What is the test for "objectively reasonable" use of force in a civil case?

The reasonableness of an individual's use of force is reviewed "from the perspective of a reasonable officer on the scene, rather than with the 20/20 vision of hindsight." Graham v. Connor, 490 U.S. at 396, 109 S.Ct. 1865. Moreover, the "calculus of reasonableness must embody allowance for the fact that police officers are often forced to make split-second judgments ... about the amount of force that is necessary in a particular situation." Id. at 396-97, 109 S.Ct. 1865. Nonetheless, this test is "an objective one: the question is whether the officers' actions are 'objectively reasonable' in light of the facts and circumstances confronting them, without regard to their underlying intent or motivation." Id. at 397, 109 S.Ct. 1865.