Lumu Light Meter Review

The Lumu light meter is small, portable and you can even wear it as a necklace! At $149, anyone can have the power of a professional digital light meter in their hands all the time. But is it really accurate? And how is it in practice?

The Good

Upon opening the Lumu, you’ll be shocked at how tiny it is. The sensor is about the size of a quarter and simply plugs right into the headphone jack of your iPhone.  

There are currently three apps you can use with the Lumu, though additional third-party apps are likely in the works. The first is Lumu, the base application. The others are Video, designed for DSLR videographers, and Pinhole, based on pinhole cameras.

The Lumu is surprisingly accurate. When compared with a Sekonic L-358 light meter, the results were identical. We’ve used the Sekonic for 5 years with consistently perfect results, so you can count on your exposures being spot on.

The Lumu is also quite versatile. Not only do you get exposure information, but you can also measure light in lux. This means you can test your individual lights to see if your bulbs are getting faded, or even test out a projector to judge its condition. We used this meter to test the LitePanels Sola 9 for its review to see how many lux it was outputting.

Stylish storage pouch and necklace strap included
Stylish storage pouch and necklace strap included
And it’s extremely portable! Combined with how tiny it is, it comes with a small leather pouch which you can attach to your camera strap. Also included is a necklace holder — the headphone plug goes into a sleeve on the necklace. How cool is that? You’ll get a lot of comments on your unusual necklace, and you can respond by showing that it is actually functional!

The Lumu is surprisingly accurate…also quite versatile.

No batteries required. The Lumu’s sensor is powered directly from the headphone jack of an iOS (6 or later) device. We can’t tell you how many times shooters get out to a location only to find their expensive lithium batteries are dead, forcing them to use in-camera light meters. So, if your iOS device has power, the Lumu has power. No fuss.

The Not-So Good

At first blush, we were frustrated by the Lumu. It didn’t fit with an otter-box (which is understandable), but when plugged into a naked iPhone 5, it didn’t work either. We had to back out the plug slightly to make it work properly. Why? Because it’s designed to work with the more-popular backplate-style iPhone cases. So, if you use a backplate case — no worries. The Lumu should fit perfectly.

Not Great for Studio Flash Photography – After hearing about the convenience and portability of the Lumu, you may be asking yourself why anyone would bother with a traditional light meter like a Sekonic. Well, the short answer is that a Sekonic can activate your flash array. Between wireless options and a plug for studio flashes, a Sekonic can give you an accurate exposure for still photography. The Lumu measures constant light, though there are modes to measure “max light” in the lux panel. For still photography, you’ll want a reading that is taken in the instant flashes pop. However, the Lumu does work great for video lights, and as the title of this magazine is “Videomaker” not “Photo Shooter,” the Lumu will work great for our readers.

No Uni-directional Light Reading – Most light meters can recess the sensor dome, or even replace it with a lens. This allows for readings from a single direction for a variety of purposes. The Lumu gets a global reading with its hemispherical sensor. Again though, global readings are far more useful for general videography, so it should work great for our readers.

Tiny is a two-edged sword – How many times have you lost a quarter? Dropped it down a drain pipe? Even lost tiny parts in your camera bag? You’ll definitely need to keep track of this device. Again though, the necklace strap is an awesome way of doing this, so hopefully it wouldn’t be a problem for the average user.


We have to be fair here. A light meter that provides convenient and accurate readings for $149? We were skeptical. Another iOS app for video production? We rolled our eyes.  But it worked. It worked really well. If this author didn’t already have the Sekonic, I’d be buying one today.

In the future, we’d like to see a version with a plug on the back of the sensor for triggering flashes. If it had that — watch out light meter industry; you’re outdated. For now however, this is an amazing alternative for videographers and cinematographers looking to slim-down their gear bags a bit.

So, is it perfect? No. But at $149, the usefulness vastly outweighs the cost. So, we wholeheartedly recommend the Lumu as the next addition to your equipment wishlist.

Ty Audronis is a video/film professional with more than 20 years of experience. Ty has worked on national television, film and even planetarium presentations.

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