First Impressions: Lumu Power Light Meter

Last year, Lumu launched a Kickstarter for a brand new Light meter for the iPhone that would be able to meter color, ambient light, and flash output. For anyone that uses a light meter of any sort, this sounds wonderful (sans being able to trigger a monolight via the meter). At Photokina 2016, I finally got the chance to see their unicorn product: the Lumu Power. The company claims that it will be delivered this November, and that they’ve had a number of holdups along the way. Sure, they’re late on delivering their Kickstarter promises, but they’re now ready to get it out to the public.

Tech Specs

Specs taken from the product page


  • Measuring range: 0.15 – 250,000 lux
  • Accuracy: +/- 3%
  • Flat Diffuser, Cosine-type response


  • Power source: iOS device
  • Materials: Housing: Stainless Steel, Diffusers: Polycarbonate Lexan
  • Compatibility: iOS devices using Lightning connector, running iOS 8+


  • Measuring range: EV -4 to 20 at ISO 100
  • Accuracy: +/- 0.1 EV
  • Light receptor: fast-response Silicon photo diode, CIE spectral luminous efficiency
  • Hemispherical Diffuser, Cardioid-type responses

Color (Temperature)

  • Light receptor: True Color Sensor, CIE 1931 Color standard Human eye perception
  • Sensitivity: Visible light
  • Dynamic range: 1:1,000,000
  • Accuracy: < 0.6 deltaE, Repeatability: < 0.2 deltaE
  • Flat Diffuser, Cosine-type response



The Lumu Power is quite a bit larger than the original Lumu light meter. One side is a rounded dome-like area that looks similar to pretty much any dome you’d see on a more conventional light meter.


The other side is a flatter area designed not only for ergonomic reasons but also because it helps to discern colors in a scene. Like all light meter domes, it’s best to keep it as clean as possible. So Lumu also comes with a smallish case to place it in when not in use.


Lumu Power plugs right into the iPhone by using the lightning connector. This is perfect for iPhone 7 and iPhone 7 plus users.

Build Quality


In the hand, the Lumu feels pretty solid. What I held is a prototype that the company says is in beta; but is still pretty close to the final version.

Ease of Use


The Lumu Power works with an app that lets you control various parameters like you would with a regular light meter. It will work great with film cameras and studio strobes. When in the color reading mode, it will actively give you a live read out of the colors in the scene. Here’s one readout.


And another…


And yet another.


The new app will also take all of the previous Lumu apps and combine them into one. So you’ll get to do lots of things with one app. This includes stuff like pinhole camera readings, ambient light exposures, etc.


But the biggest and best new feature has to do with reading flash output values. When you set the light meter to be ready, and then pop a flash at the meter, it will read the light output then figure out what you’ll need to set your aperture to.


One of the cooler things that the light meter does is give you the reading of the flash duration–which is huge if you’re trying to figure out how you can overpower the sun when shooting outside. For monolight users and strobist, this will be a huge help.

First Impressions

The Lumu Power seems quite promising; and if the company can deliver on its promise of a November release and get it into the hands of the right people (like David Hobby or Zach Arias), then it’s bound to be a big hit with people. It’s already a hit with the analog photography community and color junkies.

We’ve called in a review unit, and we’re supposed to be getting ours a bit before launch. We’ll have a full review coming soon.

Chris Gampat

Chris Gampat is the Editor in Chief, Founder, and Publisher of the Phoblographer. He also likes pizza.