Two versions of the QUATTRO-8 OTA's are available:QUATTRO-8S with Steel TubeQUATTRO-8CF with Carbon Fibre Tube
(illustrated)CARBON FIBRE TUBE (QUATTRO-8CF only):
Carbon fibre is a strong and lightweight material and has much better thermal stability compared to a steel tube. This is especially important for astro-photographers dealing with long exposure times. Imaging telescopes made of less thermally stable material can deviate from optimum focus after long time exposures. With a carbon fibre tube, it can remain in focus for a longer period of time and long exposure images will stay clear and in focus.2" DUAL-SPEED LINEAR POWER FOCUSER (both models):
The new linear power focuser utilises 4 precision ball bearings to support the drawtube and provide great stability and zero image shift while supporting a heavy eyepiece or camera. Moving the drawtubeby the roller rather than a rack and pinion ensures exceptionally smooth operation, great feel and precise adjustability. The dual-speed feature has a second focus knob that has a 10:1 speed reduction to provide the super-fine adjustments even the most demanding users can appreciate.PYREX MIRRORS:
Both models feature paraboloidal primary mirrors made of low thermal expansion Pyrex glass resulting in substantially shorter cooling-down times.
- Highest Practical Power (Potential) x410
- Diameter of Primary Mirror 205mm
- Telescope Focal Length 800mm (f/4)
- Note: Eyepieces NOT supplied
- 9x50 Finderscope
- Parabolic Primary Mirror (Pyrex)
- 2" (50.8mm) Dual-Speed 10:1 Linear Power Focuser
- Tube Rings & Dovetail Bar
- 0.5mm Ultra-Thin Secondary Mirror Supports
- 77% more Light-Gathering than 150mm
note: equatorial mount not included
PARABOLIC PRIMARY MIRRORS
Features High Quality Parabolic Primary Mirrors to eliminate spherical aberrations inherent in 'fast' focal lengh reflectors with spherical primary mirrors. The mirrors are parabolized to bring all the light rays to the same focal point to give sharp, constrasty images, which are full of detail.
SKY-WATCHER DELUXE MIRROR COATINGS
Most reflectors today usually have a coat of aluminium as the mirror surface and then an overcoat of silicon monoxide or silicon dioxide to protect it. Silicon dioxide produces a much more durable coat than silicon monoxide but requires specialized equipment to apply it and is therefore more expensive. Protection is needed, because in most reflectors, the mirror is open to the elements and deterioration of the reflective layer reduces the resolution of the telescope.ALL Sky-Watcher reflectors are Multi-Coated with Silicon Dioxide as standard for Optimum Durability and Long Term Performance.
The new QUATTRO series with their fast f/4 focal ratios, have been specially designed for high quality astrophotography with short exposure times. They are of course also fine telescopes for visual observations. Tube interiors have knife-edge ray traced baffles.