Does anyone know what the minimum focusing distance is? Yep! All types of lenses have an MFD, which is the minimum focusing distance from the camera sensor to the photo object. If it is closer than that distance, the object will become blurry. Usually MFD is expressed in length such as 0.5m.
Source: http://belfot.com
In the image above, the MFD is 0.25 m (25 cm), meaning the minimum distance from the camera sensor to the object to keep it sharp is 25 cm, if it is less than 25 cm then the photo will be blurry.
Usually this MFD gets a lot of attention from macro photographers. For macro lenses, the MFD can reach 16 cm. So, don't be surprised if a macro lens can photograph objects from a very close distance, and still be able to focus.