Abstract: The invention provides a lens attachment adapted for use as a supplemental attachment to optical instruments, such as cameras, enlargers, when they are employed to form wide-ranging images upon a wide screen for example.According to the invention, the lens attachment comprises a master lens having focal length f.sub.M and a front member having focal length f.sub.A and a rear member having focal length f.sub.B, each member including cylindrical lenses, said front member and said rear member as a whole being located in front of said master lens, wherein said f.sub.B satisfies: 4f.sub.M .gtoreq..vertline.f.sub.B .vertline..gtoreq.2f.sub.MIn addition, the lenses are readily combined on a mount in fitting relationship with the use of tenons and recesses adapted to receive said tenons, thereby securing precise centering of the lenses.Thus, the distance between the rear member and the master lens is extremely shortened, and the diameters of both lenses are made substantially equal.