Sigma: Lens Testing by Marco Brugnoli
Sigma lenses are well known for their quality in terms of detail and sharpness. I could have saved by choosing less high-performing lenses, but I would not have achieved the same results.
When I opened the boxes, I was struck by how lightweight these lenses are—so much so that I initially had some doubts about their performance. Until now, I had never used a lens weighing less than 300 grams. However, their performance proved to be outstanding.

The Sigma 10–18mm delivers a rather “cool” rendering with limited contrast, while the 18–50mm offers higher contrast. In post-production, these characteristics can be easily corrected.
At f/2.8, vignetting is quite pronounced, particularly noticeable when using an ND filter; however, simply removing the filter and stopping down to f/8 resolves the issue.

I found the highest level of sharpness between f/7.1 and f/8, with less diffraction on the 10–18mm and more noticeable diffraction on the 18–50mm. Even in this case, post-production adjustments can be applied.
Sharpness and detail quality help to extract the maximum potential from the image.

I greatly appreciated Sigma lenses—without them, I would not have been able to achieve this quality.