An inspection system comprising: a source configured to generate inspection radiation having a radiation dose; a collimator configured to collimate the inspection radiation into an inspection beam configured to irradiate a section of a vehicle; a filter located between the source and the collimator, the filter having at least: a cargo configuration where the filter is configured to interact with the inspection radiation to provide a cargo inspection dose for inspection by irradiation of a container of the vehicle by the inspection beam, the container being configured to contain cargo, and an attenuation configuration where the filter is configured to attenuate the radiation dose to a cabin inspection dose reduced compared to the cargo inspection dose yet enabling inspection by irradiation of a cabin of the vehicle by the inspection beam, the cabin being configured to be occupied by a user; and a controller configured to control the configuration of the filter, such that the filter is: in the cargo configuration when the inspection beam irradiates the container, and in the attenuation configuration when the inspection beam irradiates the cabin, characterized in that the source and the collimator comprise respective casings, and the filter comprises a casing which is distinct from the respective casings of the source and the collimator. a source configured to generate inspection radiation having a radiation dose; a collimator configured to collimate the inspection radiation into an inspection beam configured to irradiate a section of a vehicle; a filter located between the source and the collimator, the filter having at least: a cargo configuration where the filter is configured to interact with the inspection radiation to provide a cargo inspection dose for inspection by irradiation of a container of the vehicle by the inspection beam, the container being configured to contain cargo, and an attenuation configuration where the filter is configured to attenuate the radiation dose to a cabin inspection dose reduced compared to the cargo inspection dose yet enabling inspection by irradiation of a cabin of the vehicle by the inspection beam, the cabin being configured to be occupied by a user; and a cargo configuration where the filter is configured to interact with the inspection radiation to provide a cargo inspection dose for inspection by irradiation of a container of the vehicle by the inspection beam, the container being configured to contain cargo, and an attenuation configuration where the filter is configured to attenuate the radiation dose to a cabin inspection dose reduced compared to the cargo inspection dose yet enabling inspection by irradiation of a cabin of the vehicle by the inspection beam, the cabin being configured to be occupied by a user; and a controller configured to control the configuration of the filter, such that the filter is: in the cargo configuration when the inspection beam irradiates the container, and in the attenuation configuration when the inspection beam irradiates the cabin, in the cargo configuration when the inspection beam irradiates the container, and in the attenuation configuration when the inspection beam irradiates the cabin, characterized in that the source and the collimator comprise respective casings, and the filter comprises a casing which is distinct from the respective casings of the source and the collimator.