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 Samyang 300mm f6.3 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 Samyang 300mm f6.3 with a length of 74mm, is 50mm shorter. Besides being longer, the Tamron 18-400mm F3.5-6.3 VC also has a larger diameter of 79mm compared to the Samyang 300mm f6.3's 65mm 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. Samyang 300mm f6.3 weighs 260g, 63% (450g) lighter than the Tamron 18-400mm F3.5-6.3 VC's weight of 710g.
Filter Threads
The Tamron 18-400mm F3.5-6.3 VC has a filter size of 72mm whereas the Samyang 300mm f6.3 has a 26mm 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 26mm filters that we recommend for the Samyang 300mm f6.3:
Lens Mounts
Both the Tamron 18-400mm F3.5-6.3 VC and the Samyang 300mm f6.3 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 the Canon EF-S mount.
Samyang 300mm f6.3 is also available in Canon EF , Four Thirds 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 Samyang 300mm f6.3 is a prime lens with fixed focal lenght of 300mm which has an effective (full-frame 35mm equivalent) focal range of 450mm when used on a APS-C / DX format camera.
