One item we have been keeping an eye on is the Tamron 100-400mm F/4.5-6.3 VS USD Telephoto lens for Canon DSLR cameras. This lens is perfect for shooting sports, wildlife, and astrophotography ...

Although relatively lightweight for an f/2.8 constant-aperture telephoto zoom, the Tamron feels solid and robust. Convincing build quality is backed up by a set of weather-seals and a fluorine coating ...

Tamron stretched things a bit with its Tamron ... This Sigma lens goes more properly into telephoto territory, stretching to 105mm instead of 75mm, but is almost twice as heavy.