McKeldin Planetarium - Annapolis, Maryland
Posted by: 
flyingmoose
N 38° 58.944 W 076° 29.562
18S E 370709 N 4315883
Planetarium located at St. John's College.
Waymark Code: WM139P2
Location: Maryland, United States
Date Posted: 10/20/2020
Views: 1
"The McKeldin Planetarium uses a Panasonic PTAE 4000 1080p digital home theater projector with a specially designed stack of two chromatically corrected lens assemblies. This design allows us to paint the entire dome with a geometrically corrected image of the whole sky from horizon to horizon. This assembly, along with portable heating and air conditioning units, was a gift of the St. John's College Graduating Class of 2010. The projector and lens assembly provide a reasonable image in terms of resolution and chromatic correction.
The projector is mounted to shine vertically and illuminate the center of the Planetarium dome. The projector is driven by an Linux-based (Ubuntu) computer running the Stellarium 0.10.2 planetarium program.
In addition, to "paint" the entire dome, the Panasonic 1080p shines this image of the sky through two concatenated lens assemblies. The first lens is a Raynox Digital CF185 Pro circular fish-eye conversion lens. This chromatically corrected lens is designed to provide a 185 degree field-of-view (FoV) for single lense reflex (SLR) and digital video cameras. However, this lens does not provide a full dome projection when used with the PTAE 4000 projector. We have therefore adapted this lens to our purposes by using a Raynox MX-3000 Pro Semi-Fisheye (0.3 x) chromatically corrected lens mounted on top of the CF185 Pro lens by means of a machined, aluminium adaptor shown in the pictures above. This assembly therefore provides a full dome projection with a dynamic range, flexibility, and resolution much greater than the original Spitz A-2 system.
We also do a fair amount of work during these classes to teach students to recognize the constellations as they progress through the months of the academic year. This is reinforced by the star gazing at the St. John's College Observatory. These observing sessions are held after seminars nearly every week throughout the academic year (weather permitting).
The McKeldin Planetarium and the St. John's College Observatory at St. John's College are open to the general public and to interested groups on an occasional basis." - (
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Plaque text:
McKeldin Planetarium
This building is named in horor of Theodore Roosevelt McKeldin, Governor of Maryland, 1951-1959 whose active interest and support contributed substantially to the growth of St. John's College.