What to look for...
Here are a few things to bear in mind when choosing a superzoom
All of the lenses on test offer an 18mm minimum focal length, which is equivalent to 27mm, apart from the Tamron 16-300mm lens, which is equivalent to 24mm. Focus distance scale Most lenses on test have a focus distance scale printed on the focus ring or beneath a viewing panel, but the Tamron 18-200mm and the newer edition of the Nikon 18-300mm have none at all.
The usual choice of maximum telephoto focal length is either 200mm or 300mm – equivalent to 300mm or 450mm respectively, in full-frame terms. The Tamron 18-270mm lens is the exception.
Ring-type ultrasonic autofocus is the most refined option, although electric or ultrasonic motor-driven systems can help reduce the size and weight of the lens.
Apart from the Tamron 18-200mm, which has a plastic mounting plate, all of the other lenses on test have a metal mount.
A weather-seal ring is fitted to the mounting plates of all three Nikon lenses, and to the Tamron 18-200mm and 16-300mm lenses.