An Easy Method for Preparing Presentation Slides Norman A. Wright' and Dennis D. Blevins2 University of Arizona, Tucson, AZ 85721
This paper describes a simplified method of preparing 35mm projection slides with a minimum of equipment and expertise, using information assemhled from various sources. The quality of the resulting transparencies compares favorably to professionally produced diazo slides. Twenty-five slides can easily he prepared in less than three hours. Material cost per slide is comparable to professional color slide processing. A two-step negative/positive photographic process is used. First, a high contrast black-and-white negative is made from the desired slide materials. Second, the negative is laid over Diazochrome" film for exposing and developing the final transparency. Each step is discussed in detail, including some helpful tips. The equipment and materials needed are listed below. 35mm SLR camera Extension tube set Copy stand or reversible tripod GE ECA 250 W white light bulbs Kodalith" Ortho Film, Type 3,6556 Kodalith" Developers, A and B Kodak Fixer Teenifax" Diazochromea KBL-P Developing canister and spools Negative sponge 250-rnl graduated cylinder 2 Glass plates or contact printer frame Sunlight, sunlamp, or carbon arc Developing tank or processing drum Pakon" plastic mounts or Quickpoint" mounts These materials are readily available and give satisfactory performance. No endorsement is intended by the use of commercial names. Procedure The copy stand which is partially homemade is shown in the fimre. Alternativelv. a reversihle triood mav he used. The lights are 250 W ( # f )photolamps with reghar spotlight
800
Journal of Chemical Education
This mpy stand, wilh tks dimensions, pwides optimum results using a shutlw speedof X sandan a m w e setting of 14. Different copy stands may significantly alter these exposure settings.
holders. It is imoortant that the lamos he oositioned at the same distance and the same angle from the ilide materials for even liehtine. A 35mm sinele lens reflex camera is mounted on the copy stand as sh&. Close focusing when photographing small objects is accomplished using extension tubes, bellows, a macrofocusing lens or a close-up lens set. Kodalith", with a film speed of ASA 6, is used. It is supplied in 100foot bulk rolls and must he loaded into 35mm cassettes. The bulk loader and cassettes are available from a photo supply. Because of the slow film speed, the camera, if auto-
-
' Present address: University of California, Riverside, CA 92521.
Present address: Smith Kline & French Laboratwies, 1500 Spring Garden St., Philadelphia. PA 19101.
matic, must be operated manually. Using a copy stand (as described above), an exposure time of 1' 4 s a t f4 is optimum. If the negative is too dark, i.e., overexposed, the material should be reshot a t an f - s t o ~% to 1 smaller (toward 5.6). Conversely, if the negative is iodiight, i.e., undeiexposed, the material should be reshot a t an f - s t o ~% t o 1lareer (toward 2.8). A copy stand with different dfmeksions may require significant changes in these settings with exposure times ranging to several seconds. Consult the exposure information supplied with the film to optimize your system. The exposed film is wound on spools and placed in a develooine canister in a darkroom or "lieht b ~ . The " develo~ina prliess'hay then be carried out in a lightrd;oum. Equal park ot stock Kodalith" A and R develowrsare mixed in a 250-ml graduated cylinder. The film is de;eloped in this mixture for 3 min with aeitation. auicklv rinsed with water or s t o bath. ~ wi& agitation. After fixing, ihe film and then fixid for 4 is rinsed under runnine water for 10 min. This Drocess is e outlined in Kodak ~ u b t c a t i o nS-26 ( I ) . ~ o l l o w i n i t h rinse, the film is w i ~ e dusine a neeative sDonee and hune to drv. . When dry,'the film rs cut k o convenient five-frame &ips (about 8lIv in. lone). I t is i m ~ o r t a nto t exercise care: cotton gloves sh&d be worn while handling the negatives to avoid fingerprinting. Using a light table, the negatives may be "touched up" with correction fluid or technical ink (a lettering pen with an 0 or 00 tip works best) to remove unwanted marks. The negatives are then ready to print. The Tecnifax" Diazochrome" (James River Graphics, South Hadley, MA) available from blueprint supply houses in avarietv of colors in addition to blue, comes in 81/2 X ll-in. sheets andmay be cut to appropriate size. The ~iazochrome' film is exposed between two glass plates (9 X 12 in.). This size plate holds up t o seven strips of five negatives or 35 slides.