Reducing the shear

As gravitational lensing measurements become increasingly precise, it becomes necessary to include higher order effects in theoretical calculations. Here we show how the difference between the shear and the reduced shear manifest themselves in a number of commonly used measures of shear power. If we are to reap the science rewards of future, high precision measurements of cosmic shear we will need to include this effect in our theoretical predictions. (c) 2005 Elsevier B.V. All rights reserved.