Celestron EdgeHD 925
- 9.25 inch EdgeHD optics
- Aluminum tube
- StarBright XLT coating
- 2350mm focal length (f/10)
- 23 mm Axiom 2 inch eyepiece (102x)
- 9x50 finder
- 2 inch star diagonal for comfortable observation of objects close to the zenith
- new optical design for pinpoint star imaging over a large field of view
- Mirror locks hold the primary mirror in place to protect against mirror shifting
- Ventilation openings allow fast temperature adjustment of the primary mirror
- Fastar-compatible for photography with f/2
- Dovetail bar for CGE mount
EdgeHD 9.25 OTA
The EdgeHD (Edge High Definition) optics combine the compact design of a Schmidt-Cassegrain with significantly improved imaging at the edge of the image. This optical system not only offers the properties of astrographs, but also produces completely undistorted, sharp images right up to the edge of the large visual and photographic field of view. This not only corrects the coma outside the optical axis - as with other so-called "coma-free" optical designs available on the market (see also our test image) - but also the image field curvature!
The difference
Many optical systems are propagated as "astrographs"; however, they produce the coveted "pinpoint" star image along a curved image plane. On images taken with modern CCD cameras, the result is a noticeable curvature of the image field which increases towards the edge of the image field and becomes stronger the larger the chip is; i.e. the stars remain round, but are blown up into small rings ("donuts") towards the edge.
With the CELESTRON Edge HD telescopes, in addition to the coma, this image field curvature is also corrected out to the edge, so that even images with large CCD chips are completely sharp, with uniformly large star images over the entire chip - right into the corners of the image field.
This also significantly improves resolution and limiting magnitude compared to competing optical systems of similar aperture. The Celestron XLT multi-coating also helps the Edge HD optics to achieve a significant increase in performance compared to similar systems on the market.
The EdgeHD optics image three times flatter in the field plane than a standard Schmidt-Cassegrain. This means that the stars on the entire chip of a Nikon D3 or Canon 5D are imaged with limited diffraction!
In addition to the new optics, the mechanics and tube have also been completely redesigned. The innovations include:
Mirror locks
hold the primary mirror in any focus position without exerting pressure on the optical elements. The image always remains stable on the chip, even with long exposure times.
Ventilation openings
behind the primary mirror ensure rapid air exchange so that the optics cool down unrivalled quickly. Thanks to an air filter system, no dust gets into the tube.
HyperStar-compatible
With all EdgeHD tubes, you can remove the secondary mirror and replace it with the optional HyperStar optics. The result: Your standard Celestron EdgeHD telescope becomes a digital Schmidt design for your CCD or DSLR camera for photography in primary focus at f/2 (C8, C11) and f/1.9 (C14).
Adapted telecompressors (f/7.5) and Barlow lenses (f/20) are currently under development.
Axiom eyepieces
The Edge HD 9.25 is supplied with an Axiom eyepiece from Celestron. With 23mm focal length and 82° field of view, you get an impressive combination of magnification and field of view.
Celestron EdgeHD 925
Short profile
- 9.25 inch EdgeHD optics
- Aluminum tube
- StarBright XLT coating
- 2350mm focal length (f/10)
- 23 mm Axiom 2 inch eyepiece (102x)
- 9x50 finder
- 2 inch star diagonal for comfortable observation of objects close to the zenith
- new optical design for pinpoint star imaging over a large field of view
- Mirror locks hold the primary mirror in place to protect against mirror shifting
- Ventilation openings allow fast temperature adjustment of the primary mirror
- Fastar-compatible for photography with f/2
- Dovetail bar for CGE mount
Product description for Celestron EdgeHD 925
EdgeHD 9.25 OTA
The EdgeHD (Edge High Definition) optics combine the compact design of a Schmidt-Cassegrain with significantly improved imaging at the edge of the image. This optical system not only offers the properties of astrographs, but also produces completely undistorted, sharp images right up to the edge of the large visual and photographic field of view. This not only corrects the coma outside the optical axis - as with other so-called "coma-free" optical designs available on the market (see also our test image) - but also the image field curvature!
The difference
Many optical systems are propagated as "astrographs"; however, they produce the coveted "pinpoint" star image along a curved image plane. On images taken with modern CCD cameras, the result is a noticeable curvature of the image field which increases towards the edge of the image field and becomes stronger the larger the chip is; i.e. the stars remain round, but are blown up into small rings ("donuts") towards the edge.
With the CELESTRON Edge HD telescopes, in addition to the coma, this image field curvature is also corrected out to the edge, so that even images with large CCD chips are completely sharp, with uniformly large star images over the entire chip - right into the corners of the image field.
This also significantly improves resolution and limiting magnitude compared to competing optical systems of similar aperture. The Celestron XLT multi-coating also helps the Edge HD optics to achieve a significant increase in performance compared to similar systems on the market.
The EdgeHD optics image three times flatter in the field plane than a standard Schmidt-Cassegrain. This means that the stars on the entire chip of a Nikon D3 or Canon 5D are imaged with limited diffraction!
In addition to the new optics, the mechanics and tube have also been completely redesigned. The innovations include:
Mirror locks
hold the primary mirror in any focus position without exerting pressure on the optical elements. The image always remains stable on the chip, even with long exposure times.
Ventilation openings
behind the primary mirror ensure rapid air exchange so that the optics cool down unrivalled quickly. Thanks to an air filter system, no dust gets into the tube.
HyperStar-compatible
With all EdgeHD tubes, you can remove the secondary mirror and replace it with the optional HyperStar optics. The result: Your standard Celestron EdgeHD telescope becomes a digital Schmidt design for your CCD or DSLR camera for photography in primary focus at f/2 (C8, C11) and f/1.9 (C14).
Adapted telecompressors (f/7.5) and Barlow lenses (f/20) are currently under development.
Axiom eyepieces
The Edge HD 9.25 is supplied with an Axiom eyepiece from Celestron. With 23mm focal length and 82° field of view, you get an impressive combination of magnification and field of view.
Celestron EdgeHD 925
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