The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 17-40mm f1.8 and the Sigma 18-50mm F2.8 DC DN C RF 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. Sigma 17-40mm f1.8 is the longer of the two lenses at 116mm. The Sigma 18-50mm F2.8 DC DN C RF with a length of 75mm, is 41mm shorter. Besides being longer, the Sigma 17-40mm f1.8 also has a larger diameter of 73mm compared to the Sigma 18-50mm F2.8 DC DN C RF's 69mm diameter.
Below you can find a scaled side-by-side image of Sigma 17-40mm f1.8 and Sigma 18-50mm F2.8 DC DN C RF to get a better idea of how their sizes compare in real life.
Comparison image of the Sigma 17-40mm f1.8 and the Sigma 18-50mm F2.8 DC DN C RF 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. Sigma 18-50mm F2.8 DC DN C RF weighs 300g, 43% (235g) lighter than the Sigma 17-40mm f1.8's weight of 535g.
Filter Threads
The Sigma 17-40mm f1.8 has a filter size of 67mm whereas the Sigma 18-50mm F2.8 DC DN C RF has a 55mm 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 Sigma 17-40mm f1.8:
And these are the 55mm filters that we recommend for the Sigma 18-50mm F2.8 DC DN C RF:
Lens Mounts
The Sigma 17-40mm f1.8 has the Sony E lens mount whereas the Sigma 18-50mm F2.8 DC DN C RF has the Canon RF lens mount . Some of the latest released cameras that are compatible with these mounts are Sony ZV-E10 II , Sony A6700 and Sony FX30 for the Sony E Mount and Canon R50 V , Canon R100 and Canon R50 for the Canon RF Mount.
Leica L , Fujifilm X and Canon RF mounts.
Focal Range
Sigma 17-40mm f1.8 has a focal range of 17-40mm and
2.4X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
25.5-60mm when used on a APS-C / DX format camera.
On the other hand, the Sigma 18-50mm F2.8 DC DN C RF has a focal range of 18-50mm and 2.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 28.8-80mm when used on a APS-C / DX format camera.
