In order to compensate you must stand at the very edge of the platform (there are platforms?) and curl your toes around the very lip of the last plank and then with absolute conviction shout that you repent for all your sins, and then pay $30 compensation, to me, and I will absolve you of those sins. Dinu may be the “king” but I am the Eminence Gris. You may now kiss my ring.
All fantasy aside, in order to compensate for a very bright background that dictates what your camera’s built-in light meter registers and then commands the camera’s settings in an attempt to provide a well-exposed water surface, you must deliberately re-set the f-stop to the right of what the meter proclaimed to be correct, thereby opening the iris to let in more light (despite the bright background) so that your precious subject (the merganser) gets enough exposure. This shift to the right can be done by pushing and holding down the back button that says “Av” while turning the front dial so that the exposure scale at the bottom of your viewfinder shows a shift to the right side of about a full f-stop, sometimes slightly less, sometimes slightly more. You can find tune the compensation shift by checking the image on your live-view screen by pressing the preview button. If the merganser is still under-exposed then press the Av again and dial in more light. The water, or sky will be over-exposed but there are mitigating technique in photoshop to offset some of that blow-out. Don’t forget to re-set the setting back to normal, or better yet, for most shooting conditions … 1/3 stop, or 2/3 stop to the left (other side of the middle). This helps mitigate highlight blow-out that often happens when the iris has not been compensated at all (center position on the sliding scale).