Richardson's handbook of projection (1930)

1270 HANDBOOK OF PROJECTION FOR IMPORTANT.— It must be noted that in some instances different makes of lens will require almost exactly the same assembly, but that won't do at all. Exactly the right assembly must be used for each lens. For example, examining drawing No. 4 (Fig. 454), it is apparent that very nearly the same assembly is used for quarter size Ross lenses as is required for Cinephor Series 1. However, the Ross requirement is given assembly No. R-33, the only difference between it and R-32 being that the Ross adapter is B-324-R, the diameter of the Ross lens being not the same as that of the Cinephor Series 1 lenses. Citing another example, suppose we are using a 6-inch E. F. half size Ross lens. Referring to Fig. 451, and column headed "Assembly Drawing Number," we see that for the Ross Half Size lens, 5^4 to 6y2 E. F., drawing No. 16 is the right one, so since our lens is 6-inch E. F. we turn to it (Fig. 466), first having glanced at the column headed "Assemblies" in Fig. 451 and ascertained that assemblies R-35 and R-36 will be required. In Fig. 466 we find the assembly required for our half size, 6-inch E. F. Ross lens. We find that as supplied by the manufacturer our Ross half size lens will fit neither the front or rear Super Simplex lens clamp. We will need adapter assembly R-35 to cause our lens to fit the rear clamp and an extension tube (E-113-R) with threaded adapter A-188-R, to lengthen the lens barrel so that it may be properly held by the front lens clamp. NOTE. — Many Ross lenses are under the standard diameter. The one we are now considering happens to be one of these. It therefore will also be necessary to