The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 12mm f1.4 and the Sigma 18-50mm F2.8 DC DN C 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 18-50mm F2.8 DC DN C is the longer of the two lenses at 75mm. The Sigma 12mm f1.4 with a length of 70mm, is 5mm shorter. On the other hand, the Sigma 12mm f1.4 has a larger diameter of 68mm compared to the Sigma 18-50mm F2.8 DC DN C's 65mm 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. Sigma 12mm f1.4 weighs 235g, which means it is 55g (18%) lighter than the Sigma 18-50mm F2.8 DC DN C which has a weight of 290g.
Filter Threads
The Sigma 12mm f1.4 has a filter size of 62mm whereas the Sigma 18-50mm F2.8 DC DN C 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 62mm filters that we recommend you to consider for the Sigma 12mm f1.4:
And these are the 55mm filters that we recommend for the Sigma 18-50mm F2.8 DC DN C:
Lens Mounts
The Sigma 12mm f1.4 has the Fujifilm X lens mount whereas the Sigma 18-50mm F2.8 DC DN C has the Leica L lens mount. Some of the latest released cameras that are compatible with these mounts are Fujifilm X-T30 III, Fujifilm X-E5 and Fujifilm X-M5 for the Fujifilm X Mount and Leica TL2, Leica TL and Leica T Typ 701 for the Leica L Mount.
Sigma 12mm f1.4 is also available in the Sony E and Canon RF mounts.
Sigma 18-50mm F2.8 DC DN C is also available in Sony E and Fujifilm X mounts.
Focal Range
Sigma 12mm f1.4 is a prime lens with fixed focal lenght of 12mm which has an effective (full-frame 35mm equivalent) focal range of
18mm when used on a APS-C / DX format camera.
On the other hand, the Sigma 18-50mm F2.8 DC DN C has a focal range of 18-50mm and 2.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-75mm when used on a APS-C / DX format camera.
