The SIGMA 50mm F1.4 EX DG is a single-focal-length lens with a fast F1.4 aperture and excellent descriptive power. - Brand: SIGMA - Model Name: 50mm F1.4 EX DG - Accessories: Case, Instruction Manual - Filter Diameter: 77mm - Lens Type: Single-focal-length lens I haven't used it much since I bought it, but it's an old item, so there's some dust. It has almost no signs of use. It was used for normal photography. There is some dust and debris, but the images are fine. This is for people who use it frequently. Please look elsewhere if you are particular about details. I don't know much about technical things, but I will answer to the best of my ability. If there are any parts you are concerned about, I will upload photos, so please feel free to ask. It was a single-focal-length lens that was talked about at the time as being sharper than the Canon genuine 50mm 1.4. Zoom lenses are definitely more convenient, but for some reason, taking pictures with a 50mm single-focal-length lens is cool, which is a bit unclear, but please capture the image as you see it with the 50mm, which is the range of human vision. I mainly used an 85mm single-focal-length lens, so I rarely used this product.