File:RitcheyTelescope.jpg
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RitcheyTelescope.jpg (623 × 480 pixels, file size: 161 KB, MIME type: image/jpeg)
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DescriptionRitcheyTelescope.jpg |
English: Ritchey 24" reflective telescope
This picture was taken in July 2004 from an exhibition at Chabot Space & Science Center in Oakland, California. The caption of the exhibit said: Ritchey 24-inch Reflecting Telescope
The first important telescope built by George Ritchey (at Yerkes Observatiory in Wisconsin) was the 24-inch reflector you see here. He made the primary mirror (an f/4 hyperboloid) in his shop and Francis G. Pease worked on the cassegrain secondary mirror. Ritchey later photographed many nebulae with this telescope. The pictures were the first opportunity astronomers had to see the true forms and complicated structure of nebulae like the Orion Nebula. But more importantly, the photographs convinced astronomers that reflectors would be the large telescopes on which future research would be based. The telescope is on a German equatorial mount. The mirror is silvered glass 23.5 inches wide by 2 and 5/8 inches thick. The bottom of the mirror is supported at three points and at the edge. The skeleton tube, 7 feet long, held the secondary mirror and photographic accessories. The eyepiece position has an elaborate stage (brass) with a 2 and 1/8 inch threaded opening. The entire stage can be rotated as well as moved precisedly in either axis. The holder is designed for use with a photographic plate. The drive mechanism (in the .... <the rest of the text were hidden from view> |
Date | 15 July 2004 (original upload date) |
Source | Own work |
Author | Kowloonese at English Wikipedia |
Licensing
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I, the copyright holder of this work, release this work into the public domain. This applies worldwide. In some countries this may not be legally possible; if so: I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law. |
Original upload log
- 2004-07-15 20:33 Kowloonese 623×480× (165136 bytes) Ritchey 24" reflective telescope
Items portrayed in this file
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15 July 2004
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Date/Time | Thumbnail | Dimensions | User | Comment | |
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current | 18:55, 23 July 2009 | 623 × 480 (161 KB) | Toontje | {{Information |Description=Ritchey-Chrétien telescope |Source=en Wikipedia |Date=15. Juli 2004 |Author=Kowloonese |Permission=Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Ve |
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Metadata
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Camera manufacturer | SONY |
---|---|
Camera model | CYBERSHOT |
Exposure time | 1/40 sec (0.025) |
F-number | f/2.8 |
ISO speed rating | 100 |
Date and time of data generation | 14:10, 10 July 2004 |
Lens focal length | 8 mm |
Horizontal resolution | 72 dpi |
Vertical resolution | 72 dpi |
File change date and time | 14:10, 10 July 2004 |
Y and C positioning | Co-sited |
Exposure Program | Normal program |
Exif version | 2.2 |
Date and time of digitizing | 14:10, 10 July 2004 |
Exposure bias | 0 |
Maximum land aperture | 3 APEX (f/2.83) |
Metering mode | Pattern |
Light source | Unknown |
Flash | Flash did not fire |
Color space | sRGB |
Custom image processing | Normal process |
Exposure mode | Auto exposure |
White balance | Auto white balance |
Scene capture type | Standard |