This practical instrument projects the Sun onto a viewing screen. The diameter of the projection is adjustable to 55 or 75mm. Easy and secure to use and therefore ideal to introduce children to the Sun, especially since more than one person can view the projected image at the same time. The optics consists of an achromatic glass lens, one plane and two convex mirrors. The projector can be adjusted from 0 to 90 degrees on its Dobsonian mount, and two quadrants measure the Sun’s declination. This device allows you to see sunspots and also is a great way to observe solar eclipses. Contents of the kit ✴ 8 pre-punched sheets of cardboard✴ 1 achromatic glass lens OPTI Media 569.OAL, 30 mm diameter, f = 250 mm✴ 2 convex mirrors 16.5 mm diameter, f = -10.2 and -14.0 respectively✴ 1 acrylic glass plane mirror 54 x 90 mm ✴ Instructions You will need to supply ✴ Standard solvent based all purpose glue, e.g. UHU, Evo-Stik Impact, B&Q All Purpose Glue. Do not use water-based glue: it softens and warps the cardboard, and doesn't stick properly to the printed surfaces. Solvent basedglues also dry much faster.✴ Double sided sticky tape for the plane mirror. Some solvent based glues candamage its reflective coating.✴ An elastic band for mounting the glass lens.✴ Two pieces of thin thread and two glass or metal beads for the quadrants.✴ A sharp knife with a fine point (thin carpet knife, craft knife, scalpel), to cut the thin holding tabs of the pre-punched parts.✴ A cutting board or mat, made from hardboard, plastic, or wood. Self healing cutting mats are ideal as the material re-closes after each cut.✴ For perfectionists: a black felt tip pen to blacken the white edges of the inner apertures, lens holder, etc. before construction. Size: 20 x 20 x 25 cm
