Della Porta claimed to have shown such spectacles often to his friends. They admired it very much and could hardly be convinced by Della Porta's explanations that what they had seen was really an optical trick. Although there seem to be few records of the camera obscura being used for such elaborate spectacles, the scarier kind of "magic" was probably more or less commonplace by the start of the seventeenth century, mainly with actors portraying the devil, demons, witches or ghosts.