This adapter mates the ST-7/8/9/10/2000 cameras with popular 35mm camera lenses for wide field imaging. Adapters are available for Canon FD, or Nikon. Note: Canon FD lenses are manual only. The CLA-7 cannot be used with a filter wheel, but it can be used with the male-to-male t-thread adapter in place of the threaded barrel to hold a 1.25" filter behind the camera lens.