Multi-image is the now largely obsolete practice and business of using 35mm slides (diapositives) projected by single or multiple slide projectors onto one or more screens in synchronization with an audio voice-over or music track. Multi-image productions are also known as multi-image slide presentations, slide shows and diaporamas and are a specific form of multimedia or audio-visual production.
One of the hallmarks of multi-image was the use of the wide screen panorama. Precisely overlapping slides were placed in slide mounts with soft-edge density masks; when the resulting images were projected, the images would blend seamlessly on the screen to create the panorama. By cutting and dissolving between images in the projectors, animation effects were created in the panorama format.
The term multi-image is sometimes used to describe digital photo image computer programs that combine or change images on-screen, for photo montages, and image stitching.
Description Multi-image presentations were a unique form of communication to audiences of various sizes, to meet a variety of communication and entertainment needs. The use of projected photographic images such as lantern slides for entertainment and instruction dates to the mid-1800s. Others, such as L. Frank Baum had a traveling show (1908) that included slides, film, and actors describing the Land of Oz. Throughout the years improvements in technology took place and applications for multi-image continued to expand. During the 1960s, automated synchronized audio and slides modules became more common and found use in instructional environments.
In general, multi-image can be defined as being: Based largely on analog production tools and technologies including art and audio production and film-based photography. 35mm slide film has high resolution and color range and are based on grain and dye clouds rather than on a fixed raster pattern, which when projected often is perceived as being more realistic, uniform, and detailed than digital images. Line density for 35mm film was up to 3850 lines per inch, which at the time no video projection technology could match. Multi-disciplinary in terms of the types of skills required to create and stage multi-image presentations. Venue driven; multi-image presentations had specific requirements for the equipment and spaces they were intended for and presented in.
Multi-image business Multi-image as a business thrived during the 1970s and 1980s. Multi-image presentations ranged from single projector shows run by projector-viewerCaramate Projectors Provide an Economical Educational Tool to large events for business meetings and conventions where multiple shows would be presented and often were rear-projected by 24 or more projectors.
Creating and presenting multi-image productions involved a relatively large number of specialized skills, equipment, and facilities to produce. During the height of multi-image, a number of types of businesses were directly engaged in the industry which employed thousands of specialists that ranged from producers and designers, writers, artists, typesetters, photographers, photo lab technicians, audio technicians, programmers, staging specialists as well as others associated with these disciplines.
A professional organization, the Association for Multi-image International (AMI), was created and had numerous active chapters around the world. The AMI held an annual convention and multi-image competition. Local chapters of AMI in various cities also held regional competitions.
An entire industry grew around supplying the tools and equipment needed to supply and support multi-image production. Corporations who manufactured and sold basic equipment and materials used in the production of multi-image, such as 35mm slide projectors, film, slide mounts, soft-edge masks and other items. The list of suppliers for the multi-image industry was extensive with a number of companies attaining international importance for the products they produced, including Eastman Kodak, Wess Slide Mounts, Chief Manufacturing, Navitar and Schneider Optics. Manufacturers of highly specialized multi-image equipment such as optical slide cameras and slide projector programming hardware. Precise camera systems were developed for the multi-image market featuring pin-registered film movements capable of making multiple exposures, controlled backlit color light sources, motorized multi-axis compounds for precise positioning of artwork, and long-roll film loads. Slide projector programming computers and dissolve equipment and software was developed to synchronize the slides with the audio by providing precise time control over slide tray positioning and lamp fade rates needed to create multi-image animation. Programmer and camera manufacturers included Audio Visual Labs, Electrosonic, Clearlight Inc. Spindler & Sauppe, Marron Carrel and Forox. Companies who specialized in one or more of the general disciplines used in the production of multi-image and offered multi-image as a service; these ranged from companies or individuals such as photographers, slide services and photo labs to full production multi-image service companies, staging companies, and event production and communications companies. Additionally, there were individual contractors who served as producers, directors, and designers or provided other talents needed to create multi-image presentations.
Driven by changes in technology and by economic considerations, multi-image has been replaced by video presentations and by readily available computer based technologies such as laptop computers running PowerPoint and projecting through digital projectors. Visual presentation and photo and graphics editing software programs have allowed a wider range of communicators quick, flexible, and easy access to the tools and technologies needed to create presentations. Digital photography has reduced the need for laboratory services and complex equipment. The expansion and ease of use of desktop computing brought a close to the multi-image industry.
