EAN: 050234115506
Sky-Watcher`s 7.5` f/5.3 Maksutov-Newtonian Telescope features a hybrid optical path that combines the parabolic mirror of a Newtonian with the front corrector plate of a Maksutov to create an optic that corrects for spherical and chromatic aberrations, and comas across the entire field of view. An added benefit of the front corrector plate is that the secondary mirror can be attached to it, reong the struts and supports found in traditional Newtonians and eliminating the diffraction spikes they cause which can degrade the image. The resulting views through the scope are bright and clear with virtually no distortion across the entire field of view with true color rendition.
The scope is equipped with a 2` Crayford-style focuser, instead of the more common rack-and-pinion, which uses a steel rod held tightly against the drawtube to provide a toothless friction system that eliminates backlash and enables ultra-fine, precision focusing with its 10:1 reduction micro-focusing knob. Employing a 2` drawtube allows the use of larger eyepieces and accessories.
While there is no mount included, a cradle-ring assembly is provided. It clamps over the optical tube and lets the user adjust the orientation and position of the scope relative to the mount to optimize viewing comfort and balancing, while avoiding interference with other equipment. A stainless steel Vixen-style dovetail plate makes it compatible with any alt-az or equatorial mount with a Vixen-style saddle, and a 1/4`-20 stud on the top of the cradle ring assembly enables a camera to be piggybacked onto the scope for wide-field photography.
Optical Performance
- 7.5` (190mm) aperture
- f/5.3 focal ratio
- 1000mm focal length
- Pyrex optical parabolic primary mirror further corrects spherical aberration
- Front corrector plate corrects spherical and chromatic aberrations, and comas (off-axis aberration) across the entire field of view
- Secondary mirror attached to corrector plate to eliminate diffraction
- Internal baffling reduces stray or unfocused light for bright and clearer images
- High-quality Schott optical glass elements
Mounting
- Requires user-supplied mount and tripod
- Cradle-ring assembly enables adjustment to the OTA orientation relative to mount
- Vixen-style dovetail plate
- Integrated 1/4`-20 piggyback camera mounting screw
Focuser
- Dual-speed Crayford-style
- 2` diameter drawtube to accept larger eyepieces
- Coarse-focus knob, 10:1 fine-focus knob
- Crayford focusers use a toothless friction system that allows for super-fine precision focusing without backlash
- Brass compression ring to protect eyepieces and accessories
Optical Accessories
- 9x50 right angle erect-image finderscope
- 42mm T-ring adapter to mount user-supplied DSLR camera, requires camera specific adapter
Sky-Watcher S11550 Specs
| Optical Design | Maksutov-Newtonian |
| Aperture | 7.5" / 19.0 cm |
| Focal Length | 1000 mm |
| Focal Ratio | f/5.3 |
| Eyepiece Barrel Diameter | 2" |
| Diagonal | None |
| Finderscope | 9x50 right angle erect-image |
| Tripod | None |
| Mount Type | Vixen-style dovetail plate |
| Power Source | None |
| Optical Tube Dimensions | Not specified by manufacturer |
| Weight | 29.0 lb / 13.1 kg |
In the Box
- Sky-Watcher 7.5" f/5.3 Maksutov-Newtonian Telescope (OTA Only)
- Cradle Ring Assembly
- 9x50 Right Angle Finderscope
- 2-Year Manufacturer Warranty
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