The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 70-300 F4.5-6.3 Di III and the Tamron 18-300mm F3.5-6.3 Di 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 70-300 F4.5-6.3 Di III is the longer of the two lenses at 148mm. The Tamron 18-300mm F3.5-6.3 Di with a length of 126mm, is 22mm shorter. Besides being longer, the Tamron 70-300 F4.5-6.3 Di III also has a larger diameter of 77mm compared to the Tamron 18-300mm F3.5-6.3 Di's 76mm diameter.
Below you can find a scaled side-by-side image of Tamron 70-300 F4.5-6.3 Di III and Tamron 18-300mm F3.5-6.3 Di to get a better idea of how their sizes compare in real life.
Comparison image of the Tamron 70-300 F4.5-6.3 Di III and the Tamron 18-300mm F3.5-6.3 Di Size and Weight 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 70-300 F4.5-6.3 Di III weighs 545g, which means it is 75g (12%) lighter than the Tamron 18-300mm F3.5-6.3 Di which has a weight of 620g.
Filter Threads
Both the Tamron 70-300 F4.5-6.3 Di III and the Tamron 18-300mm F3.5-6.3 Di have the same Filter thread size of 67mm .
Below are links to the 67mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Tamron 70-300 F4.5-6.3 Di III and the Tamron 18-300mm F3.5-6.3 Di has the same Sony E lens mount . Some of the latest released cameras that are compatible with the Sony E lenses are Sony FX5 , Sony A7R VI and Sony A7 V .
Fujifilm X mount.
Focal Range
Tamron 70-300 F4.5-6.3 Di III has a focal range of 70-300mm and
4.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
105 - 450mm .
On the other hand, the Tamron 18-300mm F3.5-6.3 Di has a focal range of 18-300mm and 16.7X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-450mm when used on a APS-C / DX format camera.
