Askar 140APO f/7 Triplet

140mm f/7 Triplet APO Optics with ED Glass

The optical system is built around a 140mm air-spaced triplet objective lens. It includes one extra-low dispersion (ED) glass element; the Askar APO series uses special optical designs and multiple elements to correct chromatic aberration for better detail and color accuracy.

The native 980mm focal length at f/7 strikes a versatile balance between wide-field views of large targets and the image scale needed to resolve fine detail on planets and smaller galaxies. The 140mm aperture gives an inherent advantage in light-gathering power, resolution, brightness and contrast.

Optional Correctors for a 44mm Flat Field

For flat-field imaging, Askar offers two optional accessories for the 140APO, each supporting a 44mm full-frame image circle.

• 1x Flattener: This triplet keeps 980mm at f/7 and corrects field curvature and coma, for flatter field edges and finer star points. It comes with M68, M54 and M48 adapters.
• 0.8x Reducer/Flattener: This triplet reducer with field flattening gives 784mm at f/5.6, for a wider field and shorter exposures (the same exposure takes 64% of the time needed at f/7). It comes with M54 and M48 adapters.

Both screw into the 140APO after the 2" and 1.25" adapters are removed, give a standard 55mm back focus from the base of the M48 male thread, and have a built-in 2" filter thread.

125mm Retractable Tube for Binoviewer Flexibility

A key mechanical feature of the 140APO is its 125mm retractable rear lens tube. The design is strengthened so the optical axis is not affected when the tube is stretched, and a rudder-type locking ring makes it easy to loosen or tighten.

With the tube contracted, the 140APO can be used with a binoviewer for visual observation. With it stretched, it takes the specific reducer or flattener for imaging, or a diagonal and eyepiece.

3.5" Rack & Pinion Focuser with 100mm of Travel

The Askar 140APO has a CNC-machined dual-speed 3.5" rigid rack-and-pinion focuser with a 1:10 fine adjustment and 100mm of travel. Laser-engraved scales in the length and circumference directions help with adjustment and recording, and it is compatible with most motorized focusers.

A big 360° rotator with precise scales lets you frame your target, and an enlarged locking screw prevents image shifting during shooting. Two finder bases sit on both sides of the focuser.

A 10.9kg System with a 300mm Losmandy Plate

The 140APO was designed with portability in mind. The OTA weighs 9.2kg and is 735mm long with the dew shield contracted, 870mm stretched. The inside of the main tube has matting paint and an internal baffle.

The 300mm standard Losmandy-style dovetail plate has multiple holes for adjusting ring position, which makes balancing easier. The 1.7kg tube rings open and lock with CNC thumb screws and have a heightened base, and the 220mm handle features an integrated slot, allowing it to double as a mounting base for a finder or guide scope. The total weight of the scope with rings, handle, and plate is 10.9kg.