Yes, at 1.8 it does not produce the same quality as canon 50 / 1.4 or any sigma. Because the lenses are of different price ranges, but in its class, for its price, it is really handsome and deserves to be in the bags of all canon owners Examples:
Nikon 50mm f/1.8D Lens: Perfect for Nikon DSLR Cameras!
97 Review
Canon EF 40mm f/2.8 STM Lens - Fixed Black (6310B002) for US Cameras
76 Review
π· Nikon AF-S NIKKOR 50mm f/1.4G Lens with Auto Focus: Perfect for Nikon DSLR Cameras
76 Review
Nikon 35mm f/1.8G Auto Focus Lens for Nikon DSLR Cameras - Black (Model 2183)
125 Review