Grey on televisions, computer displays and telephones is usually created using the RGB color model. Red, green, and blue light combined at full intensity on the black screen makes white; by lowering the intensity, it is possible to create different shades of grey. In printing, grey is usually obtained with the CMYK color model, using cyan, magenta, yellow and black. Grey is produced either by using black and white, or by combining equal amounts of cyan, magenta and yellow. Most greys have a cool or warm cast to them, as the human eye can detect even a minute amount of color
Combination printing would be able to combine the two negatives by blending them together. Photographers such as William Frederick Lake Price and Oscar Rejlander are famous for using combination printing. Starting as early as the mid-19th century, new methods such as the combination printing, began to change the way people looked at different photographic techniques. Controversy broke out in the photographic community about the use of combination printing. Photographs originally had been regarded as truth and it was perceived that the camera never lied. However, with the newfound ability to manipulate the final product, the notion that photographs depicted "truth" was soon