----- Grain and Grain Reduction - January 16, 2012 -----
I'd like to take a moment to write about grain. Grain is a fundamental part of all photography. It's been there since the beginning and it's even made the jump to the digital age. Well, kind of.
In film, grain is physically visible due to the use of silver-halide particles. These particles are what make film sensitive to light. Low speed film uses less of these particles and has very fine, barely observable grain when moderately enlarged. However, when using high speed film you increase the size and amount of visible grain. It's a trade-off. More film speed = More grain. Less film speed = Less grain. While low speed film is harder to shoot, as it requires more light to properly expose, I often prefer the cleaner pictures it produces.
With digital photography, grain does not exist in the same capacity. Digital grain, or more correctly known as 'image noise', is a result of increasing the sensitivity of a camera's image sensor. It is effectively analogous to using high speed film in film camera. When a digital camera takes a photo in low light, it will often increase the sensitivity of its sensor array to obtain a properly exposed photograph. While it is an effective process, the sensor will often pickup bunk or irregular data and the resulting photograph will have 'noise'. This is especially apparent in the darkest areas of the photograph, where one will see coloured sparkles rather than solid black. It's very common to see these visually unpleasant irregularities on cell phone cameras in low light.
Often grain and image noise are unavoidable, especially if you need to shoot a digital camera in low light or use high speed film.
So is grain a bad thing? Well, I've always felt technical quality comes second to style... so it's really a personal preference. Does grain add to or take away from a picture? Is the picture more stylish with or without grain? Often times I personally find grain to have a certain charm, and enhance the picture. Yet other times, I find the grain distracting and feel it takes away from the picture. It's up to the photographer to weigh on these questions, then select an appropriate ISO whether film or digital.
Click on the left or right side of the full sized image to jump back and forth between the two.
When travelling Europe in 2011, all the cameras with me were film. With cost being an issue, much of the film shot abroad was Lomographic. Lomo film is cheap and fun, but not of the highest technical quality. I've always described it as "high in style, yet low in quality." Above is an example of Lomography Redscale XR 50-200. The image as scanned is on the left. Even though not a high speed film, the image is quite grainy. With a few simple click in Adobe Lightroom, one can do quite an amount of grain reduction, as seen on the right. The grain reduction has made the image much cleaner and smoother, yet it has compromised some of the fine detail and style.
Which photograph is better? Well, that's up to you! I think they're both pretty sweet.