Submitted to Amer. Astron. Society Education Working Group Newsletter, June 1998
I would like to alert college astronomy instructors to a significant new instrument that can greatly improve student experiences with modest aperture telescopes. The I3Piece is made by Collins Electro-Optics of Denver, CO and includes an ITT image intensifier and S-20 photocathode, capable of 50,000 amplification, 60 lines/mm resolution and only uses a few kV versus classical intensifiers that required many kV. The unit is ruggedly packaged with 1.25 and 2 inch barrel options, and can mate with an eyepiece, video camera or CCD camera easily, with total lengths under 12 inches. I have recently had the privilege of working with its inventor, Bill Collins, at the Denver University Observatories.

When coupled with a typical video camera and monitor, one can readily deliver a better than visual limiting magnitude view of stars, clusters and galaxies. For reference, according to Roy Garstang at a recent AAVSO meeting, the limiting visual magnitude for a telescope of aperture d (cm) is 7.6 + 5 log d. The I3Piece is too sensitive to look at planets or the moon, but usually these bright object can be viewed without difficulty, by students. The real advantage of the device is how it can surmount the "fuzzy blob" view usually experienced by first-time telescope users, and deliver literally picture book quality views, even from light polluted sites. The I3Piece works best under clear skies, as it amplifies haze and clouds, as well as stars.

When coupled to our 0.7 meter at Mt.Evans Observatory, we were able to identify 17th magnitude stars in real-time on the monitor, viewing the calibrated cluster, NGC7006. Comparably outstanding views were obtained when used with our 20-inch Clark refractor at DU's Chamberlin Observatory in central Denver. My key point is that in either eyeball or video mode, the I3Piece will insure students won't leave the telescope session disappointed, because they will easily see the physical principles illustrated when we share with them views of self-gravitating systems of stars or star forming nebulae. I strongly recommend that instructors investigate the website,, or call 303-889-5910. I would be happy to compare notes as well. Contact, or 303-871-2135.
--Bob Stencel DU Observatories & Dept. Astronomy