Multi-image production technologies
The art and business of multi-image drew from many older existing technologies. When a multi-image project was initiated, various overall management roles were required to provide direction, planning, and project management. These roles generally involved the activities similar to those found in other media industries, such as creative, visual, and technical directors, producers, production managers, and writers.
Often individuals with the various production skills would fill these roles as well as performing their production roles. Multi-image productions in general were deadline driven and it was common that the production process would be non-linear, allowing for multiple activities to take place with overlapping roles.
Art and multi-image design The visual quality of a presentation was based on using photographs and artwork created for use in the presentation as source material. 35mm slides could be used directly as they were originally taken, or re-photographed by design. Often the original photographs were masked or duplicated for positioning and sizing. In some instances, 35mm cameras modified for pin-registration were used to create animated sequences. The registered 35mm format was generally standard but square and masked images were developed and supported by slide mount manufacturers like Wess Mounts.
Through the use of multiple projectors set up to project onto a defined screen area, projected images could be designed as animations. Typical programmable multi-image animation effects included filmic effects; cuts, dissolves, fades; fading from one photograph or graphic to another at different rates and intensities, and the development of computer-controlled 'dissolve units' by multi image equipment developers was key to the unique 'live' aesthetic of multi image productions, progressively building images and text to form a completed statement, inserting images or graphics into frames or windows on screen, step by step movement of images across the screen area, and superimposing text or images into a background. The visual effects were electronically synchronized to precise recorded soundtracks of music, sound effects, and voice, based on the capabilities and limitations of the slide projectors and dissolve units and computer controller. Multi Image systems equipment were developed by Arion, Audio Visual Laboratories, Clear Light, Dataton, Electronics, Multivision, and Spindler and Sauppé.
Artwork produced for multi-image presentations in general was based on one of two forms of top-lit reflective copy artwork: Materials that were produced and copied as flat art directly to slides to be used in the production, or Color- or image-separated and layered photomechanical art that would be copied to high-contrast masks which were then used to create slides. This second process was called optical slide printing and was based on many of the basic principles from photomechanical prepress art used in offset printing, silk-screen printing, and cel animation.
Flat art was created by using a variety of standard graphic illustration techniques, using pen and ink, airbrush, paints, from clip art, colored paper, transfer lettering such as Letraset, and by copying from existing materials on a copy stand or on optical slide camera. Cel art, such as found in cel animation, was also used.
Art used in optical slide printing was based on the use of high-contrast photomechanical materials such as photomechanical transfers, black and white type, rubylith and other materials. Phototypesetting was done by a variety of means including the Visual Graphics Corporation PhotoTypositor and the Compugraphic EditWriter at companies that specialized in providing typography. When making artwork for multi-image presentations, photographs, transparencies, and film images or continuous tone film or airbrushed masks could also be used as part of the camera-ready artwork.
The color or image separated layers of artwork were pin-registered using a variety of standard copystand/animationstand pin systems techniques. including 1/4-inch, Oxberry, and Acme. The artwork was created on a light table or animation disc to provide back lighting.
Often the art was created based on a grid system. A copy of the optical slide camera grid or reticle was used to align the artwork elements. The use of the grid for alignment could be used to accurately position images and art elements throughout the process from the creation of the artwork to the final projected images. This process also allowed layers of the artwork to be interchangeable from slide to slide, images or graphic elements could be carefully placed on the screen relative to other images, and for combining parts of images or graphics by separate slides as in an animated sequence.
Audio production The audio track of a multi-image show provided a framework for the timing of the presentation and for the sequencing and animations of the slides. These were produced generally on -inch audio tape on multi-track tape recorders such as models by Crown, Fostex, Otari, Sony, Tascam and TEAC, which allowed for having two tracks or channels for stereo sound and one for the synchronization or click track which was used to encode and playback the signals for the dissolve units.
The synchronization signals could be as simple as multiple pulse tones, each with a unique corresponding command, to digital telemetry, directly addressing a programming computer such as an AVL ShowPro V or a Spindler & Sauppe Director 24Z. As time and technology progressed, timecode was used, with the programming computer chasing the timecoded audio tape and firing commands from a managed list of cues.