If you have an iPhone, PhotoCalc may provide you with a handful of photographer’s tools without having to carry around any reference materials. The iPhone application from Adair Systems offers a whole list of calculators for both professional and hobbyist photographers, as well as several reference documents that a photographer might need to consult on the job.

The calculators include the following:

• Exposure Reciprocation
• Depth of Field and Hyper-focal Distance
• Flash Exposure
• Sunrise/sunset/solar noon

You can configure PhotoCalc to use English or metric units as well as half or third stops.

PhotoCalc is priced at $3, not bad for what looks like an excellent reference tool that happens to fit in your pocket.