DOF or Depth of Field.
WhatWhat is with all the blurry stuff?
Wikipedia says : In optics, particularly as it relates to film and photography, depth of field (DOF), also called focus range or effective focus range, is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image. Although a lens can precisely focus at only one distance at a time, the decrease in sharpness is gradual on each side of the focused distance, so that within the DOF, the unsharpness is imperceptible under normal viewing conditions.
So ... what does that mean in reality ... when I'm talking to people about cameras, I like to mention those 'lovely' portrait shots, where a lot of the background is out of focus ...
When lots of the image is 'not in focus' this as known as a shallow depth of field (this is what I like).
I tend to use the effect in my landscapes (as wellas in portraits) but it's the people images that are more generally understood, so it's the best way to demonstrate!
Depth of field is altered by messing about with the aperture on your lens ... bigger the aperture, the shallower the depth of field (the more out of focus parts of the image are).
I'm planning on eventually adding some basic tutorials to my website, to give people an idea of how to achieve these kinds of results themselves!
But in the meantime here is a nice slideshow of how the basic principle works :)
I actually tried to shoot some nice outdoor images for the slideshow, but I didn't have my tripod and I'm always telling people the best way to experiment using aperture is to find something around the house ... line up some mugs, or use a line of potted plants in the garden ... then I spotted the knobs on my stupidly large oven ... perfect to show the basics.
I can see all obstacles in my way
Gone are the dark clouds that had me blind
Johnny Nash - I Can See Clearly Now Listen Now!