Movie Makers (Jan-Dec 1952)

104 Let's make a nature movie: 2 Full screen movies of bees, butterflies and other insects are yours for the taking with a set of diopter lenses — and these homemade focal frames HERBERT D. SHUMWAY, ACL NATURE, in her infinite variety of tiny living creatures, offers every movie making fan a wide-open field for closeup filming fun. Birds and butterflies, caterpillars and the praying mantis, these only begin the roll call of radiant and wondrous life peopling the world around us. And the pleasant part of it all is that you can film these creatures with any camera that you now own. You don't believe it? Listen . . . Last month, turning our attention solely to bird pictures, we itemized the equipment necessary to that fascinating branch of nature filming. These items were (1) a medium (3x) telephoto lens, and (2) an electricallyoperated remote camera control. The lens you probably have already — or are going to buy. The remote camera control you can make yourself, for we outlined specifically its simple design. This month, turning to the techniques of filming insects, the problems become still simpler and their answers less expensive. In fact, a single ten dollar bill should put you in business for such closeup filming. So let's get going. When you first try closeup filming, you will run into three problems; but each one, fortunately, has a simple solution. The first problem is that of focusing your camera at extremely short distances. The second problem is that of determining accurately and quickly (without reference <^^0 FIG. 1: This set of Portra lenses (Nos. 1, 2 & 3) and the easilymade focal frames will adapt any camera to ultra-closeup filming. FIG. 2: Values A, B, C, D and F in the Table of Focal Frame specifications (page 125) are diagramed above. H, HH must be equal. to tables) the exact field covered by your camera lens. The third problem is that of devising some means of changing quickly both the focus and field size, so that you can film any sized bug that may come along. Let's consider each problem separately. EASY CLOSEUP FOCUSING The first problem — that of focusing at short distances — has been solved for us by the camera manufacturers themselves. The solution is simply to slip over your regular camera lens an inexpensive supplementary positive lens which can be purchased in most any camera store. Most widely known, perhaps, are those manufactured by the Eastman Kodak Company and sold as Kodak Portra lenses. Designated as plus 1. plus 2, and plus 3 diopters in strength, each one of these Portra lenses, when placed before a fixed-focus camera lens (or before a focusing lens set at infinity), will refocus that lens for a definite and close subject distance. For instance, a plus 1 lens will picture objects 3 feet away, a plus 2 lens will film objects 20 inches away, while a plus 3 lens will photograph those insects only 13 inches away. And that's really getting down close! But that's not all. These supplementary lenses can be combined in pairs for still closer filming. For example, by using two plus 2 lenses in combination you will have the equivalent of a plus 4 lens; with this you can film objects 10 inches away. Similarly, other combinations can be used to give you any desired focal distance. A plus 2 and plus 3 lens together will give you a plus 5 unit for filming at 8 inches; while two plus 3 lenses, the equivalent of a plus 6 lens, will focus your camera on a tiny bug only 6 inches away. SIMPLE ADAPTER RINGS For attaching these supplementary lenses to your regular camera lens, Kodak manufactures a simple adapter ring in sizes (called Series) to fit nearly any lens barrel. For using two Portra lenses in combination. Kodak also makes an additional retaining ring designed to hold the second lens in the adapter ring. Both of these items, as well as the supplementary lenses, you can buy at your local camera supply store. To use them, simply fasten the Portra lenses into the adapter ring and slip the whole assembly over your regular camera lens. Solving the problem of closeup focusing is just that easy! Now for the second problem — that of determining accurately the field size filmed by the camera. This is just as easily solved, not by commercially-made equipment, but by simple homemade equipment. Furthermore, the design of this equipment also solves the third problem in closeup filming — that of changing quickly both the focus and field size filmed by the camera. Let's consider in detail how this is done. First of all, examine carefully Fig. 1. Notice that there are several wire frames, each one of which is mounted on a strip of wood. Each of these frames is designed so