Movie Makers (Jan-Dec 1949)

22 BETTER-NOT BIGGER In connection with your November Clinic item. Critical Focusing, by Terry Manos, ACL, and William Berger, ACL, I wish to report that I have tried using their accessory lens arrangement for the visual focuser on the Bolex H camera. My results so far show that (T) the recommended Series V Portra 3 plus lens does not give a 3x magnification of the original image seen in the visual focuser, and (2) that the Series VI is the more desirable size in any case, since it fits without having to file away the edges of the eyepiece. While the latter point might be regarded as a detail easily corrected, what is the answer on the magnification matter? DONN LUNDE St. Paul. Minn. The answer is that the Messrs. Manos and Berger were wrong in making such a claim, as was Movie Makers in publishing it. Upon further examination of the suggested setup, it is clear that little (if, in fact, any) magnification of the image is created by the Portra 3 plus lens used in this way. It does, however, facilitate a more critical focusing of this image — thus making for a better, if not bigger, view of the subject. To those readers who have been equally misled bv this partial inaccuracv, Movie Makf.rs offers its sincere apologies. AUXILIARY ADAPTER The device shown in quarter-section in the central part of the drawing on this page has added materially to the flexibility of my lens equipment. This auxiliary adapter was turned in a lathe from a piece of brass rod. Its walls should be made as thin as possible to reduce weight to a mini AUXILIARY ADAPTER for combination lens attachment, designed by Lawrence E. Baty. mum. The inside diameter of the shank (D-l) is about 1/1000 of an inch greater than the outside of the lens barrel. The extreme diameter ( D-2 ) is slightly less than the inside hub diameter of the combination lens attachment shown to the right. Additional adjustment between the lens barrel and the adapter may be obtained by cutting the adapter shank lengthwise into four or six segments. This may be done with a fine hacksaw. The standard combination lens attachment has a similar adjustment on its hub. Length (L) should be chosen so that the adapter will slide entirely to the back shoulder of the lens barrel, and yet accommodate any standard attachment (such as the closeup accessory) that fits to the outer lip of the lens barrel. Otherwise, the dimensions of the auxiliary adapter are unimportant. In addition to the possibilities of the combination lens attachment as pointed out by the manufacturer, I have found that a standard line of closeup lenses will fit in this combination with an easy-to-make fitter, paper or metal. This permits greater variety in all forms of closeup filming. Lawrence E. Baty, ACL Salt Lake City, Utah SPREADING THE PICTURE A 25 cent concave lens from a war surplus supply house provides an extremely easy and inexpensive solution to the problem of projecting large-size movies in a small room. Held about 2V2 inches in front of the usual 1 inch lens of my 8mm. projector, a negative meniscus lens having a focal length of -124mm. and a diameter of 38mm. completely filled a 37 by 50 inch screen at 10 feet — instead of the usual 15 by 20 inch picture available at this distance. The large diameter of this cheap lens permits use of a very small portion of its center, thus reducing all types of distortion to an insignificant point. Several ways of mounting the lens will suggest themselves, but a removable bracket made of scrap aluminum, brass or tin is probably the best. Pictures, plans and ideas to solve your filming problems CONTRIBUTORS TO The Clinic are paid from $2.00 to $5.00 for ideas and illustrations published. Your contributions are cordially invited. Address them to: The Clinic, Movie Makers, 420 Lexington Avenue, New York 17, N. Y. Please do not submit identical items to other magazines. Mine was made of tin and fits around the takeup spindle bearing. The strip of metal is looped around this projection and a Vs inch screw clamps it tight. It is then bent out of the way of the reel, the upper end shaped to hold the lens and a similar screw clamp is adjusted. It is advisable to line both loops with felt or rubber, to protect the finish of the projector and to allow for expansion of the lens under the heat of projection. Henry Haar New York City FEATHERED SPLICES Many amateurs who use the dry splicer (including myself) get in the habit of moistening the emulsion to soften it once the dry scraper gets dull. There is no doubt that this step eases and accelerates removal of the emulsion and exposure of the base. I am now adding to this technique a feathering process, in which the two exposed ends are nicely reduced in thickness by abrasion. This is done with used emery boards from my wife's manicure kit. It seems to make no difference whether the fine or coarse abrasive is used, but care should be taken to observe which way the emery board was die-cut during manufacture. Use only with the burr upwards and away from the film to avoid the small groove that would otherwise be cut by the sharp edge. When correctly used, these emery scrapers make the neatest job of splicing I have found yet. Alan Probert, ACL Fairbanks, Alaska