Grain or Noise?
Grain is a term usually used in film photography and is used to describe distortion or dot like appearance in pictures when using high ISO film in low light conditions. Digital photography refers to the similar appearance in its' pictures as noise. Be that as it may, I still refer to it as grain, a habit left over from my film days. Although grain and noise are completely different things, analogue and digital, I like to call my noise grain.
I usually use a high megapixel Nikon D800 for all my work but if not working and I want to travel light i take my D90. The camera is smaller and a lot lighter but the downside is the smaller sensor and lower megapixel count. This means at low light I should crank up the ISO to get a shutter speed I can reasonably handhold which can lead to blurred, out of focus shots sometimes, but will certainly introduce noise, or grain, into the picture. However, as my maxim number one is that it doesn't have to always be in focus and number two is that not all grain is bad, it's better to get this than no picture at all!
The picture here was taken in Penzance on New Year's Eve using a D90 and 50mm 1.8 lens and is a good example of grain, noise. My reason for using this set up was that it was New Year's Eve, I did not know what was going to happen, it's an old camera already bashed so I couldn't make it much worse and finally, if I left it somewhere it wouldn't hurt as much as if I had left my other camera behind. The camera fits into a huge pocket on the inside of my coat so it's easy to carry around.
Now this picture looks awful in colour, the grain just washes it out, it looks a bit weak. But, convert to black and white, darken some of the blacks even further and the grain gives it a noir feel. The halo from the streetlight shows grain as it bleeds into the shadows and the cobbles stand out just enough with highlights showing the way. The huge shadow, accentuated by the slope of the street, adds just a bit of menace to the picture.
For more examples of grain/noise in pictures have a look at a couple of additions to the People Gallery under Projects here