Preheat oven to 400 degrees F.
Crisp pizza crust 5 minutes on perforated pizza pan or on oven rack.
While pizza crust is in oven, mix sour cream with lemon juice and dill in a small bowl.
Remove pizza shell from oven and let stand until cool to the touch. You have a pocket of time here to work on other recipes.
On cool, crisp pizza shell, spread the sour cream-dill sauce in an even layer. Evenly distribute sliced smoked salmon, working all the way to the edges.
Top pizza with sliced cucumber, red onion, and capers.
To serve, cut pizza in 1/2. Cut each 1/2 in 1/2 again, 4 cuts across. Turn the pan a 1/4 turn and slice into quarters, making 16 cuts.