The Fascinating Renaissance of Slide Projection
(Part 2)
By Hermann Groeneveld / SilvergrainClassics
Crossfade technology with considerable hardware effort
With most manufacturers, you need at least two projectors to realize a presentation in crossfade technology, along with comprehensive accessories for a rather time-consuming installation before the presentation. The two projectors are combined with each other via an electronic crossfade system. The projection can thus be controlled manually. Or the system sent time pulses to the individual devices, which then automatically change the slides and also control the power of the lamplight. Complex slide shows can also be realized using software on a computer. In this case, not only the light and the sequence of the slides are regulated. The software also provides audio parts of the presentation (speech and music). One of the best-known brands and extremely popular with professionals because they were very robust, were the Kodak Carousel projectors. Kodak offered its own control system for crossfade projection, but it was also possible to fall back on cheaper third-party manufacturers, such as Kindermann. If you wanted to realize the presentation automatically and perfectly synchronized with its audio component, you still needed a special tape deck or tape recorder. This could record the control signals for the projection on its own signal track next to the audio track and play them back to the projectors via the control system. All in all, this resulted in a considerable hardware effort with several devices and a rather complex technology. And a lot of space was needed. Not to mention a high amount of time to be planned, from the realization to the installation of the finished presentation.
Two complete projection systems combined in one device
Rollei finally amazed the photographic world in 1976 with a compact solution for 35 mm slides: Probably the most ingenious slide projector of all time, the Rolleivision MSC twin, combines two complete projection systems in a single device. This enables crossfade projections with just one projector and from a single magazine. A complete blending system that can be conveniently carried in the case and is characterized by easy handling in the preparation, assembly and presentation of the slideshow. At the end of the 80s, the Rolleivision twin 35 digital P was a top-of-the-range device that could be connected to a PC with appropriate software or operated autonomously. The entire slideshow was then stored on either a floppy disk, a hard drive or a projector’s internal memory chip, which could be quickly replaced depending on the slideshow. Probably the most important advantage of the 300 series is the extremely quiet fan, which has been achieved through a more efficient cooling system. This makes the devices truly suitable for the living room. The MSCs are some of the quietest slide projectors ever made. An individual focus control ensures a sharp projection image. The autofocus system is designed as a so-called dual autofocus and acts separately on the two image channels. This is a solution that makes perfect sense for slides with different curvatures or different thicknesses. The automatic focusing does not take place via the lens, as is usually the case, but immediately before the crossfade through the slide plate. Thanks to this Rollei Pre-Focus system, active focus correction remains practically invisible on the screen. Another advantage of the MSC projectors is the ease of use: with just three clicks you can create a cross-faded slideshow from a magazine. Lasting value, high reliability and ease of repair round off the list of convincing performance features. Rollei’s MSC Twin projectors start at just under 300 euros on the second-hand market; a programmable version costs about 400 euros. In addition to the excellent personal advice provided by DiaVision, an exemplary DiaVision website makes it easier to Rollei Projector History – Chronologie newcomers to slide projection.
Free programming
The P in the name of the Rollei MSC twin series, such as 325P, 330P and 535P, indicates the programmability of the device. In addition to manual projection and real-time programming, the Rolleivision MSC 325 P offers the option of free programming, for example. Either via the 10-key keyboard on the projector or in conjunction with a computer with Windows. Each slide can be programmed with any fade time between 0.1 and 25 s, with a special effect and, if the slide show is to run automatically, with a slide life of between 4 and 600 seconds. The programming can be limited to a continuous part of the slide series, e.g. slides 10 to 35. Any order can also be set without having to change the slides in the magazine.
Computer Programming / Control
In the MSC 325P and 535P, all drive elements and lamps are controlled directly by two microprocessors. This provides the prerequisites for a wide range of functions and control via software on a personal computer. A PC can be connected to the 9-pin socket (serial port-9600 baud). However, hardware connections and software compatibility with current computer models and operating systems may no longer be available. With the Rollei software Dia-Edit Win and a PC with Windows, the comfortable programming of even long shows is particularly easy. All important information such as program number, slide number, fade time, slide time and special functions can be displayed on the screen in tabular form. In addition, each slide can be annotated and individual slides can be inserted and deleted. In addition, there are additional programs from many other manufacturers that go even further in their possibilities than Rollei’s own program can. One example is the open source software MinDia; which allows a prior simulation of the later projection on the computer screen. For this purpose, the slides must be scanned beforehand in low screen resolution. However, support for the software was discontinued in 2015. Another software that also works with more recent operating systems is TwinlightControl also available here.
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