Canon Zoom Lens FDn 100-300mm f:5.6  w/ End Caps 

This was an affordable high magnification zoom lens covering the continuous range of focal lengths between 100mm and 300mm which were frequently used among telephoto lenses.

By using a new aberration compensation method, well-balanced compensation is performed on various aberrations including astigmatism, coma aberration and chromatic aberration, providing excellent image quality at all focal lengths from maximum aperture, while also being made compact to the telephoto ratio of 0.81

Moreover while having a high zoom ratio of 3x the lens adopts a 1 focusing ring system in which zooming and distance adjustments are performed using a single ring, offering excellent operability.