Reflections On Projections
When You Want Big Pictures, Projectors Rule
Growing up in the 1950s, I remember envying a friend who lived down the block, because his dad took their vacation pictures on slide film and projected them. I marveled at the 6' wide Kodachrome majesty of faraway places like Yellowstone, Yosemite, and the Grand Canyon. Sure, the presentation was a tad crude by today's standards, the slides clunk-whacking their way through a manual, push-pull feed projector, occasionally upside-down and frequently popping out of focus. But the almost-real quality of transilluminated transparency film beat the socks off my dad's 3x5" drugstore prints, with their unpredictable density and color.
In my teens, I took up photography as a serious hobby. Immersing myself in darkroom technique, attempting to master the subtle science of negative/ positive printing for my "artsy" compositions. However, I never wavered from my conviction that slides were most effective for reliving and relating one's travel experiences.
Projection technology evolved rapidly over the ensuing couple of decades. Kodak's high capacity, round Carousel slide tray helped eliminate the pregnant tray-change pauses during presentations, as well as facilitating continuously repeating demonstration programs. The advent of autofocus projectors dealt effectively with the slide "popping" problem. Solid-state electronics resulted in versatile programming units that allowed a multitude of dazzling on-screen effects. The level of sophistication possible was now limited only by your imagination.
From the mid-70s to '80s, I had the good fortune to experience several of Kodak's "Visions in View" multimedia programs that toured the country. Utilizing several pairs of synchronized slide projectors, plus a turntable-mounted 16mm movie projector, it was slide showmanship at its inspiring best. Dean Collins' "Magic of Light" program, with its banks of 6x6cm Hasselblad projectors, was another high watermark in the industry. Many a multimedia career was sparked by these presentations.
To photographers familiar with the dramatic possibilities of slide projection, I'm preaching to the choir. This brief piece, then, is intended to present the "nickel tour" to those interested in exploring its potential. The following points are the basic considerations.
· Format. Manual projectors are available for formats up to 4x5" (and overhead models can be used with larger transparencies). While automatic, autofocus models are capable of sophisticated multi-effects presentations, they accommodate mainly 35mm and 6x6cm/6x4.5cm formats (there is an automatic, non-AF 6x7cm model, but it's expensive). The cost of 6x6cm projectors is approximately double that of an equivalent 35mm model. An option for 6x6cm shooters is to have high quality "super slide" (4x4cm) duplicate transparencies made, which can then be projected in some (but not all--check the specs) 35mm projectors.
· Tray Type. The round, Carousel-type tray introduced by Kodak has pretty much become the American standard. Most European makes favor straight trays. They take up less space if you store your slides as finished presentations, but 50 slide capacity is tops, with 40 the norm. Round trays have a standard capacity of 80 slides, with 100 and 140 slide models available for use with thin slide mounts. Thicker (and therefore heavier) slide mounts, used in 80 slide trays, are your best insurance against jamming.
· Slide Mounts. Forget cardboard mounts. Their extreme light weight, coupled with a tendency to develop ragged or bent corners with frequent use, can result in jamming, especially in gravity-feed projectors. That leaves plastic mounts, with or without glass. Glass mounts keep the film perfectly flat, avoiding "popping" out of focus. That's the good news. On the downside, they're more expensive; difficult to keep clean and dust-free when mounting; subject to breakage; and in humid climates, moisture trapped between the glass surfaces can result in "amoebas" wandering through the image during projection. Due to the greater degree of film curvature involved, glass mounts are pretty much mandatory for medium format projection. Two brands of plastic mounts popular with AV users in the US are Gepe (HP Marketing) and Wess (Wess Plastics); both companies offer glass and glassless mounts, in several formats and apertures.
· Lens Type. The choice of flat-field and curved-field, is determined by the type(s) of slide mounts used. Glass mounts require a flat-field lens. Since film bows slightly in glassless mounts, curved-field lenses can provide superior center-to-edge sharpness. If you are projecting a mix of originals and dupes (which may have a reverse curvature), or a mix of glass and glassless mounts, a flat-field lens strikes a better average. The moral is, try to avoid mixtures.
· Lens Focal Length. The lens should be chosen according to projection distance and image size desired (matched to the screen). To correlate these factors for classrooms, lecture halls, seminar rooms, etc., get a Kodak Projection Calculator and Seating Guide (publication S-16), which also considers room size, shape, and viewing angle. For home use in average living rooms with a 35mm projector, a 90mm lens will provide a 6' wide image at 15'; 8' wide at 19'; 10' wide at 24'. Consumer model 35mm projectors are usually supplied with a lens in the 85-100mm range, while more industrially oriented ("pro") models are priced sans lens. Zoom lenses are another option, letting you adapt to varying presentation venues.
