The paper tries to investigate the question whether photography could be considered as a source of knowledge since the medium has expanded our knowledge about the world, enriching our visual unconscious as Benjamin puts it. Highlighting the objective, mechanical formation of photographic image -not being shared by other forms of visual representation including painting and drawing-anumber of photography thinkers and theorists have acknowledged the relation between photography and knowledge. This mechanical process of image-formation in photography is what makes it different form other techniques of producing pictures. Stressing the idea of transparency, for example Walton argues that photographs like mirrors and telescopes expands our vision. Photographs enable us to see the world through them with seeing regarded as a way of finding out about the world we live in. Photographs not only let us see very tiny or distant things but alsoempower us to seethrough history. Being regarded as document, photography could be regarded as source of knowledge since a photograph could not exist without a referent in the real world. However, photography is not regarded such an objective process by a number of theoristssuch as Sontag and Sekulasince photographer’s mentation effects the formation procedure of thephotographic image through different ways (including point of view, framing, choosing lens…). Moreover, the outbreak of manipulated images and staged photographs due to the advent of digital technology has relatively questioned the realistic, documentary as well as the objective aspect of photography since the digital photography –to some extent- has undermined the objective, mechanical process of the way photographs are formed. However, photographs still prove to be convincingwhile it’s being seen as information carriers by scholars such as Cohen and Meskin. According to Meskin and Cohen, what makes photographs so distinct in regard to epistemic value, is their ability to provide visual information without offering spatial information.Looking at photographs -even digitally produced one-one should note that we still form beliefs about the world we live in, albeit these beliefs need to be confirmed by our common sense,logic and prior beliefs so that they could be turned into knowledge.  Additionally,the survey tries to investigate the difference between photography and other forms of visual representationand image-formation such as painting and drawing especially the most realistic ones known as hyper realistic paintings, keeping pace with photography concerning the ability to capture the finest details.Although the most realistic image-formation techniques such as hyper realistic paintings might represent something in the realworld, they are directly affected by the painter’s mentation and subjectivity.On contrary, photographic images are made in a more objective way with the photographer’s mentation affecting the image indirectly. In addition, hyper realistic images are normally categorized as paintings, not being considered an objective process of image formation by the public audience.Finally, the paper concludes that photography owes its epistemic value to its objective, mechanical process of image formation rather that to its intrinsic realism, though it has always been called a supremely realistic medium. The paper uses analytical-descriptive method with the information gathered using library sources.