Dark Sky Meter App

The app (iPhone only) uses the camera to collect light at night. The aim is to provide a cheap alternative to expensive light meters. When you submit your measurements the data is used for scientific research. The app got awarded by the IDA and has been featured on BBC, CBS and Scientific American.
You can download the app (iPhone 4S and higher) here.
The app is developed by Norbert Schmidt and Harro Treur, and supported by many scientists and the International Dark Sky Association.

App FAQ

Answer

This setting is for people who own a unihedron SQM or SQM-L. If you own a unihedron SQM the calibration on the iPhone can be adjusted to the outcome of the Unihedron Sky Quality Meter. The SQM uses dedicated hardware and is known as the gold standard. You can roughly calibrate the app using the unihedron sqm. iPhones can differ slightly (but constantly). It is best to take a series of measurements using both devices. Example If the SQM shows 20.30 and your iPhone shows 20.15 you can put .15 in the 20.00 and up field. or If the SQM shows 20.15 and your iPhone shows 20.13 you can put -.15 in the 20.00 and up field. Same goes for measurements with sqm 20 or lower, then you should use the 10.0>20.0

Answer

No. There are a lot of different Android devices, more than 4000 in total (2013). With so many camera types on the market, it will be impossible to make a decent Android port of our software. Adapting our software to all cameras will be impossible or cost a fortune.

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Dark Sky Meter is an idea of Norbert Schmidt (software developer) and Harro Treur (engineer). We are amateur astronomers and were looking for a cheap alternative to expensive light meters.

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It is not intended for iPad. Earlier models have a poor camera. And the software cannot discriminate devices (Apple policy).

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The iPhone has a consumer camera and is not designed to collect a lot of light at night. Later models have very sensitive chips, but they aren't as good as the professional, dedicated light measuring devices. On a really dark site, take a minimum of 2-3 measurements and average them.

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You pay 1$ to cover my hosting costs and the many, many hours of private time we spent on it (beer money). You save about $110 for a SQM device.