The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron 85mm F1.8 VC and the Tamron 90mm F2.8 VC USD Macro 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 90mm F2.8 VC USD Macro is the longer of the two lenses at 115mm. The Tamron 85mm F1.8 VC with a length of 91mm, is 24mm shorter. On the other hand, the Tamron 85mm F1.8 VC has a larger diameter of 85mm compared to the Tamron 90mm F2.8 VC USD Macro's 76mm 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. Tamron 90mm F2.8 VC USD Macro weighs 550g, 21% (150g) lighter than the Tamron 85mm F1.8 VC's weight of 700g.
Filter Threads
The Tamron 85mm F1.8 VC has a filter size of 67mm whereas the Tamron 90mm F2.8 VC USD Macro has a 58mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Tamron 85mm F1.8 VC:
And these are the 58mm filters that we recommend for the Tamron 90mm F2.8 VC USD Macro:
Lens Mounts
Both the Tamron 85mm F1.8 VC and the Tamron 90mm F2.8 VC USD Macro has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Tamron 85mm F1.8 VC is also available in Sony Alpha and Nikon F (FX) mounts.
Tamron 90mm F2.8 VC USD Macro is also available in Nikon F (FX) and Sony Alpha mounts.
Focal Range
Tamron 85mm F1.8 VC is a prime lens with fixed focal lenght of 85mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
136mm.
On the other hand, the Tamron 90mm F2.8 VC USD Macro is a prime lens with fixed focal lenght of 90mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 144mm.