So to show the difference these toys make, I have uploaded a few shots using nothing, the screw on and the extension tubes.
The first two are taken with the 18-105mmvr nikon lens. The second shot just being a crop of another shot.


The second two were taken with the same lens and the screw on attachments.


The last two with the extension tubes. With the extension tubes, you have to have the camera fully in Manual mode as the camera can meter on anything.


None of these are particularly wonderful, so I don't think I will even add any to flickr, but just wanted to show you how I am getting on.