The camera was revolutionary for the time with its modular design that allowed exchanging lenses, viewfinders and film magazines. The shutter was made of thin stainless steel which was light and durable enough to withstand the high acceleration forces of this fast shutter. The 1600F cameras did show a couple of problems (especially the first series) so a number of changes were introduced during the production period that lasted from 1949–1953. The 1600F was initially released with the Kodak Ektar 2.8/80 mm and the Ektar 3.5/135 mm lenses. Only prototypes were made of the Ektar 6.3/55 mm and the 5.6/254 mm lenses. The successor of the 1600F was the 1000F (1953–1957). The 1000F was named after its reduced shortest shutter speed of 1/1000 s. The 1000F has a different shutter mechanism and proved to be more reliable and robust than its predecessor. During production of the 1600F, Carl Zeiss in Oberkochen had become a supplier of lenses for the 1600F/1000F cameras. Zeiss supplied the lenses Distagon 5.6/60 mm, Tessar 2.8/80 mm, Sonnar 3.5/135, Sonnar 4.0/250 and Sonnar 5.6/250 mm. Towards the end of the 1000 F production period a Dallmeyer 5.6/508 mm lens made by Cook and Perkins, England, was also available, but did not fully cover the full film format. Hasselblad 1000F and especially 1600F cameras are very rare on the secondhand market and usually not in working condition because of age, neglect, and a lack of spare parts and qualified repairmen. Many cameras suffer from corrosion of the chrome rims. A lot of lenses suffer from scratches, fungus, discoloration and separation. Cameras in good condition can therefore fetch fairly high prices. The 500C was produced to replace the F-series cameras. It changed the troublesome focal plane shutter for a leaf shutter in each C lens. The camera has continued for over 40 years with only minor improvements. A variation of the 500C was used by NASA for all their Gemini and Apollo missions. Most lenses were made by Zeiss in Germany but the very early 1600F lenses were made by Kodak. The designation 'V System' was not used until the launch of the H System. The name "V System" was not created until the development of the "H System"; with a new system premiering, Hasselblad needed a designation to differentiate the older product line.