The Luxi for All is a light meter accessory for smartphone and tablet light metering apps. It turns the camera of your mobile device into an incident light meter.
Luxi for All is a plastic half dome mounted on a clamp. The dome is made of semi-transparent neutral white plastic. The mount has a spring-loaded mechanism that allows you to mount the Luxi for All on iPads, iPhones and other mobile devices with or without a case (up to a point, of course — you have about a centimetre thickness to play with). The dome is large enough to fit around your device’s camera, but you must make sure to mount it so there isn’t any vignetting.
I tested the Luxi for All with my iPad Air 2 wrapped inside its Apple Smart Case. ExtraSensory Devices developed a free app to go with the Luxi for All accessory, but I used Cine Meter II instead. I did briefly try the Luxi app and it certainly does the job if all you need is exposure/aperture measuring, but if you want to get more out of your Luxi for All, it’s best to buy the Cine Meter II app by Adam Wilt. For starters, the Luxi app only works with the front camera (the one facing you). In addition, Cine Meter II is the most complete app you can buy.
I was a bit worried the Luxi for All would scratch the glass surface of my iPad, but specifically on an iPad, the back camera sits tucked away in a corner and even if it would scratch the oleophobic coating or the glass itself, it wouldn’t be catastrophic.
Anyway, I needn’t worry at all, because the Luxi for All doesn’t scratch at all. Also note that I used the Luxi for All with the back camera, while it’s advertised as an accessory to be used with the front one. There’s a silicon rubber bumper resting on the glass when you use it as advertised.
The Luxi for All seems strong enough too. I wouldn’t recommend putting it on and taking it off every five minutes of the day for weeks on end, but that’s probably not what you want to do if you’re going to be serious about light metering. You’ll most likely use an older idevice or have an iPod Touch especially purchased for the occasion. While the Luxi for All and Cine Meter II combination can’t measure strobe light — you’ll need the upcoming Lumu Power for that — it does make for a very complete, very accurate light meter at a price no “real” light meter can compete with — just €30 for the Luxi for All and €25 for Cine Meter II.