TEC APO140 f/7 Fluorite Apochromatic Telescope

The TEC APO 140FL f/7 is a 140 mm apochromatic refractor designed for both visual observing and CCD imaging. With a 980 mm focal length and f/7 focal ratio, it provides a combination of aperture and image scale suited to a broad range of astronomical targets.

The objective is an oil-spaced apochromatic triplet with a central calcium-fluorite (CaF₂) element. TEC states that the optical design provides colour correction optimised for both visual use and imaging. Multi-layer coatings are applied to all objective surfaces to maximise light transmission.

The objective is housed in an aluminium cell, while the optical assembly sits in a lightweight aluminium tube with an anti-reflective interior treatment and sharp-edged internal baffles. TEC also states that no collimation adjustment is required after the telescope leaves the factory.

Focusing is handled by a 3.5-inch Starlight Instruments Feather Touch 3545 focuser developed in collaboration with TEC. It provides coarse and fine focusing through a 9:1 planetary reduction assembly, together with a rotating focuser and a 2-inch locking metal collet designed to maintain precise and concentric camera or eyepiece positioning.

For astrophotography, the APO 140FL can be fitted with TEC’s optional focal reducer-corrector. This reduces the focal ratio from f/7 to f/6.2 and provides a 115 mm back focus, giving a wider field and faster imaging configuration.

The telescope uses a 150 mm diameter aluminium tube with a dew shield extending the overall length to 1050 mm. With the dew shield retracted, the tube length is 840 mm. TEC specifies an optical-tube weight of 8.2 kg and a configured weight of 9.5 kg including rings, plate, handle and finder.

The APO 140FL f/7 is therefore a versatile high-aperture refractor for observers who want a telescope capable of both detailed visual observation and serious astrophotography, without being designed exclusively around either application.