The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 18-400mm F3.5-6.3 VC and the Tamron 16-300mm f3.5-6.3 II VC PZD for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Tamron 18-400mm F3.5-6.3 VC is the longer of the two lenses at 124mm. The Tamron 16-300mm f3.5-6.3 II VC PZD with a length of 100mm, is 24mm shorter. Besides being longer, the Tamron 18-400mm F3.5-6.3 VC also has a larger diameter of 79mm compared to the Tamron 16-300mm f3.5-6.3 II VC PZD's 75mm diameter.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Tamron 16-300mm f3.5-6.3 II VC PZD weighs 540g, 23% (170g) lighter than the Tamron 18-400mm F3.5-6.3 VC's weight of 710g.
Below you can find the dimension and weight table of the SuperZoom Lenses in Nikon F (DX) Mount for size comparison purposes.
Super Telephoto Lenses in Nikon F (DX) Mount for Size Comparison
Filter Threads
The Tamron 18-400mm F3.5-6.3 VC has a filter size of 72mm whereas the Tamron 16-300mm f3.5-6.3 II VC PZD has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 72mm filters that we recommend you to consider for the Tamron 18-400mm F3.5-6.3 VC:
And these are the 67mm filters that we recommend for the Tamron 16-300mm f3.5-6.3 II VC PZD:
Lens Mounts
Both the Tamron 18-400mm F3.5-6.3 VC and the Tamron 16-300mm f3.5-6.3 II VC PZD has the same Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with the Nikon F (DX) lenses are Nikon D3500, Nikon D7500 and Nikon D5600.
Tamron 18-400mm F3.5-6.3 VC is also available in Canon EF-S mount.
Tamron 16-300mm f3.5-6.3 II VC PZD is also available in Canon EF and Sony Alpha mounts.
Focal Range
Tamron 18-400mm F3.5-6.3 VC has a focal range of 18-400mm and
22.2X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
27-600mm when used on a APS-C / DX format camera.
On the other hand, the Tamron 16-300mm f3.5-6.3 II VC PZD has a focal range of 16-300mm and 18.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 24-450mm when used on a APS-C / DX format camera.