This photo Kowa TSN-PA6 600mm Focal Length SLR attachment carries a fixed focal period of 600mm which enable it to be part of Kowa TSN-PA6 600mm Focal Length SLR both film and dslr cameras. This adapter replaces Kowa TSN-PA6 600mm Focal Length SLR the eyepeice from your recognizing scope plus the lens from the camera effectively making the recognizing scope you Kowa TSN-PA6 600mm Focal Length SLR guessed it-your camera lens.