iPhone Light Meter App.

[1793]

Do any of you have any information about a light meter app. for an iPhone 5s.
I would like something for occasional residential lighting.

Thanks

 

[ron]

I have not done extensive comparison, but I use a product from Whitegoods called lightmeter

 

[MNWildcat]

Meh

Meh

I have reviewed a few free one that I found. Unfortunately none were very accurate compared to a real meter, but they do give some indication of light level.
I used the whtegoods one, but don't have it on my phone now, so it must have been relatively inaccurate.
I currently have Galactica Luxmeter and LuxMeter. Both units are lux in lieu of FC, but the conversion is easy (.1x).

 

[1793]

I have not done extensive comparison, but I use a product from Whitegoods called lightmeter

Thanks, I'll give it a look see.

 

[Electric-Light]

Thanks, I'll give it a look see.

It's easy to make a sensor for consistent light source like tungsten or sunlight, but properly compensated sensor that can properly weigh out LED, or a mixture of sources like LED & HPS is more challenging. I wouldn't accept an iPhone measurement particularly if it's used to validate project success or specification compliance involving LED installs.

Intensity of light energy is objectively measured in mW/m^2 and brightness is measured in lm/m^2

Given two light sources each emitting 100mW of energy onto a 1 m^2 surface, one green, and one deep red, the green will have a higher LUX or FC value as a result of weighing it to human eye response. Sensors don't perfectly match our eyes and some light meters are quite sloppy and show quite a bit of difference depending on light source even at the same FC level.

 

[electricalist]

My supervisor and I both tried a few and they were far enough that if you need 100 lumens in a elevator pit DONT trust it.

 

[Electric-Light]

My supervisor and I both tried a few and they were far enough that if you need 100 lumens in a elevator pit DONT trust it.

If the system is sub-standard and one of yours read in favor of the performance evaluation, which one do you think will magically find usage? To prevent someone from gaming the system, it's important to use a proper meter. LED's have a different spectral output than fluorescent lamps, so it's particularly important that you don't let the Energy Retrofit Sales service do the check-off on their own curriculum.

 

[electricalist]

Yes sir we weren't using it for real. We did actually fail a pit inspection but it was because the architect specified the wrong lights. We were seeing what the app version said on the failed ones then on the pass lights,,,him on his iPhone apps me on my android apps. Neither were even close.

 

[steve66]

I've tried different light meter apps on both my android phone, and on my Ipad.

None have worked. They all seem to read only specific values. When I held one under a light while I turned up a dimmer switch, it would read 0, then maybe jump to 28 FC, then to maybe 55, and then to 100. Then the same thing on the way back.

 

[1793]

It looks like I will be purchasing a "real" meter.

Thanks to all for your input.

 

[Michael15956]

Intensity of light energy is objectively measured in mW/m^2 and brightness is measured in lm/m^2

In lay terms, what is the difference between "intensity" and "brightness?"

 

[GoldDigger]

In lay terms, what is the difference between "intensity" and "brightness?"

One measures physical energy per unit area, the other multiplies the energy by the relative sensitivity of the eye to the frequencies of light involved.
No amount if far infrared, for example, will produce any brightness.

 

[Electric-Light]

In lay terms, what is the difference between "intensity" and "brightness?"

They're exactly the same concept.
Whether you apply a pound of force with your finger on the floor or you use a nail, the amount of force applied is exactly the same. You're increasing the INTENSITY of force, or pressure by using a nail.

Brightness adds in the human perception factor and it weighs in the "pitch" or the color.

100 dB at 4,000 Hz or at 20,000 Hz, it is still 100dB
The perception at 20,000 Hz is much weaker than it is at 4,000 Hz... but that doesn't mean 100dB @ 20,000 Hz won't cause a hearing damage.

 

[Michael15956]

Thanks guys!