Harpers Photographic

The Messier R-90 is a great instrument to start taking astronomy seriously. The 90mm aperture delivers 200 times more light than the human eye! Observe craters, mountain ranges and rills on the surface of the moon, the rings of Saturn and the surface detail of the great gas giant Jupiter. Supplied with 10mm, 12.5mm and 25mm Plossl eyepieces.

Specification

Achromatic Refractor
Yea
(Optical Type)
Focal Length
800mm
(Focal length in mm)
Aperture
90mm
(Primary lens or mirror diameter in mm)
Weight
12.25kg
(Weight of telescope in kg.)
Brightness
130
(Light transmission factor)
PC Occular compatible
Yes
(Suitable for use with an elecronic eyepiece)
EQ Mount
Yes
(Equatorial mount)
MON1 Mount
Yes
(Equatorial Mount 1)
Motor Drive Motor Drive Compat
Yes
(Tracking motor available)
Resolving Power
1.53
(Resolving power in arc-seconds)
Focal Ratio
1:10
(Focal ratio)
Eyepiece Fitting
1.25"
(Eyepiece diameter in inches)
Stars Visible up to Magnitude
11.5
(Ability of telescope to resolve faint stars)
Viewfinder
6x30
(Type of viewfinder)
Magnification
36x-200x
(Range of magnifications with eyepieces supplied)
Maximum Magnification
140x
(Maximum meaningful magnification of the telescope)
Tripod
Yes
(Tripod included with telescope)