Abstract: A telephoto lens system is provided having a first lens group of a positive refractive power, a second lens group of a negative refractive power with a variable air space, and a third lens group of a positive refractive power with a variable air space. All of the lens groups are shiftable during a focusing operation with the second lens group air space increasing and the third lens group air space decreasing when focusing is effected from infinity to a short distance.

Abstract: A protective helmet having an internal integral layer of reflective material and the method of constructing the same is disclosed. A first layer of catalyzed clear gel coat is sprayed under pressure into a helmet mold and allowed to dry. A second fog layer of clear gel coat is sprayed over the first layer to form a tacky surface upon which small double sided reflective chips can be sprinkled and brushed flat. The second gel coat is then dried thoroughly. A third backing layer of clear gel coat containing metal flakes is then sprayed over the second layer and completely dried. A layer of saturated fiber-glass mat is applied over the third layer to seal in the reflective chips and to eliminate any air pockets. Layers of fiberglass cloth are then applied over the mat and the fiberglass is completely dried. The helmet is popped from the mold, sanded and finished.