Puree raspberries using a food processor or blender until smooth. (Add in a little water if needed depending on the power of your blender).

Squeeze raspberry puree through a fine mesh strainer to remove any pulp and seeds and pour into a large pitcher.

Combine sugar and 1 cup of water in a small sauce pan.

Cook over medium heat until the sugar is completely dissolved.

Pour simple syrup into the pitcher.

Pour remaining water and lemon juice into the pitcher. Stir together.

Serve over ice.