The SkyWatcher 250 Quattro is a Newtonian telescope with the super fast focal ratio of f/4. If compared with a f/5 telescope, the photographic exposure with a f/4 system is 40% shorter, making it a great time saver. This instrument is ideal for astrophotography and when used with the SkyWatcher aplanatic coma corrector, it will deliver sharp images across a large flat field.
The 2" Crayford focuser is solid, precise and backlash free. It operates at two speeds due to the 10:1 reduction mechanism for an extra fine focusing adjustment, which is paramount for astrophotography and high resolution observations.
The secondary mirror is oversize in order to have a fully illuminated field and to avoid any vignetting. It is collimatable by using 3 grub screws and the offset can be adjusted by using the central spring loaded screw.
The primary mirror sits on a 9 points cell and it is collimatable with 3 pairs of push & pull screws.
Both mirrors are made in borosilicate glass which have low thermal expansion coefficient. That means that the precise optical surfaces of the mirrors remain the same while the glass will cool down.
The aluminium tube is internally blackened to avoid internal reflection, enhance contrast and to absorb stray light.
