Originally posted by ducdao Great tips! Another option is simply use Photoshop to create that boked blur
Every example of that that I've seen looks very fake. It's much better to shoot properly in the style one is going for.
@OP, you don't need a really fast lens, if you can set up your shot how you want. A fast lens will be more versatile though, and they're often a better quality. Have the subject very close to the lens with a more distant background, and you can get good subject isolation even at f./8 or smaller.
This I took at f./11 with my 70-300mm Sigma zoom (a cheapie). It would have been better with an extra bit of DoF on the subject, but it gets the point across that smaller apertures can work for this. The dragonfly was at the minimum focusing distance of the lens, or very close to it. The background is made up of yellow flowers and various weeds, perhaps 20 feet away.