

No way to record or export data except taking screenshots.

I personally use a fairly inexpensive setup I created using an ESP8266, documented here

I also recently noticed that my luxmeter (UNI-T UT383BT) has logging capabilities and can export the data to a CSV file or PNG. The capture time is adustable: 0.5s, 1s, 2s, 5s, 30s, or 1m. I do not know how long of a capture it can take. The app is called iENV.

Received Opple Light Master Pro

did a quick test of a Tool AAA w sw35

CCT estimate seems very accurate:

Flicker index:


calculated DUV from X-Y coordinates:

I plugged in the Opple to recharge… it only had 1% battery left when it first arrived.

First thoughts
very tiny, pretty good CCT measurement… dont know what to think of the flicker index yet…

So far, Im happily entertained. The unit took 21 days from order date to in my mailbox in USA

I do not know if there is an R9 or DUV display, yet. But the spectrum chart shows Tint below BBL… seems good…

sw45k test:


Looks pretty good. It’s manual, but you can always plug your x,y values into this form to get Duv.

The 3500K: –0.0017
The 4500K: –0.0122


shaved LH351d 3500k:



data overload… LOL

Haha, nice. Mine just arrived in my state today, so hopefully I’ll receive it in the next few days.

Interesting that yours says PRO. The software looks the same. I even looked for older releases of the software, but couldn't find anything that looked like the pictures on Aliexpress.

I think Pro = G3

here is one of the selection screens in the app:

and here is a reading of the daylight on my desk, Im quite pleased that it seems to be CCT and CRI Ra accurate:

I do not understand the flicker info, yet… this is the same daylight:

The flicker seems to be measuring 2 things:

  • Frequency on the X axis. Eg Anduril lights have PWM normally at 16kHz, which isn’t noticeable to most people. The Opple is measuring up to 10kHz. You should be able to see this change on the Anduril party strobe mode.
  • Modulation depth on the Y axis. This is normally 100% on flashlights with PWM. That is fully off/on. The bike flasher mode on many lights switches between 50% and 100%

Combining these in the chart gives a “flicker index”. Low numbers seem to be good (green) and high ones bad (red).

You can see that a slow flicker is fine (still in the green area) as long as output barely drops. You can also see that completely turning off and on is fine above about 5kHz.

In the screenshots above it looks like the Opple is detecting slower fluctuations, rather than PWM used to dim the light. Do you have a light with terrible PWM to test?

Edit: I had assumed that this was something Opple made up but a “flicker index” looks to be a standard measurement. LEDBenchmark - Measuring Flicker

I dont own any old and slow PWM lights anymore

but here is an Eagletac D25A:

the Opple is the first instrument Ive found to help illustrate the constant current flicker of the ET…

here is one example of FWAA flicker data…

Dang it, really want mine to be here… has been sitting in Chicago since the 11th and USPS has not taken possession of it yet! Ordered on 9/23, made it to the States by the 11th and now it camps out. I swear USPS should go away… the grand fix is to slow down the mail and charge more to deliver it? Really does not make sense to me.

youre gonna like it, I hope you get it soon

Im really pleased
got my living room lighting to about 3100k, 95 CRI Ra, DUV –0.0021, and the flicker is in the “No Risk” zone… I feel better already… LOL


I just compared the Lux of my FWAA to my single sw30 in an RRT-01… it takes 50 lumens on the FWAA, to put the same LUX on target as 9 lumens on the single LED reflector hotspot…

talk about inefficiency of triples… floody beams burn lumens.

this little Opple is the funnest gizmo Ive bought all year

Hahaha, nice. Great to see such a quick convert :D

I think it's a pretty nice tool.

Mine has only just left China after ordering almost 3 weeks ago.

I think they were trying to work out how to ship it to the UK following Brexit.

Where did you order one from? I looked a few weeks ago and the shipping was killing it

a friend in UK was able to order from the link in post 16 that I used

Shipping to the EU and UK is extremely expensive. Almost the same price as the thing itself.

a friend in London used the link I provided and his total price was
GBP 24.54, with UK VAT paid.

I ordered from the same AliExpress link but the postage was about £20. It’s now listed as free postage but taking 6 weeks.