![\"50x50](\"http:\/\/stereo.thurstons.us\/content\/wp-content\/uploads\/2009\/02\/80x132twosizes.jpg\" "\\"50x50")
<\/a>slides in North America have commonly been mounted in dual-aperture, fold-over cardboard mounts with external dimensions of 80x132mm.\u00a0 These are thin, relatively inexpensive and available with several aperture dimensions.\u00a0 Common apertures are (WxH in mm)<\/p>\n- \n
- 50×50<\/li>\n
- 50×40<\/li>\n
- 40×50<\/li>\n
- 52×24<\/li>\n
- 52×46
\n(rare, but sometimes available)<\/li>\n<\/ul>\nThe mounts are available in differing weights and in black or white cardboard.\u00a0 The aperture choices provide cropping and composition choices as well as supporting those users of 645 cameras.\u00a0 Commercial viewers (like the King Inn and the Saturn) and custom viewers were designed around this mount dimension.\u00a0 None of these viewers are still manufactured, but the 80×132 format is alive and well.<\/p>\n
3D World – 2004<\/h2>\n
At the 2004 NSA convention in Portland, I first saw the 3D World products.\u00a0 They had their coin-operated sequential-viewer, a prototype of what would become the TL120-1 camera, a steal-the-light viewer, sample slides, and boxes of plastic slide mounts.\u00a0 The slide mounts were very expensive but I bought a couple of them to see what they were like.<\/p>\n
The original 3D World mounts were thicker and larger than the cardboard mounts to which I was accustomed.\u00a0 They were designed for use in the 3D World viewers and could not be used in the King In or Saturn viewer.\u00a0 These first edition mounts were about 4mm thick and had 54mm square apertures spaced at 65mm.\u00a0 This effectively put the stereo window of every image at infinity.\u00a0 Everything in every image was forced in front of the window and window violations were unavoidable.\u00a0 The mount halves were held together very poorly by sets of troughs and grooves.\u00a0 It was quite easy to say, \u201cThese mounts aren’t worth plastic it takes to make them nor the postage required to obtain them.\u201d\u00a0 Should you come across any of them, please destroy them.<\/p>\n
3D World – 2006<\/h2>\n
Sam Smith worked with 3D World to correct some of the deficiencies in their mounts and sometime in 2006 they\u00a0 released a second edition.\u00a0 These had the same same outer dimensions (80x140mm), but were only 2.8mm thick and had smaller apertures (52mm) spaced at 62mm.\u00a0 These new mounts were held together with six 1.8mm pins\/holes molded into the halves.\u00a0 They had a white writing-label, four adhesive film-tabs inside, and were plainly marked along the top, \u201cRevised by Sam Smith\u201d and between the apertures with \u201c62\u201d.\u00a0 These were a huge<\/em> improvement over the original mounts and, with them, precision mounting was possible.<\/p>\n
Two fundamental differences between the 80x132mm cardboard mounts and the 80x140mm plastic mounts are the vertical placement of the apertures, and the symmetry of the “front” and the “back”.\u00a0 The apertures on the plastic mounts are vertically centered and (in theory) the same size on the front and the back halves.\u00a0 The apertures on the cardboard mounts are located 11mm below the center-line and the round-corner apertures on the front-half are slightly smaller than the square-cornered openings on the back-half.\u00a0 In both of these characteristics I prefer those of the cardboard mounts.<\/p>\n
3D World – 2008<\/h2>\n