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 VC LD and the Tamron AF 18-270mm f3.5-6.3 II VC LD 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 AF 18-270mm f3.5-6.3 II VC LD is the longer of the two lenses at 101mm. The Tamron 17-50mm f2.8 XR II VC LD with a length of 95mm, is 6mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 80mm.
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 AF 18-270mm f3.5-6.3 II VC LD weighs 560g, 1% (10g) lighter than the Tamron 17-50mm f2.8 XR II VC LD's weight of 570g.
Filter Threads
Both the Tamron 17-50mm f2.8 XR II VC LD and the Tamron AF 18-270mm f3.5-6.3 II VC LD 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
The Tamron 17-50mm f2.8 XR II VC LD has the Canon EF lens mount whereas the Tamron AF 18-270mm f3.5-6.3 II VC LD has the Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with these mounts are Canon T8i, Canon 90D and Canon SL3 for the Canon EF Mount and Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount.
Tamron 17-50mm f2.8 XR II VC LD is also available in the Nikon F (DX) mount.
Tamron AF 18-270mm f3.5-6.3 II VC LD is also available in Canon EF mount.
Focal Range
Tamron 17-50mm f2.8 XR II VC LD has a focal range of 17-50mm and
2.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
27.2-80mm when used on a APS-C / DX format camera.
On the other hand, the Tamron AF 18-270mm f3.5-6.3 II VC LD has a focal range of 18-270mm and 15.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-405mm when used on a APS-C / DX format camera.
