Why is the lens of a SLR camera called a dog's head and a cow's head? What is the difference? What is the head of 50mmf 1.8G?

In fact, the dog's head and the cow's head are used to distinguish the different quality of the lens. For example, we often say that this man is great, he is great, and so is the camera. In contrast, the picture quality is very "dog" and the dog head is very bad.

Some lenses are of good quality and workmanship and will be recognized as bull's heads, such as 70-200/2.8, 300/2.8 telephoto, etc. Mainly judging the quality of a shot can often be distinguished from the market price. Expensive lens materials are advanced, the lens group structure is more perfect, the aperture is larger, and the picture quality is naturally better. However, there is no absolute strict standard for bull's head and dog's head.

Take the 50/ 1.8G in your hand, its picture quality is obviously different from that of 18-55, 18- 105, and it can barely become a bull's head. But it has 50/ 1.4G, the lens group is more perfect, the aperture is larger, and the positioning price is more than 3,000 yuan. At present, it is 50/ 1.4, which is less than half of its price. It is obviously a dog's head.

However, there is also a saying that the bull's head and the dog's head are not talking about the head in front of the fuselage, but the head behind the fuselage. Equipment is not the only criterion for determining image quality. In the face of limited equipment, we should give full play to the characteristics of equipment with our own technology and win with technology and connotation. That's real kung fu, a real bull's head.