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Bulletin of the Eastbay Astronomical Society
Founded in 1924 at Chabot Observatory, Oakland, California
Volume 77, Number 5, January 2001


Front Page.

Roberts Rules. President Carter Roberts’ message.
Sky Lore for the Month. Orion

Maintaining Your Basic Equipment By Jim Scala
Time for a Change. Introducing new Refractor Editor.


The Schmidt Camera and Amateur Astrophotography


Dr. Kenneth Lum
President, Peninsula Astronomical Society

Saturday, 6 January, 2001
General Meeting 7:31 p.m.
Lecture 8:20 p.m.
Astronomy Classroom, 2nd Level, Spees Building
Chabot Space & Science Center, 10000 Skyline Boulevard, Oakland, California



Image of Comet Hale-Bopp taken with a Celestron 8" f/1.5 Schmidt camera on April 7, 1997 from Lake Sonoma State Park in Sonoma County, California.
The Schmidt camera is a clever coupling of a spherical mirror and correction lens that permits wide-field images with exceptional acuity. The 48-inch Schmidt at Palomar Observatory generated the invaluable Palomar Sky Survey and is perhaps the premier instrument of this class.

This will be a summary of the life of Bernhard V. Schmidt, inventor of the Schmidt camera, from his birth in Estonia in 1879 to his death in 1935 in Hamburg, Germany. Being interested in mechanical experimentation from an early age, he sustained a traumatic amputation of his right hand at age 15 when a pipe bomb he was experimenting with accidentally detonated. He was subsequently educated in Goeteborg, Sweden and Mittweida, Germany. He set up an optical shop in Mittweida where he worked alone making excellent telescope mirrors for sale and taking on contract work with professional observatories. Schmidt finally obtained permanent employment at the Hamburg Observatory in 1926 where he went with Walter Baade, the great German, and later, American astronomer on a four-month eclipse expedition to the Philippines in 1929. During this trip Baade expressed the need for an aberration-free wide-field astronomical camera for survey work. Upon return to Hamburg, Schmidt invented and built the first Schmidt Camera in 1930 and showed it to be a camera capable of extraordinarily sharp, aberration-free images. He subsequently built one other camera before his death from complications of alchoholism in 1935.

The ‘secret’ of the Schmidt camera was revealed after his death by his Director in Hamburg, Richard Schorr, in Germany, and by Walter Baade in the U.S. in 1931 after his immigration. Within a short period after WW II, all of the old wide-field astrocameras based on portrait lenses were replaced by this remarkable innovation. Dr. Lum will show and demonstrate the operations of a Celestron Schmidt Camera at the meeting.

Dr. Kenneth Lum is an Emergency Department physician at Kaiser Medical Center in Hayward. He has been interested in astronomy since high school in Chicago where he made three telescope mirrors in the basement optical shop of the Adler Planetarium. He received his B.S. from the University of Illinois, Ph.D. from the University of California, Berkeley, and M.D. from Stanford University.
You can learn more about Schmidt cameras by visiting the Astronomy in California: 1850–1950 exhibit at Chabot Space & Science Center, and at
www.chabotspace.org/vsc/exhibits/califastronomy/schmidtcamera.asp.


DINNER WITH THE SPEAKER
5:27 pm, Saturday, 6 January 2001
PEARL OF SIAM RESTAURANT
5498 College Avenue, Oakland (510) 420-8600
Please call Betty Neall at 510/533-2394 by Friday, 5 January to confirm your place. Note the time has been advanced to allow everyone to be able to get to the meeting promptly at 7:31 pm.



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