Eliezer Nieves Rodriguez leads students on a bird Census at the San Juan Bay Estuary via boat with Univ. of PR Human Geography students. Eliezer-Birds Census on a boat tour with UPR Human Geography students Technical Details Camera: Canon PowerShot G7 X Taken: December 14, 2017 Focal length: 8mm Aperture: f/6 Exposure: 1/1,250 second ISO: 250