Laptop Dew & Light Shield
by Ron Keating

A laptop computer is a great companion to your telescope but you'd better protect it from dew. You'll also need to shield the light so it won't annoy others (as well as cover the screen with a red filter). The following instructions will help you build a custom dew and light shield that folds flat for storage.
Materials Needed:
  1. Decide how big to make your enclosure by setting up your laptop exactly the way you'll use it at the telescope. Tilt the display to the same angle you'll use and plug in whatever cables will be used in the field. Make it just large enough to meet your needs but resist the temptation to make it any larger. Don't put anything within the enclosure that isn't really needed (the power supply can usually go under the table instead of inside the enclosure).
  2. Start by placing panels of corrugated plastic along each side of the laptop working area. Use the computer a bit and make sure you have enough working room. This will be the "W" dimension (width) of the back and top panels.
  3. Next rest a corrugated plastic panel on the LCD screen and raise the front edge so the panel does not block your view of the computer screen. Bring the panel toward you until the front edge is directly above the front edge of the computer. This is dimension "T" of the top and side panels and can be increased for better dew protection, but it will make the enclosure larger.
  4. While performing step 3 the panel rested on the top of the LCD screen, but add about one inch and this is dimension "R".
  5. The bottom of the enclosure must be at least as deep as the laptop, but a few extra inches will make it more stable. Determine this point and measure dimensions "B" and "F").
  6. You are now ready to cut the panels. If you have some cardboard lying around you may wish to make a mockup first to insure you are happy with the dimensions.
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  8. Cut the top and back panels to the dimensions shown. All corners are right angles.
  9. Cut the first side panel as follows:
    • Starting at right angle corner "B - R", mark-off dimensions "B" and "R".
    • Keeping corner "R - T" aligned with corresponding corner of TOP PANEL, pivot side panel until dimension "F" is correct. Then use TOP PANEL to mark-off line "T". Finally mark-off line "F" from corner "B - F" to corresponding corner of TOP PANEL.
    • Now cut the first side panel along the lines.
  10. Flip the panel over to its back side and use it to mark and cut the second side panel. This ensures that they are "mirrors" of each other.
  11. Paint the panel interiors flat black to minimize reflected light and allow to dry.
  12. Lay out the panels as shown above with the inside surfaces up.
  13. Butt the edges of the Top and Back panels together and apply tape to the seam. Use several layers to give the joint some strength.
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  15. Fold the Back panel onto the Top panel (the taped seam acts as a hinge) and apply tape around the edges. You have now formed a hinge that allows the panel to be folded for storage.
  16. Flip the assembly over so the outside surfaces are face up. The Left panel should be on the left side as shown below.
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  18. Butt the side panels against the Top panel and apply several layers of tape to each seam.
  19. Fold the Left panel onto the Top panel as shown below.
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  21. Apply tape around the edges forming a hinge.
  22. Fold the Right panel onto the Top panel as shown below.
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  24. Apply tape around the edges forming a hinge.
  25. Now unfold the panels.
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  27. Apply Velcro to the lower rear corners as show in the photos above to hold the enclosure together when in use.
  28. The Velcro can be released for folding and storage.