Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Tamron 70-300mm f4-5.6 VC USD is the longer of the two lenses at 143mm. The Nikon AF-P DX 70-300mm F4.5-6.3G with a length of 125mm is 18mm shorter. Besides being longer, the Tamron 70-300mm f4-5.6 VC USD also has a larger diameter of 82mm compared to Nikon AF-P DX 70-300mm F4.5-6.3G's 72mm diameter.
Weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Nikon AF-P DX 70-300mm F4.5-6.3G weighs 400g, which means it is 365g (91%) lighter than the Tamron 70-300mm f4-5.6 VC USD which has a weight of 765g.
Lens Mounts
Both Nikon AF-P DX 70-300mm F4.5-6.3G has the Nikon F (DX) lens mount whereas the Tamron 70-300mm f4-5.6 VC USD has the Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount and Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount.
Tamron 70-300mm f4-5.6 VC USD is also available in Canon EF mount.
Focal Range