Astronomy Specialist

SKYWATCHER QUATTRO 250 f/4 PRO

$1,399.00

Quantity
- +

 

The SkyWatcher 250 Quattro is a Newton 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 collimable 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 collimable 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.

  

 

Optical design

Newton 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

 

 

  • Newton 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
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