Kit #15: Reflective Movie Projector (2300 yen). There are certain machines that just look cool on their own, when they're sitting on the table doing nothing. This Gakken kit is one such machine. Keep in mind, though, that Gakken's mid-range 8mm projector kit (7500 yen) is the really good one; the reflective projector reviewed here is at the lowest end of the range.
Typically, film consists of some kind of transparent or translucent material (glass, or celluloid film) with the pictures etched, painted or exposed on to the material and then displayed onto a projection screen by passing light through the material and on through a lens assembly. In the case of film, as each frame advances in front of the light source (originally in front of a flame, more recently in front of a light bulb), a shutter blocks the light to prevent us from seeing the frame move. Because of the persistence of vision (afterimages left on our retina for a fraction of a second), we don't notice the flicker caused by the shutter closing and our minds are tricked into thinking that the "moving pictures" are really moving. In fact, the film is advanced one frame at a time and then held in place while the shutter is opened. The shutter closes again and the film to advance to the next frame.
I'm explaining all of this for one reason - kit 15 differs from a regular film projector in two extremely important ways. First, there's no shutter so we see the film advancing between frames. Second, there's no film. Rather, kit 15 uses a long strip of glossy paper with the images printed on it, and the paper strip is behind the light bulb instead of being between the bulb and the lens. The "light box" has 5 little mirrors that reflect the light onto the paper, and that light in turn is reflected from the glossy paper to the lens and then on to the projector screen. Hence the name "Reflective Projector". I can't find an internet site that discusses reflective projectors, so I don't know if they were used historically or not.
Kit 15 is another one of the more complex kits with over 40 pieces, and took it 2 hours to build. Functionally though it's just a gearing system that connects a handle to the film take-up sprocket. A little bar travels around in a circle, and once-per-revolution pulls the film forward the distance of one frame. The kit uses two AA batteries, but those are for the light bulb. The film is advanced manually, and the speed you turn the crank determines the speed of the film. If you turn the crank fast enough, you don't really notice the blurring caused by the film moving between frames, (shutter or no shutter). But, because the paper is fairly stiff and prone to tearing, I don't want to turn the crank too quickly. Speaking of the paper - the "film" is made up of a page of 12 strips of pre-punched paper, requiring that I again cut up the book. The strips are connected together using cellophane tape. It took as long to punch out the 300+ sprocket holes in the paper as it did to build the camera itself. The final film is 20 feet long, and takes about 2-3 minutes to watch (depending on the crank speed). One side of the film has clips of Astro Boy flying around, the other side has Honda's Asimo robot walking and dancing.
The mook is mostly dedicated to one topic this time, with pictures of antique movie projectors; articles on the theory of film and the history of moving pictures dating back to the "painted glass in front of an open flame" era; articles on some of the artists that made additional movies for the mook; and a how-to for using the Mac to print your own home-made movie on an ink-jet printer. There are a few other movies that can be cut out from the book, but they're not pre-perforated and require chopping up the book even more. The history of animation given in this book regards the older Japanese artists only.
The Otoko no Kagaku Magazine website has a series of links to people mentioned in the mook. The best link of the group goes to George Mather's descriptions of various forms of motion illusions. Norabbit's Minutes is one of the animations turned into a paper-strip film for the mook (available for purchase on DVD).
This is one of the more cool-looking kits if treated only as an art piece placed on a shelf. But, I'll probably try making my own film via Flash, and then printing it out and cutting the frames up. In this sense, the kit can be infinitely modified just by making more movies, although it's easier to just watch the movies directly in Flash on my laptop. The mook suggests one specific mod, and that is to take an LED from a hand held flashlight in order to make the projected light stronger for viewing. Instead, I've added a jack for a DC power adapter, and I'll try using a 6V supply with a 6V filament bulb.
Kit #11: Newton-style Telescope (2100 yen). I mentioned the Newtonian telescope back in my review of the Galileo-style telescope. The original refractive type scopes (Galileo and Kepler designs) use concave and convex lenses to focus the light at the eye. The drawbacks of these designs are that there's a limit to how big the glass lenses can get, and that the focal length of the lenses requires that the scope bodies get really long as the lens diameter increases. Newton overcame these problems by using a concave mirror instead of the first big lens. The mirror is placed at the back end of the scope, which effectively cuts the length of the scope at least in half, and it focuses the light onto a second mirror at the front of the scope which then aims the light at the eyepiece lens mounted on the side of the scope. The placement of the eyepiece also makes it easier for the operator to stand to the side to look at the image, rather than having to sit down at the far end of the tube.
The one drawback to Newton's approach is that the second mirror is right in the middle of your field of view, creating a blind spot at the center of the image. Fortunately, the blind spot is not normally noticeable on the larger scopes.
Gakken's kit #11 lets you build a little 2" scope. There are about 20 pieces, and the body of the scope is made of two sheets of stiff paper, held in place to the plastic end pieces via double-sided tape. The kit takes about 1 hour to build, and the only real drawback to the design is that the tape tends to lose its stick eventually. I'll probably need to glue the paper together after a few weeks. The scope's focal length can be changed by sliding the outer half of the scope (the mirror is at the back of the outer half) away from the inner half. The smaller mirror is very intrusive now, blocking maybe 20% of the incoming light. But, of all the kits so far, this is definitely the cutest one for just putting on the shelf and admiring. It's good for inspecting the moon and that's about it (I tested it the night I built the kit - magnification of the moon is about 1:1, but it brings the craters into really clear focus, and it's a lot less shaky to hold by hand than the Galileo scope).
This was the first Gakken kit to be missing parts. A couple of the other kits had some extra parts, but this one was missing a mounting screw for holding a support leg to the base plate. Fortunately, I had a spare screw left over from an earlier kit, and I was able to complete the scope easily enough. So, 1 missing screw from out of 14 kits; not a bad track record, quality control-wise.
The mook talks about Newton's original scope and gives a summary of some of Newton's discoveries regarding light and gravity. There's an overview of other types of scopes, a map of the moon, a demonstration of using a camera with the kit's scope, and a look at how to make a concave mirror by hand (polishing, etc.) Additionally, there's a history of space exploration, a description of a communications satellite, a suggestion for how to colonize the moon, and a look at Gakken's 3-vacuum tube radio. An author gets to learn how to make a light bulb, and there's also a look at hearing aid implants. Finally, there's an article on Einstein and Schrodinger. This mook is very science-heavy and I'd love to see it translated into English. But, there are no suggestions for modding the telescope this time.
The one mod I needed was to make caps to protect the eye piece lens and the interior mirror from dust and cigarette smoke. The wind-up doll's hat worked perfectly as a lens cap, and I cut out a page from the 101Tokyo Air Fair's exhibitor's guide book to make the end cap. The artwork from the guide book was Amano's painting of Gatchaman. Now, I have Gatchaman glaring at me whenever I look at the scope.
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