The first handheld camera was invented in 1888 by George Eastman, it was called the Kodak One. Eventually, the handheld camera achieved enormous popularity in 1910 with the invention of the Brownie Camera. People regularly made remarks about how you couldn't even go outside without having your picture taken. The Single Lens Reflex Camera was invented in 1933, which became the standard model for the cameras used today. The Single Lens Reflex or SLR camera included interchangeable lenses and film that could be removed without shipping the whole contraption to the manufacturing facility. The SLR was eventually replaced by its digital counterpart, the Digital SLR, which was invented in 1976 and had only .64 Megapixels. As the early stages of camera technology developed, representational painters were forced to produce non-representational art. By the mid-1900's, the representational painting had almost disappeared. But something happened in the 1970's. In my opinion, representational artwork had not reached its pinnacle until the 1970’s and it’s largely because of innovations in Camera technology.
Photo-realism as an art form was an utter impossibility without the invention of the camera because as the name implies, Photo-realism requires the use of a photograph. The projector also drove the development of Photorealism by allowing the artist to accurately replicate a photograph structural lines onto a painting surface with ease. These two innovations explain why photorealism happened in 1970 instead of 1870, and could not have happened in 1870. The argument that photorealists paint like renaissance painters is inaccurate.
The human eye is the equivalent of a 576 megapixel camera. So while photography may have created photorealism, the human eye still outperforms even the best cameras in terms of megapixels. Also, cameras may be able to interpret more bits of color than the human eye, but cameras interpret it differently than the human eye. This is how Hyper-realism emerged. Hyper-realism is a step further from photo-realism, while a hyper-realist may utilize the same techniques as a photorealist, the hyper-realist often works from a mixture of life and photographs because of lens distortion, the difference in bits of color, and unintentional lens curving.
The are other differences between the photorealists and ‘traditional’ realists which should be obvious, but I regularly hear people talk about photorealism, like it’s how Michelangelo painted. To clarify, Renaissance painters mostly painted things that never existed, such as gods and mythical figures. On top of creating imaginary scenes, the artists rarely worked from life. Some of the greatest painters of all time, like Michelangelo and Raphael, are notorious for making up muscles in their figures. Caravaggio may have been one of the few painters to work from life and he is often called the first modernist.
Much like the Abstract Expressionism, the point of photorealism is not to trick you into thinking that you’re looking at 3-dimensional space (like the classical renaissance realist), but to demonstrate the limit of the medium itself. Photo-realism also challenges the ideological root of art movements in a postmodern fashion, instead of painting transcendence, like the transcendence found in Abstract expressionism, the photorealist paints a bus stop, instead of using color to express emotion, the photo-realist paints the mundane, instead of creating an angelic scene, the photorealist paints life. Photorealism is the synthesis of photography and painting, as a reaction to Abstract Expressionism. I think it’s comical how art historians forget to mention that the Photorealist movement revolutionized art education, and how the photorealist movement occurred after Abstract Expressionism. Which fundamentally questions whether or not Abstract Art was truly the “End of Art”.
 Gustavson, Todd. In Camera: A History of Photography from Daguerreotype to Digital, 124. 2nd ed. Vol. 1. New York: Sterling Innovation, 2009. pg. 129
 IBID,... pg. 146
 Arnason, H. Harvard. History of Modern Art: Painting, Sculpture, Architecture. New York: H.N. Abrams, 1968.
 Gustavson, Todd. In Camera: A History of Photography from Daguerreotype to Digital, 124. 2nd ed. Vol. 1. New York: Sterling Innovation, 2009. pg. 322
 "The Human Eye Specifications - 576MP!" : Open Talk Forum: Digital Photography Review. April 1, 2010. Accessed November 13, 2014. http://www.dpreview.com/forums/thread/2791860.