People were expecting that it would work with blue excited LEDs. I guess that covers nearly all flashlights as well as most bulbs. The LM3 was quite good at them, it was even ok with incandescent bulbs. If the LM4 software can be developed to be on par, this would already be a huge improvement.
The graph is on page 11 of this datasheet:
Here’s another relevant datasheet of a high CCT, low CRI LED:
1 Thank
Reading your posts I stopped understanding what exactly LM3, LM4 was created for. This is a measuring device! What difference does it make where the LED is installed (if the device is only for LEDs), in a flashlight, spotlight, luminaire? Of course, the secondary optics makes changes in the light, but no one prevents you from removing it and comparing the light with and without it. Why, in principle, integrate the LM software with something else?
But still, should not a measuring tool be accurate over its entire range of measurement? I mean, visible light is visible light, regardless of its source.
I appreciate your participation, BTW. But I don’t understand the concept of selling a tool that only works under specific conditions… Unless those conditions are specified in the literature. If Opple had stated it would only be accurate in limited conditions, and it was, no one could complain when using it outside of those conditions. If it didn’t include the emitters that we use, probably no one around here would have bought it.
LM3 indeed supports incandescent bulbs, current supervisor here said there are less incandescent bulbs on market now, so incandescent supporting was dumped.
my personal belief is that we should develop a product that’s at least better than predecessor(in terms of features and precision), and release it when it’s bug-free. but you know, the release date was pre-fixed and I am just an engineer.
3 Thanks
I told the PM to print “Led only” on the packages of LM4(at that time, I only knew and tested home lights, mostly opple products including desk lamps and ceiling lamps et al.). yes, measuring device should not pick light, but the chip we use determine that we must calibrate or develop algorithm for each light source, not like integrating sphere. integrating sphere can read the full spectrum data of all VIS lights, of course we can calculate all metrics accurately using formulas(although some formulas are complicated for me, but I can overcome this).
actually I haven’t heard of any company around me that uses as7341 for ra/cs calculation, they only use it for CCT et al, CCT calculation may not require spectrum data.
My video shows that your LM3 algorithms are limping on both feet.
I guess because we are a lighting company, we manufacture lights, we are trying to become an IoT company by inserting bluetooth and wifi and other connectivity means to lighting device, we develop apps and so on. a lighting solution provider company needs a handy device to evaluate its own lights. that’s becoming closed cycle/loop.
we are in discussion with a domestic chip/module provider, but its module costs around 1000 RMB(about 136.6 US dollars), but I personally think developing such a device would contradict with our original intention.
can you elaborate?
I’m about my video on the effects of IR light sources. How else can I show you the problems of this device in more detail?
In my opinion, making a device that measures only its own LED lamps is something surreal )))) Explain my opinion?
Explain to me, please, who is a potential LM_ buyer. Maybe I really don’t understand something well.
Interior designers might want to use the LM3 to verify the installation of a dozen different Opple lights in a living room.
They can check to see if there’s an unreasonable amount of flickering that could annoy the customer.
The CRI and CCT can be verified.
Sometimes mistakes happen and the wrong light could be installed. The LM3 can help verify this.
An existing installation of old lights could be checked. The customer might want new lights with the same CCT but can’t remember what was originally installed.
I’m just guessing. 
That’s pretty much what I mean. LM_ needs designers, installers and … But these people usually work with different manufacturers. Why would they need any other devices in their LM_ software? OPPLE is afraid that their luminaires will not meet the stated characteristics? I could go on listing the nuances of my misunderstanding of the situation, but it would be a lot of letters. )))
Its a sad reality that most manufacturers of test equipment like this don’t open up the protocols. I asked Reed for their protocol on a meter and they didn’t want to give it out. And if you have an interesting problem of measuring with several devices at a time, data acquisition (DA) can be highly specific to your setup. Hard to accommodate unless you just give the users access to the protocols so they can roll their own DA.
Makes no sense to me, because it can only make the device more useful. The only thing I can think of, is they want you to use their app which is a sales funnel trying to up-sell stuff.
Problem is, there’s a very limited number of samples taken from the spectrum with those kind of sensors. They will miss important features, and hence the spectrum needs to be constructed by better interpolation methods than just linear, cubic, spline or similar. For this, you need a priori knowledge about the light source. Basically, you fit a function that represents a typical spectrum.
I personally wouldn’t mint adjusting the light source manually, i.e. chose blue LED, UV LED, incandescent and so on from a menu.
Anyway, it seems Opple is not even close to reproduce what the LM3 could do, let alone being better. I was told some months ago by Opple Europe that the LM4 would be late, maybe arrive at the end of this year. I now think Opple will need much more time than this.
Thanks for the explanation!
This sounds like an excellent solution. Select light source from a menu.
But they are talking about measuring their LED lights. Why is this different than LED flashlights? I would think that if the device is inaccurate with flashlight LEDs, it would be similarly inaccurate with any LED source. Yes?
different lights do show quite different characteristics.
all I said is from my perspective, I really regret that I didn’t major in optics/lighting related field. as a CS major graduate always trying to explain to you guys who are professionals in lighting industry makes me feel weird.
colleagues who are optics/lighting major should come here to explain to you guys, but…
1 Thank
In my opinion, your company is incorrectly positioning this product on the market. Hence the other questions. That’s my guess.
I can’t get what you mean by saying IR yesterday. the device is used for measuring VIS, not IR.
plus, I remember you mentioned IR long ago.