Presentation on theme: "A comparison of black and white film and digital photography through grain and noise Chris Betts Mentored by Mr. Norman Tracy Introduction Recently, digital."— Presentation transcript:
A comparison of black and white film and digital photography through grain and noise Chris Betts Mentored by Mr. Norman Tracy Introduction Recently, digital photography has advanced to a point where it rivals film based photography. However, there seems to be little or no evidence of which media produces images of superior quality. There are many arguments about what makes one media better than the other. There are the obvious arguments for digital photography and the ability to view the photographs the moment they are taken and the ability to upload them straight to a computer. This is really a matter of convenience rather than quality. In the same way, film has arguments that support its superiority. One of the positive attributes of film photography is the level of detail that can be captured. In digital photography, the term megapixels is used as a measurement of the number of particles that hold detail in a set area of the photograph. Film has a much greater level of detail than even the best digital photographs because film catches images through the silver grain that makes it light sensitive, which are much more fine than the pixels that digital photography must deal with. However, the number of megapixels only matter when creating very large prints, which are generally only made by people who have cameras which invalidate this argument. There is one measure of a photograph’s quality that has not been researched. This is known as grain in film photography and noise in digital photography. They are generated in different ways in their respective media, but create the same visual effect when viewing the printed photograph. The observed effect is a variation in color and light from what the actual image in front of the camera originally displayed. Noise and grain can be judged through computer programs and human opinions equally, due to their nature. However, they vary in accordance with a film’s speed(Upton, 1985). In addition, digital cameras include film speed to match film cameras (Sienkiewicz, 2009). The purpose of this study is to determine which media is better visually by evaluating the noise and grain numerically and through subjective opinion using surveys. Materials and Methods Photographs were taken with both film and digital cameras under identical conditions to minimize confounding variables. The photographs were shot in an environment that allowed for control of lighting, position, and subject. The two cameras used were Nikon ® D3000 Digital SLR and Pentax K1000 Film SLR cameras Results The data collected through ImageJ showed the standard deviation of the film images and digital images were different, but mostly within the same range with film’s range being slightly lower for films speeds of ISOs 100 and 400, as shown in figures 1 and 2. However, when the ISO 1600 film was examined it showed a higher standard deviation than its digital counterpart. Each area measured showed a greater standard deviation value, as shown in the Figure 3. The survey was used to determine which image, figure 4 or figure 5, students of Aberdeen High School thought was better, not being told which was digital or film. Of the 197 responses, 64.0% gave reasons for their choice irrelevant to the study, such as slight differences in perspective or sizes. Of the remaining 36.0% of responses, 93.0% preferred the digital image over the film, with only 7.0% supporting the image produced by film. Conclusions The results gathered through ImageJ show that film and digital perform similarly in the lower film speeds, with film performing only on average 4.91 better than digital. Higher films speeds, showed less standard deviation. When taking photographs higher film speeds are helpful, because they allow the photographer to take pictures in low light situations where lower film speeds produce extremely dark photographs. The only drawback to higher film speeds is the grain or noise it generates. Lack of noise and grain generation would be a highly desirable trait for higher film speeds, meaning the digital images in this speed range are of a greater quality, as demonstrated by the standard deviation values in Figure 3. The survey unfortunately did not return as reliable of results as hoped. The decision to ask which image was better and simply root out the irrelevant responses resulted in less than half of the responses being usable, making the entire process incredibly inefficient, as well as leaving additional room for human error. Despite these difficulties, the relevant responses obtained through the survey were, in large part, supporting the digital photograph’s clarity. With such a large ratio preferring the digital photograph there is little margin for error, even with only 71 viable responses given. Together, both the imageJ and the survey results support digital photography as performing greater in terms of quality and clarity at ISO 1600. This could be due to increased noise cancelling software in digital cameras or some other passive feature; however, the results show digital photography performs better than film. Materials and Methods (Continued) with Kodak Black and White films of ISOs 100, 400, and 1600. The photographs were then developed and uploaded to a computer for analysis. Using the program GIMP, the photographs were aligned to a base photograph, and then loaded into ImageJ. In ImageJ, various areas of the photographs were examined to determine the standard deviation of noise and grain contained within the images. Two of the ISO 1600 photographs, one from the digital set and the other from the film, were selected for printing in order to be used in the survey. The two images were shown to various students at Aberdeen High School, asking them which they thought was better, and why, so as to eliminate irrelevant responses. The two data sets were compared to look for any pattern of data that identified a particular photograph as being better in both measures in order to conclude which medium is better. Figure 4-Digital Figure 5-FilmFigure 6-The set up used References Sienkiewicz, J. (2009). Missing Page: ISO Setting. Retrieved from http://photo.net/column/jonsienkiewicz/missing-pages-column/iso- setting/ Upton, B. L., & Upton, J. (1985). Photography (3 rd ed.). Canada: Little, Brown, & Company. Figure 1 – Std. Dev. Figure 2 – Std. Dev.Figure 3 – Std. Dev.