I’ve written about some fantastic iPhone/iPod/iPad applications for video professionals in the past, and my list just keeps growing. I was dubious when I first heard about Nuwaste Studios’ Pocket Light Meter—it sounded like a silly app like a fingerprint scanner or x-ray vision—but the info page for Vladislav Vyshemirsky’s application seemed legit enough for me to give it a test run. I worked with version 6.0 on my iPhone 4. It’s a 2.8MB sized file—and it’s a free app.
The app uses the iPhone’s camera as a spot meter and—unbelievably—it’s incredibly accurate! Comparing readings with my Sekonic L508C spot meter, I found the Pocket Light Meter to be within 1/10th of a stop every time. Using a gray card, I could quickly turn the Pocket Light Meter into an incident meter.
The setup page gives you several options. You can set your shutter speed to indicate full, half or third stops or set it for cine speeds. You can set your aperture and ISO stops into full, halves and thirds as well. There’s even an option to log your readings to your Dropbox account for future reference. If the meter is slightly off or if you need to calibrate to a second meter, there’s a simple slider for EV correction factor that allows you to do your own calibration.
The app works with either the forward or backward camera on the iPhone (or iPod). You have a small viewfinder-like image that shows you what the camera is seeing and a red open rectangle that indicates the reading area. You can touch the viewfinder area to move the reading area to wherever you’d like if the center isn’t what you need to read.
Within the viewfinder is optional “additional information” that gives you EV number at your current ISO and at 100 ISO, lux and footcandle readings.
Below the viewfinder are boxes that display shutter speed, F-stop and ISO.
Touch the shutter speed box to select between a 32-second exposure and 1/8000th of a second—an incredible range. Cine speed is a little more awkward as it’s not actually represented in frames per second, but still in shutter speed. So you see 1/24, 1/32, 1/48, 1/96, 1/180 and 1/360. Assuming a 180-degree shutter, these would be 12, 16, 24, 48, 90 and 180 frames per second. ISO selection is from 6 to 102,400—again, an incredible range of options, beyond the range of my Sekonic.
There’s a “log” button that takes a screen shot of the viewfinder image with data that represents your shutter speed, F-stop, ISO and date and time of the reading.
The meter is always reading, so it’s handy to have a “hold” button: point it at the area you want to read, hit “hold” and then move the phone to look at the reading information and evaluate your exposure.
I was surprised at the precision of this app. It is a very legitimate, workable tool. For iPhone/iPod/iPad digital shooters who think meters are too expensive or not necessary, this app is the right price to explore the power of the light meter on your set. Perhaps it will make a convert out of you. This app is useful on the iPad, but less so as the size of the pad makes taking readings a little too cumbersome. The iPhone or iPod is the perfect handheld size to make a viable spot meter.
Nuwaste Studios Pocket Light Meter
Pros: Very accurate, great range of sensitivities.
Cons: Because it’s a free app, you have to deal with annoying, but ignorable, ads at the bottom of the screen.
Bottom Line: A phenomenally useful application in your pocket. Shouldn’t replace a real meter, but it definitely works in a pinch!
Available at Apple’s App Store