diff --git a/carto/proj_albers_equal_area_conic.go b/carto/proj_albers_equal_area_conic.go
index 52296d85..40c52d26 100644
--- a/carto/proj_albers_equal_area_conic.go
+++ b/carto/proj_albers_equal_area_conic.go
@@ -16,7 +16,8 @@ type AlbersEqualAreaConic struct {
 }
 
 // NewAlbersEqualAreaConic returns a new AlbersEqualAreaConic projection with
-// the given earth radius.
+// the given earth radius. The standard parallels are set to 30 and 60 degrees
+// north.
 func NewAlbersEqualAreaConic(earthRadius float64) *AlbersEqualAreaConic {
 	return &AlbersEqualAreaConic{
 		radius:       earthRadius,
@@ -32,7 +33,7 @@ func (c *AlbersEqualAreaConic) SetStandardParallels(lat1, lat2 float64) {
 }
 
 // SetOrigin sets the origin of the projection to the given (longitude,
-// latitude) pair. The origin have projected coordinates (0, 0).
+// latitude) pair. The origin has projected coordinates (0, 0).
 func (c *AlbersEqualAreaConic) SetOrigin(origin geom.XY) {
 	c.origin = origin
 }
diff --git a/carto/proj_equirectangular.go b/carto/proj_equirectangular.go
index c15a0ebf..dc9eab2e 100644
--- a/carto/proj_equirectangular.go
+++ b/carto/proj_equirectangular.go
@@ -6,8 +6,8 @@ import "github.com/peterstace/simplefeatures/geom"
 // pairs via the equirectangular projection.
 //
 // The equirectangular projection is a cylindrical projection that is:
-//   - Configured by setting the central meridian and two symmetric standard
-//     parallels.
+//   - Configured by setting the central meridian and two standard parallels
+//     that are symmetric about the equator.
 //   - Not equal area, but preserves area locally at the standard parallels.
 //   - Not conformal, but preserves shape locally at the standard parallels.
 //   - Not equidistant, but preserves distance locally at the standard parallels.
diff --git a/carto/proj_orthographic.go b/carto/proj_orthographic.go
index 77d305ed..8637df4f 100644
--- a/carto/proj_orthographic.go
+++ b/carto/proj_orthographic.go
@@ -5,9 +5,9 @@ import "github.com/peterstace/simplefeatures/geom"
 // Orthographic allows projecting (longitude, latitude) coordinates to (x, y)
 // pairs via the orthographic projection.
 //
-// The orthographic is a projection where the sphere is projected onto a
-// tangent plane, with a point of perspective that is infinitely far away. It
-// gives a view of the sphere as seen from outer space.
+// The orthographic projection projects the sphere onto a tangent plane with a
+// point of perspective that is infinitely far away. It gives a view of the
+// earth as seen from outer space.
 //
 // It is:
 //   - Configured by setting the center of the projection.
@@ -31,7 +31,7 @@ func NewOrthographic(radius float64) *Orthographic {
 	}
 }
 
-// SetCenterLonLat sets the center of the projection to the given (longitude,
+// SetCenter sets the center of the projection to the given (longitude,
 // latitude) pair. The center have projected coordinates (0, 0) and be the
 // center of the circular map.
 func (m *Orthographic) SetCenter(centerLonLat geom.XY) {