My sense of proportion has been hopelessly corrupted by a lifetime of telling girls that six centimeters is actually six inches, so I’m very excited by the prospect of an app that can tell me the size of something just by taking a photo of it.
That app is called CamRuler, and it works by comparing the size of an unknown object to that of a known object. If you ever put a coin or a small model dinosaur into a photo to help show scale, then you already know how it works.
The app comes loaded with a reference library of the sizes of common objects: Coins, paper money, common paper sizes are all in there, so if you snap a picture of — say — a Galaxy Note next to a quarter, the app will tell you its measurements (answer: too big. Way too big).
You can also enter your own references, if you use some weird old money, or use a barter system. It can be calibrated to use custom scales, too, so you can marry it up to a paper map and have it calculate route distances for you, in both metric and imperial, from nanometers to nautical miles.
Caveat: You’ll need to keep the reference and subject in the same plane, i.e. you’ll need to snap your pictures from above as if you were scanning them. But as many of us use our iPhones to scan documents anyway, we can totally manage that, right?
The app is universal, and costs just $2. I’m going to grab this and keep it ion the Utilities folder on my home screen for next time somebody questions my estimates.