ASTRO-PHYSICS
305mm F/3.8 Riccardi-Honders Astrograph
History of the Riccardi-Honders Design
This telescope is the first of its kind. The design of the Astro-Physics 305mm f/3.8 Astrograph is based on Klaas Honder's original idea of a fast optical system using a crown glass objective and meniscus correcting mirror in a Newtonian configuration. By adding a secondary mirror and field lens, Italian designer Massimo Riccardi was able to design an ultra-fast astrograph using only crown glass elements. Astro-Physics has added our 30+ years of telescope design experience to create a truly unique and fast astrograph to take full advantage of today's CCD imaging cameras. Imagine how quickly you will collect photons for the wide-field images that you plan to shoot.
Astro-Physics Version
The Astro-Physics design is a modification of the Riccardi-Honders. It features diffraction-limited performance over a huge 3-degree field, which is ideal for capturing large faint nebulae over a wide wavelength range. The design has essentially perfect color correction from 400 to 1000 nanometers (UV to IR), is fully corrected for all 5 Seidel aberrations (spherical, coma, astigmatism, field curvature and distortion), as well as longitudinal and lateral chromatic aberration. Multi-coatings on all optical elements ensure very high-contrast images.The primary Mangin mirror has a rear reflection surface. This means that the reflective surface has almost no scatter and it will not degrade over the years due to exposure from the air like an ordinary front surface mirror. Consider these advantages:
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The 305mm f/3.8 Riccardi-Honders Astrograph prototype was introduced at the Northeast Astronomy Forum (NEAF) on April 18, 2009. It was shown with the 305mm f/12.5 Maksutov-Cassegrain prototype on our 3600GTO German Equatorial Mount. Roland Christen had discussed the advantages of the Riccardi-Honders optical design in his presentation entitled "Optical Design for High Resolution Imaging" at NEAF the prior year, so it was fitting that we chose this venue to introduce our newest telescope. |
The Results Speak for Themselves!
| Click the links below to view Roland's images taken with the 305mm f/3.8 Riccardi-Honders Astrograph from our light-pollluted suburban location.. | |||
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| NGC7000 - North American Nebula (Hubble Palette) | Lower Right Crop from NGC 7000 | ||
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| Crescent Nebula in Milky Way - Two-Frame Mosaic | |||
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| Spiral Galaxy M106 | Center Crop of M106 | ||
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| M81 and M82 | |||
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| NGC 7822 at Half Resolution (to fit your monitor) | Crop #1 from NGC 7822 - "guppies" | Crop #2 from NGC 7822 - "fingers" | ||
| Click here for the full resolution, 3326 x 2504 pixel image! (File is over 1 MB.) | ||||
Specifications
| Clear aperture |
12" (305mm) |
| Secondary mirror size |
5.9" (150mm) |
| Focal length |
45.6" (1159mm) |
| Focal ratio |
f/3.8, Airy disc size 5 microns |
| Field size |
Diffraction-limited over 3.0 degree field - 60mm circle |
| Tube assembly |
14" (36cm) diameter x 21" (53cm) long, focuser
adds 4" (10cm). |
| Dewcap |
Machined aluminum dewcap, internal baffles as well as curved front edge baffle, black interior |
| Mounting rings |
Machined aluminum rings, ribbed to reduce weight, felt-lined |
| Weight |
Tube with focuser, without dewcap: 58 lbs (26.2 kgs) |
| Diameter of corrector cell |
14.50" (368.3mm) |
| Focuser (removable) |
3.5" ID Focuser, rack and pinion with FeatherTouch Micro 9:1 dual-speed reduction, 1.25" (31.8mm) travel, 2.7", 2" and 1.25" adapters |
| Back focus |
With 3.5" Focuser: 3.95" (100mm) from focuser housing (no adapters) |
| Mirror coating |
96% enhanced and protected aluminum |
| Corrector coating |
Broadband multi-coatings both sides |
| Carrying case for main tube of telescope |
Wood case with grey vinyl covering. Telescope is
supported on two foam lined wood brackets. Case is lined with foam and velour. Removeable wheels. Dewcap
does not fit in case. Dimensions: 29"L x 19.5"W x 19"H (74cm x 50cm x 48cm), including hardware Weight: 40.5 lbs (18.4kg) |
As of this writing in August 2015, we will produce additional
instruments later in 2015 and continue
deliveries as they are completed through the beginning of 2016.
We typically maintain notification lists so that we can notify prospective customers when the scope is available
to order. Please refer to our availability page for more
information on our notification lists. If you are interested in the 305mm Riccardi-Honders Astrograph and are not already on the notification
list for this instrument, you can sign up on our online
notification form. An automatic confirmation e-mail will be sent to you
for your records. Refer to Notification
Update periodically to find out the status of our mount and telescope
production runs - what we are making throughout the year.
Price: $20,500
Recommended Accessories and OptionsThere are many other accessories to consider. Please refer to these sections for additional recommendations:
Visual Accessories
Photographic
and CCD Imaging Accessories
Baader Planetarium Filters
Mounting Plates - your choices will be determined by the mount you own.
Specifications subject to change without notice.
Back to topCopyright © 2010 Astro-Physics Inc. All
rights reserved.
Last modified:
October 31, 2015
Astro-Physics,
Inc.
11250 Forest Hills Road, Machesney Park, IL 61115, U.S.A.
Phone: 815-282-1513 Fax: 815-282-9847