Positioning a custom MKAnnotationView

I create a custom MKAnnoationView as follows: ``` - (MKAnnotationView *)mapView:(MKMapView *)theMapView viewForAnnotation:(id <MKAnnotation>)annotation { static NSString* AnnotationIdentifier = @"AnnotationIdentifier"; MKAnnotationView* customPinView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:AnnotationIdentifier]; UIImage *pinImage = [PowerPlantAnnotation getAnnotationImageForEnergySource:((PowerPlantAnnotation*)annotation).energySource]; customPinView.image = pinImage; return customPinView; } ``` I get the image that I want positioned more or less in the right spot, but not quite. My image looks like this: I want the bottom point of the tear drop to point to my annotation map coordinate, like the standard pin view points to the map coordinate. How can I accomplish this? Currently it looks a bit more like my image is centered on the map coordinate.