- he bottom plate is covered with paper to block reflected light. The Diazochrome' film is placed emulsion side up on the bottom plate. The edges of the negatives are marked to indicate where to cut the Diazochrome" after developing. Then the negatives are placed with their emulsion sides facing the emulsion side of the Diazochrome' film. The second glass plate is placed on top of the negative strips and held in place . contact orinter. commerciallv usine" lareer , . ~hinder c l i ~ s A available, is an appropriate substitute for dcveluplng n nun nlete XI., X I l -in. sheet at once. Next. the nlatrs are r~lacrdin birect &light for 2 min to expose the film. 1f sunlight is not available. a UV sunlamn . mav. be used althoueh the exDosure time will increase to about 5 min with less satGfactory results. Professionally, a carbon arc is used for this process. After the Diazochrome" is exposed, it is developed in ammonia vapor. A convenient developing tank is a glass paper chromatography tank with the rack still present. Place the tank in a fume hood and exercise care when working with ammonium hydroxide. About 150 ml of ammonium hy&oxide is poured onto a sponge in the bottom of the tank just before ~
~~~
~
~
use. The sheets of Diazochrome" film are suspended from the rack using clips. The tank is tightly covered and the film is developed for about 30 min or until a deep blue color develops. The film sheets are removed from the tank and air dried. A commercially available processing drum may be adapted for this developing process. After drying, the film sheets are cut into individual frame size for mounting. Pakon'plastic mounts (Pako Corporation, Minneapolis, MN) and Quickpoint" mounts are recommended. Both are durable, easy to use, and reusable. A little transparent tape on the edge of the film, not visible in the frame, prevents the transparency from slipping in the mount. T o euard aeainst incorrect nroiection after the slides are mounted, tge slide is oriented dithout inversion when inspected against a bright light for ease of display, and an adhesive, colored dot is attached to the lower left corner of the mount. When the completed slide is inverted for ~roiection. . " this dot is in the uppe; right-hand corner. Discussion A trans~arencvcan onlv be as good as the material from which it is made: The preparation of the material has been discussed in detail (2-4). The ACS Standard Abstract Form (5) and Kodak Publication S-22 (61, provide excellent guidelines. The best material for makine a slide is the orieinal. Drawings shuuld he made with the heaviest possible lines (pen tip 1 or larger). l4nteri;il should he twed usinr a rarhon rlhl~on limiting tGe copy to nine double-spaced or i 7 single-spaced lines. Maximum line lenath for elite t w e is 52 characters and for pica type. 43 charac~ers.crowdin-iof iniormation on the slide should he avoided since t h i ~audience must he ahle to rmd what is on the slide; what looks well-spaced on paper may be a disaster on film. A two-step photographic process has several benefits. The negative may be treated selectively to prepare the final slide. Masking of edge lines, figure captions, and removal of extraneous marks will allow only the desired information to appear on the slide. 'l'he ncgati& may hr used repeatedly tomnke transparencies, not merely duplicates, but replacements for sl~deswhich ha\,e faded with aee and use. These slides are easv to make, requiring minimal effort to obtain professional results.
-
~~
~~~~~~~~~
Literature Cited (1) '"kern-TextSlido.: KcdskPublicstion No. S-26,EBdmanKcdskCo.,Motian Pidure and Audiovisual Markets Division, Rahester, NY. (21 Meyer-Hartwig, K., Bleifeld, W., and Hegewsld, U.,"How to Compose Slidefar Lectures," Cerhard Witzstrock. Bsden-Bsden, 1377. (3) Kemp, J. E.,"Planningsnd Producing Audiovisual Materials,"3rd d.,ThomaaCmwell Co.. New York. 1975. (41 Minor, E., and Flye, H. R.. "Techniques for Producing Visual lnrtrunional Medis: 2nd 4.. McGraw-Hill, New York. 1977. (51 ACS Standard Abstract Form, American Chemical Society, Washington, DC. (6)"Effective Lecture Slides: Kodsk Publicstion No. S-22, Eaatman Kodsk Ca., Motion Picture and Audiovisual Marketa Division. Rochester, NY.
Volume 61 Number 9
September 1964
801
