The best defence to a voyeurism charge will depend largely on the circumstances of the case. However, one common defence to this charge would be to argue that there was no reasonable expectation of privacy where the observation or recording took place. For example, an accused cannot be guilty of voyeurism if they take a recording of people without clothes on a nude beach. In that particular scenario, because the complainants are in a public setting where they can expect to be within the view of others, they could not have held a reasonable expectation of privacy. Without the violation of a reasonable expectation of privacy, there can be no offence.
Another common defence to a voyeurism charge would be to argue that the observation or the recording was not done for a sexual purpose. For example, it could be possible that the recording was being made to surveil and area for security or artistic reasons and the recording of the complainant was accidental. In such a circumstance the person accused with the crime would lack the mental intent necessary to be guilty of the offence.
Another effective way to challenge a voyeurism charge would be to argue that the evidence against you was obtained in violation of the rights and freedoms guaranteed to you by the Charter. For example, it could be the case that the police found the recording while conducting an illegal search of your phone or computer. In such an event, you can defend your charges by arguing that the illegal search was a serious violation of your section 8 Charter right to be free from unreasonable search and seizure. In the event that this motion is successful, you can argue that all evidence gathered in violation of your rights should be excluded from your trial. If the evidence that is excluded is the recording, it may be enough for you to be acquitted from your charges.