I built this one and it works. Can use it for star testing your optics, but also refer to Dick Suiters book, "Star testing astronomical telescopes"
http://observatory.mvastro.org/libra...t/ArtStar.html
This design offers some advantages over the IIS article design, as it provides a smaller star, which means you don't have to place it as far away for a star test.
Hope you find it as useful as I did. Note, these days, ultra bright white LEDS are easy to find as bright as 20,000 or 30,000 MCD. The article refers to around 5000 MCD, so it's easy to exceed the brightness mentioned in the article,
Clear skies,
Nick