The 70-200mm telephoto lens *, whether from Canon, Sony or Nikon, is the most common telephoto lens focal length. It is a zoom lens that allows you to cover a range from 70mm to 200mm and bring distant objects closer.
Ben's telephoto lens has a maximum aperture of 4.0 and an image stabilizer, which helps him avoid camera shake when filming and taking photos, especially at long focal lengths. The 70-200mm is also good for portrait photos, as it can isolate the subject nicely from the background (if the aperture is set correctly).
In certain situations you can also take landscape photos with a telephoto lens. In this video Ben gives you tips on how to do this.