The TS 80mm f/4.4 refractor telescope (named TS-81) is a 6-element FPL-53 astrograph with a diameter of 80mm and a focal length of 352mm
The TS 80/352mm offers a fully corrected field in the focal plane thanks to its 6-element optical system with field corrector (element formed by 2 lenses). Being an Apochromatic telescope (lens with FPL53 glass) with such a corrected field it is a fantastic telescope for astrophotography. In addition the Crayford focuser that incorporates greatly facilitates the task of focusing.
The IMAGING STAR astrograph TS 80mm f/4.4 is therefore an interesting alternative to other established telescopes such as the 80mm Takahashi or the Pentax 75 SDHF. With its slim and elegant finish the APO TS-81 is an ideal portable telescope for deep sky astrophotography in the field. Its length is only 400mm (with the hood retracted). The image quality in the center of the field of view (on the optical axis) is simply perfect and with a very low chromatic aberration, which allows it to be taken to work up to 200x in the field of view.
The APO TS-81 has the following advantages:
-- 80mm diameter, f/4.4
-- O'hara (Japan) FPL-53 triplet objective lens
-- Redesigned 2.5" rack and pinion focuser with double speed at a 1:10 reduction and with thread for camera connection.
-- 42mmm fully illuminated and perfectly corrected field - perfect for sensors up to APS-C format
-- 360° camera rotation for perfect framing
-- CNC machined dovetail
-- Aluminum carrying case with room for accessories
-- Retractable hood: 400mm length with retracted hood
The Crayford 2.5" dual speed focuser with a 1:10 speed ratio allows precise focusing and allows heavy accessories to be positioned in the focal plane without bending or shifting relative to the focus point. The force of 3 radial locking screws is transmitted through a brass ring to distribute the force evenly over the entire circumference. The focuser can be rotated 360º to obtain the framing we are most interested in.
Technical Specifications:
+ Triplet APO air-spaced objective - FPL53 O'Hara glass.
+ Aperture of 80mm with focal length of 352mm (f/4.4).
+ 3-element flattener integrated in an optimal position inside the tube (not on the focuser).
+ Fully multi-coated lens.
+ Tube length with lens hood fully retracted: 400mm.
+ Tube weight: 3Kg (without rings)
+ Aluminum tube and CNC machined rings.
What is supplied with the telescope?
+ APO TS IMAGING STAR 6-element flat field APO telescope with 80mm diameter
+ 2.5" rack and pinion focuser
+ Rigid aluminum carrying case.
+ M48x0.75 adapter with 360º rotation capability
+ CNC machined rings
Optical Test:
Chromatic aberration, on a practical level, is not noticeable. Even at high magnifications, the stars remain completely white.
