之前在外媒上看过资料,大概意思是这类高速镜头是为以前大画幅X光机拍片设计的。由于当时大画幅X胶片感光度极低,所以必须极大的光圈优先保证曝光,分辨率等参数为其次,历史上Rodenstock、徕卡加拿大、Kowa和荷兰De Oude Delft等都有过类似产品。
而这枚Canon XI 50mm 1:0.75 是佳能上世纪70年代为美国PICKER公司设计制造的用于X光设备曝光用的。
关于美国PICKER Corp.的资料:
Picker, an X-ray equipment specialist was founded by James Picker in New York City in 1915, offering sales and service of X-ray equipment, film and accessories. The James Picker company was acquired by a financial services company, CIT Financial, in 1958. In 1967, the company changed its name from Picker X-ray to Picker Corporation. In the same year Picker acquired Dunlee Corporation, a company in Chicago founded by Dunmore Dunk and Zed Atlee to meet demand for quality X-ray tubes and special purpose tubes. Picker was an important innovator in the nuclear and ultrasonic imaging fields during the 1960s, being the first of the major American x-ray equipment producers to enter the new product areas. Although members of the Picker family continued to manage the medical equipment subsidiary, the senior members were reaching retirement age during the mid-1970s.
During the 1960s and 1970s, the number of imaging equipment manufacturers further grew. By the mid-1970s, the U.S. market alone was being served by more than 100 manufacturers. In the U.S., the leaders remained the same, with General Electric, Picker, Philips, Siemens, and the Westinghouse system controlling about 70% of the American radiology market in the mid-1970s.
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Picker,X光设备专业公司,由詹姆斯.匹克于1915年在纽约创建,提供X光设备销售及服务、胶片、附件等。詹姆斯.匹克公司由于1958年获得了金融公司资助,于是公司在1967年由匹克X光更名为匹克公司,同年.......吧啦吧啦(偏题话题懒得翻了)