The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Nikon Z 50-250mm F4.5-6.3 VR and the Tamron 18-400mm F3.5-6.3 VC 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 Z 50-250mm F4.5-6.3 VR with a length of 110mm, is 14mm shorter. Besides being longer, the Tamron 18-400mm F3.5-6.3 VC also has a larger diameter of 79mm compared to the Nikon Z 50-250mm F4.5-6.3 VR's 74mm 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 Z 50-250mm F4.5-6.3 VR weighs 405g, which means it is 305g (42%) lighter than the Tamron 18-400mm F3.5-6.3 VC which has a weight of 710g.
Filter Threads
The Nikon Z 50-250mm F4.5-6.3 VR has a filter size of 62mm whereas the Tamron 18-400mm F3.5-6.3 VC has a 72mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 62mm filters that we recommend you to consider for the Nikon Z 50-250mm F4.5-6.3 VR:
And these are the 72mm filters that we recommend for the Tamron 18-400mm F3.5-6.3 VC:
Lens Mounts
The Nikon Z 50-250mm F4.5-6.3 VR has the Nikon Z lens mount whereas the Tamron 18-400mm F3.5-6.3 VC has the Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon Z30, Nikon Z fc and Nikon Z50 for the Nikon Z Mount and Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount.
Tamron 18-400mm F3.5-6.3 VC is also available in Canon EF-S mount.
Focal Range
Nikon Z 50-250mm F4.5-6.3 VR has a focal range of 50-250mm and
5.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
75-375mm when used on a APS-C / DX format camera.
On the other hand, the 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.