D4S because that's acceptable only for seasoned photographers who create their dwelling from pressing photos. Based on how black the background is (darker typically = better) it's likely you have to dialin some exposure compensation to truly get your bokeh to essentially pop. Next, try placing a topic how to blur background with a kit lens of some type before the camera at the minimum target distance (or there about) together with the bokeh shows inside the history. It will take a small experimenting with subject material and light (both foreground and background) in almost no time you need to be capturing bokeh like an expert!
For the amateur, the aperture will be the starting while in the contact that handles light's quantity which makes it through the contact and shutter for the video/alarm. Fast lenses below f/2.8 like my 20 year old manual focus Pentax-A 50mm f/1.7 SMC are well suited for filming bokeh (and it is the lens I take advantage of for some of my bokeh shots on Fickr). I've discovered that the smaller the emphasis distance towards the forefront topic, the higher the background bokeh I'll get.
Depending on how dark the background is (deeper typically = better) you might have to dial in some exposure payment to get your bokeh to really place. Next, try getting a topic of some sort in front of the camera at least concentration distance (or there about) using the bokeh highlights in the history. It will have a minor experimenting with subject matter and illumination (both forefront and history) but in almost no time you need to be capturing bokeh like a pro!