Slice eggs in half lengthwise, carefully remove yolks and set whites aside.
Press yolks through a fine mesh strainer into a small bowl. In the bowl of a food processor, combine mayonnaise, sour cream, smoked salmon, Dijon mustard, lemon juice, capers, lemon zest, salt and cayenne pepper and pulse until well combined and fairly smooth. Add the egg yolks and process for another minute.
Transfer egg mixture to a piping bag and pipe filling into the well of each egg white.