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 Nikon 18-200mm f3.5-5.6G IF-ED VR 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 Nikon 18-200mm f3.5-5.6G IF-ED VR with a length of 97mm, is 27mm shorter. Besides being longer, the Tamron 18-400mm F3.5-6.3 VC also has a larger diameter of 79mm compared to the Nikon 18-200mm f3.5-5.6G IF-ED VR's 77mm 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. Nikon 18-200mm f3.5-5.6G IF-ED VR weighs 560g, 21% (150g) lighter than the Tamron 18-400mm F3.5-6.3 VC's weight of 710g.
Filter Threads
Both the Tamron 18-400mm F3.5-6.3 VC and the Nikon 18-200mm f3.5-5.6G IF-ED VR have the same Filter thread size of 72mm.
Below are links to the 72mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Tamron 18-400mm F3.5-6.3 VC and the Nikon 18-200mm f3.5-5.6G IF-ED VR 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.
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 Nikon 18-200mm f3.5-5.6G IF-ED VR has a focal range of 18-200mm and 11.1X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-300mm when used on a APS-C / DX format camera.