Have you ever wondered how Youtubers make such epic trailer videos for their Minecraft gameplay? The short answer to this question is that they use a mod. There are a large number of these types of mods for Minecraft 1.7 and 1.8, but most of those haven't been updated to version 1.9 yet. Fortunately, there is BauerCam by diapenger to fill the void and allow for smooth, cinematic videos in 1.9 that look like they have been professionally produced.
Videos are made by setting a series of points for the cam to follow. Points are added by pressing the 'p' key in game, and there must be at least two points set before you can start the cinematic view. You can review the points that you set by using /cam goto followed by the point number and can also replace specific points or clear the points. When setting points, keep in mind that they are added in chronological order. In addition to your position, the direction that you are looking when the point is set will be reflected in the video. You can tilt the camera axis left or right using the 'j' and 'l' keys and even completely invert your view.
Whenever your points are set and you are ready to see the result, type /cam start followed by the number of frames to use while traveling between points. For a rapid movement you can use fewer frames, but for the slow, dramatic, smooth panning that creates the most impressive effect, you will need to choose a larger frame number. The actual frame number that you will use depends on the desired speed, the number of points that you set, the distance between the points, and the desired length of the clip. In tests, 1000 frames is a good place to start and you can adjust as necessary if it feels too slow or fast.
I know I'll start using BauerCam for any videos that I make in the future. It is a powerful and intuitive modification that allows for professional cinematic shots in all of your new Minecraft 1.9 maps. In literally seconds, you can set up and execute the slow panning shot that you have always seen in youtube videos but could never recreate. It is time to take your video production game to the next level!