A Light Meter For Your iPhone

We've discussed using smartphones to measure light in the past, so this caught my eye. Lumu, via Kickstarter, is claiming an add-on hardware piece for your iPhone, currently $99 during the campaign.

The main drawback I see is that it "only" goes down to .15 lux, which isn't quite as low as I've measured in actual scenes during tests. However, it also lets you record location and voice notes with each reading, which could be immensely useful in site surveys.

Would you use it?


It's $149 MSRP, what the hell?

A really good calibrated light meter with a USB port for logging is about $120.

Yeah but it doesn't come with a hipster case...

In all seriousness, it does look kind of interesting, just weirdly overpiced.

There's also luxi.

I've seen standard lightmeters run the gamut from $50 to thousands, so saying a plug-in unit for a phone is overpriced at $150 just because another is $120 without quantifying what separates them seems... shortsighted.

Ok, Matt, tell us what the Lumu delivers that a $150 lux meter does not?

The main benefit of the Lumu is that it's small and, if you carry an iPhone, can just use it with that. From it's own specs, it does not appear to be as accurate, especially in low light.

And why would a little plug in, like Lumu, cost more than a complete meter including handheld display? Especially since there is a competitor on Kickstarter, luxi, for a fraction of the price.

Ok, Matt, tell us what the Lumu delivers that a $150 lux meter does not?

I don't have either, so I can't answer that. That's the point.

And why would a little plug in, like Lumu, cost more than a complete meter including handheld display? Especially since there is a competitor on Kickstarter, luxi, for a fraction of the price.

Why are there lightmeters costing hundreds or even thousands of dollars if these cheap option are available?

If you can answer that question, you'll have answered your own question.

Sigh....

Those cheap options are not available. There are kickstarter projects just started this year.

Might it be that the .15 level is a result of the fact that the sensor is so close to the iPhone that has a light itself ?

Or is there an option to measure the light without the screen ebing active ?

Rotate the sensor 180 degrees?

that will help but still the screen will throw light in total darkness !

I am glad you wrote this post, because I just finished a night-lighting assessment during which I juggled back and forth between my paper notebook and my light meter, holding my phone over the notebook so that I could see to write. I never realized that I could have used my Android phone for note-taking! Duh!

Now I'm going to get an armband like my daughter uses for jogging with her iPhone, so I can walk around and dictate notes while taking measurements. I have four night-lighting assessments coming up soon, and I'm really looking forward to them now! Thanks, Ethan!