When I was aching for the 300mm lens, it was not only for the smooth backgrounds but also for the smooth foregrounds. An experienced photographer can quickly pick the subjects and backgrounds. I can pick them, slowly. But then you have this thing about foreground, and now suddenly you have three things to worry about: subject, background, and foreground. What makes the foreground such a complicated affair is two things – too close. That is (besides an unintentional phonetic pun) the foreground is too close to the subject, or it’s too close to the camera. Too close the subject, and the foreground will show as distracting detail. Too close to the camera, and the foreground either obstructs the whole subject, and then when you lift the camera to get a clear view of the subject, the foreground fade is so subtle that you hardly notice it at the bottom of the frame. And let’s not even start talking about the colours, highlights and shadows… you’ll find that the background is indeed a breeze to sort out, but the foreground will give you a headache every time. I’ve had the 300mm lens for 2 years now, and I don’t have a single picture which I would specifically remember for it’s awesome foreground.
Sometimes, just sometimes, you get lucky and you’ll find something that you can use to frame your subject. I was lucky.