I used a 50mm prime lens at f1.8 to create this image. I wanted the fence to be in focus and the trees out of focus as much as possible.
This is a prime example that you can take great images with relatively inexpensive lenses. The Canon 50mm f1.8 lens used to cost only around $50.00 a few years ago. Now you can be lucky if you get it for about $100.00. This lens is very sharp and you can create great images with it. The great French photographer Henri Cartier-Bresson used a 50mm lens in almost all of his photographs!
Enjoy and happy photographing!