There are a number of sun angle software applications available for the iphone: PhotoPills; Sun Servey; Sun Seeker; Helios and LightTrac. I have found LightTrac to be very easy to use once you have a data connection on the iPhone.

Here is how Light Trac describes its benefits and features: “Quickly determines at what time and location the light conditions are perfect to shoot your subjects outdoors. The elevation and angle of Sun changes throughout the year depending upon the location, date as well as the time of day. Light Trac calculates both the elevation and angle of Sum and Moon for any date & time, for any place on earth and plots it on top of a satellite map. Armed with this information and with an extremely easy to use interface, you can now plan your photo shoot even several months ahead of time and position yourself at the right spot at the right time for the perfect shot

Features include:

  • Universal app works on iPad, iPhone and iPod touch
  • Scout for new locations using a map for perfect sunlight angle or for a backdrop with a rising/setting moon
  • Find Angle and Elevation of Sun for any location and time
  • Find Angle and Elevation of Moon for any location and time
  • Find Sunrise, Sunset and Twilight times for any day
  • Find Moonrise, Moonset and Moon Phase for any day
  • View exact date and time when Full Moon, New Moon, First quarter and Last quarter occurs
  • View elevation chart and azimuth chart for Sun and Moon
  • View the length of shadow for any elevation at any time
  • Integrated compass view on the iPad
  • Search locations by address, city or zipcode
  • Save multiple locations and switch between them easily
  • Use address book to pick locations from your contact’s addresses
  • Share your saved locations easily with fellow photographers via email
  • Easily export your locations to KML file to view on other apps
  • Does automatic timezone detection
  • Available in English, German, French & Japanese

The software costs US$8.99 on the Apple Store.