The Celestron EdgeHD telescope: Corrected image - sharp right up to the edges!
EdgeHD is the name for Celestron’s “aplanatic Schmidt Cassegrain telescope”. After over 50 years of success, Celestron has revolutionised the classic Schmidt Cassegrain telescope.
EdgeHD telescopes ( "Edge High Definition") are true astrographs. This optical system delivers distortion-free, sharp images right to the edge of the visual field. This means that not only the coma outwith the optical axis is corrected, as is the case in currently available “coma-free” lens designs, but also field curvature.
Lots of optical systems are advertised as “astrographs”. As desired, they display stars with pin-sharp clarity, but along a curved image plane. Photographing this using a camera results in a noticeable image field curvature which rises towards the edge of the image field, resulting in increasing star size and aberations with larger sensors. The stars at the edge expand into small rings (“doughnuts”). As well as the coma, the Celestron Edge HD telescopes correct field curvature right up to the edge of the image. This also significantly improves resolution and magnitude limits in comparison to rival optical systems.
The XLT multi-coating helps to give the EdgeHD scopes a significant performance boost compared to similar systems on the market.
The Edge HD telescopes’ mechanisms and lens tube have been fully overhauled:
- mirror clamps hold the primary mirror securely in any desired position without putting pressure on the optical elements. The image is stable, even during long exposure times.
- Air vents behind the primary mirror provide fast air exchange so that the lens cools amazingly quickly. Thanks to an air filter system, dust is prevented from entering the lens tube.
The CGEM and CGEM-DX mounts
Astro photographers have been waiting a long time for this. The combination of Celestron's proven SC optics with an inexpensive, German mount that is easy to transport, mechanically precise and has outstanding drive electronics.
Sturdy construction, precise mechanical design "Made in the USA" and patented software result in the ideal mount for DSLR astrophotography with high load capacity and the necessary accuracy in positioning and tracking! From the solid connection between the tripod and the mount pole block, to the large azimuth and polar height screws, to the selected worm gears and the 3" tube prism clamp, everything has been mechanically rethought and improved. High-quality servo motors with planetary gears provide the drive technology basis for photographic tracking accuracy. Internal motor cabling and encapsulated, cold-resistant drive electronics help to prevent cable clutter and short circuits in field use. The Celestron drive software with patented All-Star Alignment procedure allows accurate alignment of the mount in a few minutes, even without a view of the North Star. A 16-channel GPS receiver is available as an option. Several pointing and periodic worm correction methods are available. Precise tracking is supported mechanically and by software up to 30° above the meridian. The dreaded "swing-through" of other mounts from east to west is eliminated. The price includes the ASCOM-compatible NexRemote pointing software on CD, which allows all functions to be controlled from home or in the car via a laptop. However, connections for SBIG or LVI SmartGuider also enable sub-arc second CCD tracking correction for DSLR photography without a PC or laptop.
Combination options:
A standardised 3" prism clamp allows secure and torsion-free mounting of telescopes of all types. The CGEM mount is therefore ideally suited for - and available in a discounted set with - Schmidt Cassegrain optics from 8 to 11 inches with maximum transmission (XLT coating).
All data at a glance:
- Positioning speeds: 5°/sec, 2°/sec, 1°/sec, 64x, 16x, 8x, 4x, 1x, .5x
- Tracking speeds: sidereal, solar and lunar
- Alignment for northern and southern skies
- Alignment routines: Auto Align, 2-Star Align, Quick Align, 1-Star Align, last alignment, (Hibernate = park position), Solar System Align
- Database with 40,000 objects and 400 programmable objects, extended information on an additional 200 objects.
- Flash upgradeable control software and motor control for downloading product updates via the Internet
- Meridian tracking – photography up to 30° above the meridian without interruption
- New "All-Star Alignment" for precise alignment without a polar star or pole finder
- New software with the following enhancements: Mount calibration, database filtering, last alignment (Hibernate), five alignment routines and programmable tracking speeds
- Special database with all popular deep sky objects, catalogued by name and catalogue number; the most famous double, triple and quadruple stars as well as variable stars and objects in the solar system
- Permanently programmable periodic error correction (PEC)
- Double-line, 16-character LCD hand controller with backlit LED buttons
- Includes NexRemote telescope control software for more advanced control of the mount via PC
- ASCOM and LX200 compatible.
About the mount:
- CGEM computer-controlled parallactic mount
- Ultra-stable 2" steel tripod with accessory tray
- Large 3" clamping device for mounting the telescope
- Tracking motors - DC servo motors with integrated optical encoders provide smooth and quiet operation and long life
- Internal cabling for easy setup and transport
- Optional GPS receiver can be retrofitted
- Power supply: 12V / 1.5Ah
- Steel worm gear and brass worm, 90 mm worm gear diameter
- Precisely manufactured pole shaft with 40 mm diameter supported by tapered roller bearings and ball bearings
- Connections: ST-4 / LVI-compatible autoguider port for external tracking cameras, Aux port for Internet software updates, autoguider and Aux port on the mount's electronics cover, RS-232 port on the hand controller for controlling the instrument with a PC, 12V safety power connection guarantees a secure hold of the plug
- Load capacity: 18 kg, the DX version even carries 22 kg
- Weight of mount without tripod and counterweights: 18.6 kg
Included in delivery:
- Counterweight 7.7 kg, for the DX version: 10 kg
- 12V car power cable
- NexRemote software incl. RS-232 cable
Please note: The counterweight bar and weights of the CGEM and CGEM-DX are not compatible, as the DX version has a thicker counterweight bar.
It not only matters which telescope you buy but also where you buy it. Our additional services:
- We are a leading telescope dealer and know the devices we sell. Our customer service team will gladly help you after your purchase if you have problems with assembly or operation.
- We provide a copy of the 80-page Telescope ABC beginners handbook with every telescope.
