Context : Aims : Cosmic shear , the gravitational lensing on cosmological scales , is regarded as one of the most powerful probes for revealing the properties of dark matter and dark energy . To fully utilize its potential , one has to be able to control systematic effects down to below the level of the statistical parameter errors . Particularly worrisome in this respect is the intrinsic alignment of galaxies , causing considerable parameter biases via correlations between the intrinsic ellipticities of galaxies and the gravitational shear , which mimic lensing . Since our understanding of the underlying processes of intrinsic alignment is still poor , purely geometrical methods are required to control this systematic . In an earlier work we proposed a nulling technique that downweights this systematic , only making use of its well-known redshift dependence . We assess the practicability of nulling , given realistic conditions on photometric redshift information . Methods : For several simplified intrinsic alignment models and a wide range of photometric redshift characteristics , we calculate an average bias before and after nulling . Modifications of the technique are introduced to optimize the bias removal and minimize the information loss by nulling . We demonstrate that one of the presented versions of nulling is close to optimal in terms of bias removal , given the high quality of photometric redshifts . Although the nulling weights depend on cosmology , being composed of comoving distances , we show that the technique is robust against an incorrect choice of cosmological parameters when calculating the weights . Moreover , general aspects such as the behavior of the Fisher matrix under parameter-dependent transformations and the range of validity of the bias formalism are discussed in an appendix . Results : Given excellent photometric redshift information , i.e . at least 10 bins with a dispersion \sigma _ { ph } \lesssim 0.03 , a negligible fraction of catastrophic outliers , and precise knowledge about the bin-wise redshift distributions as characterized by a scatter of 0.001 or less on the median redshifts , one version of nulling is capable of reducing the shear-intrinsic ellipticity contamination by at least a factor of 100 . Alternatively , we describe a robust nulling variant which suppresses the systematic signal by about 10 for a very broad range of photometric redshift configurations , provided basic information about \sigma _ { ph } in each of \gtrsim 10 photometric redshift bins is available . Irrespective of the photometric redshift quality , a loss of statistical power is inherent to nulling , which amounts to a decrease of the order 50 \% in terms of our figure of merit under conservative assumptions . Conclusions :