Overall, the results of this study support the hypothesis that digital imaging offers a statistically significant improvement in the perceived image quality compared with 35-mm slide film when controlling for variations in subject matter, lighting, distance to the target, lens used, and sensor size. In particular, sensor size is a very important variable whose impact has not been considered in the previously cited studies. When the sensor in a digital camera is smaller than a frame of 35-mm film, the image is recorded using only the central portion of the lens, narrowing the angle of view.15,16 This makes standardization of the reproduction ratio difficult and requires that the digital camera be farther from the subject than the film camera. To date, only very few digital cameras have been produced that have sensors the same size as a frame of 35-mm film. These are the Kodak (Rochester, New York) DCS SLR introduced in 2004 (now discontinued), the Canon EOS 1Ds series (2002 to present), the Canon EOS 5D series (2005 to present), the Nikon D3 series (2007 to present), and the Nikon D700.