The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Yongnuo 50mm F1.8S II and the Tamron 20-40mm F2.8 VXD 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 20-40mm F2.8 VXD is the longer of the two lenses at 86mm. The Yongnuo 50mm F1.8S II with a length of 58mm, is 28mm shorter. Besides being longer, the Tamron 20-40mm F2.8 VXD also has a larger diameter of 74mm compared to the Yongnuo 50mm F1.8S II's 64mm 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. Yongnuo 50mm F1.8S II weighs 134g, which means it is 231g (63%) lighter than the Tamron 20-40mm F2.8 VXD which has a weight of 365g.
Filter Threads
The Yongnuo 50mm F1.8S II has a filter size of 49mm whereas the Tamron 20-40mm F2.8 VXD has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 49mm filters that we recommend you to consider for the Yongnuo 50mm F1.8S II:
And these are the 67mm filters that we recommend for the Tamron 20-40mm F2.8 VXD:
Lens Mounts
Both the Yongnuo 50mm F1.8S II and the Tamron 20-40mm F2.8 VXD has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony ZV-E10 II, Sony A6700 and Sony FX30.
Focal Range
Yongnuo 50mm F1.8S II is a prime lens with fixed focal lenght of 50mm which has an effective (full-frame 35mm equivalent) focal range of
75mm when used on a APS-C / DX format camera.
On the other hand, the Tamron 20-40mm F2.8 VXD has a focal range of 20-40mm and 2.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 30 - 60mm.
