In what is a typical move for me, I have ignored an important issue in my rush to move onto the next big thing. Before I go any further, I must rectify this and talk about aperture.
Aperture refers to the little contraption in the camera that looks like an iris (in the eyeball, not the garden). Open wide means lots of light gets in, and closed up means little.
The really annoying thing is that the numbers on the camera are the opposite way around. Eg aperture F8 is almost closed, and F2.8 floods the light in. Can't believe I have been doing this course for 4 weeks and I still always turn the dial the wrong way.
But this is a multi-tasking function, and not only does it have an impact on light level, but also the depth of field. In terms that simpletons like me can understand, it's like the camera puts different sets of specs on. (Broadly defined) Low aperture means that it is looking at something close, and anything in the distance will be blurred. High aperture means it has it's short-sighted specs on, and is finding a more distant subject, so objects in the background are more prominent.
And it gets better - the depth is not the only affected dimension. Low aperture may also create blur at the edges, even if the subject is close - so the width is also effected. Check out these (boring) photos. They go from low to high as we go down - so ironically (and topically) they are positioned inversely. You might notice, if you have your specs on, that the background becomes more prominent in the right one (which has an aperture of F8.0)
Lesson learned? Portraits must be taken with low aperture. Group photos with high. Also, aperture is a really complicated sounding term, so it's a good way to impress (or bore) all your non-photographicalised friends. For the rest of it I'm still fiddling around, stay tuned.