· Projection Surface. No, not walls or sheets. A proper screen is important to image brightness, color fidelity, sharpness, and viewing angle. Smaller screens are usually constructed with folding tripod-type stands, while larger ones are typically wall or ceiling mounted. Generally, there are three types of screen surfaces: matte, for maximum image detail and viewing angle (the least light falloff for viewers sitting toward the outer edges of the seating area); glass bead, for a brighter image but narrower viewing angle; silver lenticular, provides good color and "focused" brightness, with a moderate viewing angle. This screen's lenticular pattern can be obvious in large smooth image areas such as sky. If you plan on projecting horizontal and vertical slides intermixed, or 6x6cm transparencies, be sure to use a square screen.
Although popular '50s-'60s projector brands such as Airequipt and Sawyers are gone, there are more than enough choices today for any level of indulgence. You can get a good 35mm projector for $250 or less, or spend thousands on sophisticated, heavy-duty models configured for professional AV (Audio Visual) presentations. Projector brands (35mm) available in North America include Braun (HP Marketing); Elmo; Kodak; Leica; Reflecta (Bogen Photo); and Rollei. Medium format (up to 6x6cm) models are available from Hasselblad; Kinderman (Argraph Corp.); and Rollei. Götschmann (Mamiya) has an automatic 6x7cm model. Manual models for 6x7cm, 6x9cm, 6x12cm, and 4x5" formats include Cabin and Götschmann (both from Mamiya); Noblex (R.T.S.).
The three models illustrated represent examples of the current state of the art. The Kodak Ektapro 9020 features a built-in dissolve control that fades slides in and out with just one projector (however, it still needs a second projector). It also has a high-brightness lamp module; auto lamp change in case of a failure; AV-slot and P-bus interface for multimedia applications; and super slide (4x4cm) projection with accessory condenser.
Rollei's Rolleivision twin MSC 330P is two projectors in one, facilitating single-projector dissolve presentations. Having the two lenses so close together makes screen alignment of the two images a snap. A PC serial interface allows advanced programming techniques via your computer, and a selection of top-quality Schneider lenses transmit the finest details in your slides. Optional accessories even allow 3D stereo projection (slides must have been shot as stereo pairs, of course).
The Hasselblad PCP 80 projector for 6x6cm and 6x4.5cm transparencies uses a round, 80 slide capacity tray. The PCP 80's unique perspective correction feature moves the lens upward (like the "rise" movement on a view camera), making it unnecessary to tilt the projector itself, thereby eliminating the "keystone" effect where the top of the image is wider than the bottom. Instantan-eous auto-switching of lamps avoids program interruptions due to lamp failure. The interchangeable Carl Zeiss lenses are accompanied by their own matched condenser sets. The PCP 80 readily adapts to multi-projector dissolve and multimedia presentations.
If you shoot 35mm, 6x6cm or 6x4.5cm, the Rolleivision 66 dual P accepts them all (but not 35mm and medium format intermixed). It features autofocus, automatic lamp change and fade, illuminated editing monitor, and multimedia adaptability.
Speaking of editing, some models from Braun and Reflecta feature lift-up rear projection screens that provide an 8.5" image for critical editing and small group viewing in normally illuminated room conditions, in addition to their regular projection capability.
To get involved in these exciting multimedia presentations, you'll need a means of aligning multiple projectors, dissolve controllers, audio-synch gear, etc. A company prominent in this area is Arion Corp. Their Stak-Mate 2 projector stand facilitates positioning two projectors placed one over the other for hassle-free on-screen image alignment. Among their several dissolve controllers and programmers, the Mirage 901 dissolve control offers many effects (variable-rate and reverse dissolve, flash, freeze, individual lamp control, etc.) at a reasonable price. They also offer Tascam four-track Portastudio stereo cassette recorders for adding synched music and narration, as well as many other related items. Money-saving combination packages of optimally matched components are available. Be sure to check out their newly redesigned web site.
This has been just a light once-over of slide projection. There are other considerations not touched on here. Such as the benefits of a good, color-balanced light table or box for editing; a full frame, focusable loupe for critical slide appraisal; slide mounting equipment; slide labeling units and/or programs; projectors with xenon light sources for long-throw auditorium use, etc., etc. But you should now have the fundamental knowledge necessary to ask the right questions when shopping for a basic projector setup for use in the home or classroom. If you do your homework and pay attention to a few simple details, you'll soon be producing impressive presentations that will draw eager audiences. Whether just family and friends, or larger groups of viewers, with everything else being equal, bigger is better.
Eastman Kodak Co.