11
Specifications
Telescope specifications
Optical Design
Refractor (air-spaced triplet APO)
Field Flattener
Thread-on (2 lenses)
Aperture (mm)
150 mm (5.9 in)
Focal Length
1050 mm (41 in)
Focal Ratio
7
Finderscope
9x50, erect-image, right-angle
Diagonal
2" dielectric coatings
Tube Rings
With 3" (D Style) dovetail plate
Highest Useful Magnification
354 x
Lowest Useful Magnification
21 x
Limiting Stellar Magnitude
13.4
Resolution (Rayleigh)
0.93 arc seconds
Resolution (Dawes)
0.77 arc seconds
Light Gathering Power (Compared to Human Eye)
459 x
Optical Coatings
Fully multi-coated
Fully Illuminated Field With Field Flattener
44 mm (1.7 in)
Optical Tube Length (Retracted Dew Cap)
92 cm (36 in)
Optical Tube Weight
15 kg (32 lbs)
Telescope Visual Backfocus
∗
>170mm (6.7 in)
Field Flattener Backfocus
**
96mm (3.8 in)
Threads specifications
Rings/
Threads
Focuser
Tube
Drawtube
Adatpor
Field
Flattener
DSLRl
Ext. Tube
Enlarged
T-Ring
In
Ø
n/a
M74x1 F.
M65x1 F.
M62x1 F.
M48x0.75 F.
In screw depth
n/a
7 mm
7.5 mm
8.5 mm
variable
Out
Ø
M74 x1 M
M65x1 M.
M62x1 M.
M48x0.75 M
Camera
Out screw depth
6 mm
6 mm
6 mm
6 mm
n/a
∗
The visual back focus of the telescope is the distance from the end of the focuser tube (with 2’’ adapter
installed) to the focal plane. This means, all accessories needing 170mm back focus or less can be installed.
**
The back focus of the field flattener is the distance from the back of the field flattener (flat surface at the exit)
to the focal plane. To obtain flat wide field images, the sensor should be positioned at exactly (+-1mm) this
distance. See also detailed explanations on bottom of page 8.
