[Plugin: Geotag] How to activate?

I installed Geotag and went through the configuration process. On my Add New Post page, a map appears but there are fields for “Search for an address” and “Latitude, Longitude.”

I thought the plugin read the geotagging info from my photos and displayed them on a map automatically but that’s not happening. The only time a map appears in my posts is when I enter an address or latitude and longitude.

Am I doing something wrong? Or do you have to enter the location info for each photo? I thought it was automatic. Thanks for any assistance.

http://wordpress.org/extend/plugins/geotag/