The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 17-50mm f2.8 XR II LD and the Nikon 18-70mm f3.5-4.5G ED-IF 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 17-50mm f2.8 XR II LD is the longer of the two lenses at 82mm. The Nikon 18-70mm f3.5-4.5G ED-IF with a length of 76mm, is 6mm shorter. Besides being longer, the Tamron 17-50mm f2.8 XR II LD also has a larger diameter of 74mm compared to the Nikon 18-70mm f3.5-4.5G ED-IF's 73mm 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 18-70mm f3.5-4.5G ED-IF weighs 420g, 2% (10g) lighter than the Tamron 17-50mm f2.8 XR II LD's weight of 430g.
Below you can find the dimension and weight table of the Standard Zoom Lenses in Nikon F (DX) Mount for size comparison purposes.
Standard Lenses in Nikon F (DX) Mount for Size Comparison
Filter Threads
Both the Tamron 17-50mm f2.8 XR II LD and the Nikon 18-70mm f3.5-4.5G ED-IF 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 17-50mm f2.8 XR II LD and the Nikon 18-70mm f3.5-4.5G ED-IF 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 17-50mm f2.8 XR II LD is also available in the Canon EF , Sony Alpha and Pentax KAF mounts.
Focal Range
Tamron 17-50mm f2.8 XR II LD has a focal range of 17-50mm and
2.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
25.5-75mm when used on a APS-C / DX format camera.
On the other hand, the Nikon 18-70mm f3.5-4.5G ED-IF has a focal range of 18-70mm and 3.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-105mm when used on a APS-C / DX format camera.
