SKYWATCHER QUATTRO 250 f/4
Sky-Watcher
Newtonian
15.1 kg
SKYWATCHER QUATTRO 250 f/4 is backordered and will ship as soon as it is back in stock.
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.
Specifications
Optical design |
Newtonian reflector |
Objective diameter |
250 mm |
Focal length |
1000 mm |
Focal ratio |
f/4 |
Secondary mirror |
89 mm (minor axis) |
Linear obstruction |
36 % |
Resolving power |
0.48 arc second |
Stellar limiting magnitude |
14.0 |
Max. magnification |
500 x |
Light gathering power |
1276 times the human eye |
Mount attachment |
Tube rings on Vixen style bar |
Focuser |
Crayford dual speed (10:1) |
Tube weight |
15.1 kg |
Tube length |
925 |
Tube diameter |
288 mm |
SKU |
SWP2501-OTA |
In the box
- Newtonian Quattro 250 f/4
- Tube rings on Vixen style bar
- 8x50 finderscope
- 2" tube extension for 2" eyepieces
- 2" to M42 and 2" to 1.25" adapter
- Piggyback 1/4" screw with camera locking nut
- Eyepiece not included