At present, the brands that produce SLR can be counted with your fingers. Japan has Nikon, Pentax Ricoh and Canon. These three brands are the most famous because they are cheap. There are Leica, Luleffler and Lin Hafu. Compared with other European brands, Leica is relatively cheap and well-known, while Lin Hafu has been a small workshop-style enterprise from the very beginning, with little popularity. Lu Laifu is a large-format film machine, and it is too expensive, so it is not popular outside the professional field; There are two brands in Switzerland, Alpa and Sinna. Alpa is the most luxurious hand-made film camera in the world, and you can buy a Leica camera for each accessory. Now Sinna rarely leaves the camera body and concentrates on making the digital back of the medium format camera. There is a Hasselblad in Sweden who makes a medium format camera. This camera is almost perfect, but the disadvantage is that it is too expensive. Another one is Freescale in Denmark, which is also very expensive. Freescale in Europe, Hasselblad and Pentax in Japan are the most famous in the field of medium format cameras. Some famous Japanese brands, such as Panasonic, Fuji, Olympus, etc. Instead of doing a SLR, I switched to a single camera. Sony did a SLR for a while after acquiring the old optical Minolta, because the market share problem was not done; Ricoh acquired the famous Pentax before setting foot in digital SLR.