Movie Makers (Jan-Dec 1951)

FIG. 4: Measurements (left) of start and end camera positions must be made from film plane, not taped-off blocking points. FIG. 5: A 42 to 24 inch zoom of alarm clock for double exposed scene called for extra velvet to hide electric cord. FIG. 6: Zoom shot can be made with equal facility when titler is in horizontal setup shown. The twin problems of camera movement and follow focus create no challenge to this filmer. He forgets the one and avoids the other with this hand-propelled method of camera movement. The results, as far as I can see, have been satisfactorily smooth. However, if you are quite critical — and can sacrifice some depth of field — still smoother results probably could be created by shooting at 24 or even 32 fps. Remember, though, that 8 or 16 more frames are being exposed for a given time unit of camera travel. Thus, if you wish your zoom to maintain its same rate of acceleration in the screen image, the camera must be moved more swiftly during the time unit. FOLLOW FOCUS AVOIDED So much for technical problem No. 1 — camera movement. In effect, my answer seems to be: Don't worry about it. Problem No. 2 — accurate follow focus — is quite another thing. For, as Mr. Merz suggests, changing the focus of one's lens during the brief moment of shooting a zoom takes quite some doing. It may be almost impossible to do it well manually; and, to my thinking, the technical setup is too complicated to bother doing it mechanically. Hence my answer to problem No. 2 has been, simply: avoid the necessity for making any change in focus. Sounds like magic? Well, here's how . . . MEASURE FROM FILM PLANE I have spoken earlier of my methods of determining visually the suitable beginning and end points of a zoom's path of travel — and then of taping the tracks so that these terminal points would be maintained in actual operation. My next move is to measure the distance between each of these two points and the title (or filming) area. But get this clear! I do not (and you should not) measure the distance from the two taped blocking points to the filming area. What we are interested in knowing is where the film is, in relation to the filming area, when it starts moving and where it is when it stops. Thus, you must measure from the film plane positions (not the blocking points) at the beginning and the end of your zoom (see Fig. 4) . SETUP ,FOR TRAVEL TITLE A concrete example will make this completely clear. For a recent travel film I decided to combine the familiar closeup of a spinning car wheel with the names of places visited double exposed on this background. But to give these transitional shots an added feeling of forward movement, the double exposed place names also were to zoom in sharply from back to front, from small to large in letter size. If you will assume that I have already shot the background footage, here was the setup for the zoomed title words. With my titler in its vertical operating position, a piece of black velvet was stretched on the baseboard and the place name "Derby Line, Vt." lettered out on it. The camera was then drawn upwards on the twin tracks until these letters were (through the viewfinder) quite small but still legible (see Fig. 1). This upper, or beginning, camera position was then taped off and measured. The distance — from film plane to title area — proved to be 42 inches. In an experimental dry run. the camera was then pressed down the twin tracks until, through the viewfinder, the lettering just filled the field of view (see Fig. 2). This camera position was then taped and measured — again from the film plane. The distance to the title area was 24 inches. FINDING RATE OF TRAVEL Now several dry runs were made from top to bottom to determine the most effective rate of camera travel over the 18 inches of track between the 42 and 24 inch camera positions. The rate finally decided on completed the zoom in 314 seconds of screen time, during which there were exposed (at 16 fps) 52 frames [Continued on page 340]