Askar Sharpstar Z4 100mm f/5.5 6-element flat field apochromat

Askar Sharpstar Z4 100mm f/5.5 6-element flat field apochromat

This telescope is ideal for capturing stunning wide-angle deep sky images with an image circle of 36mm (APS-C).
♦ Sextuplet refractor with 100mm aperture and focal ratio of f/5.5

♦ Flat field of view over a 36 mm image circle

♦ Two ED elements almost completely eliminate chromatic aberration

♦ 3.4" rotating focuser with gear reduction, M90-M54 and multiple thread adapters, 2" adapter ring

♦ Fixed back focus - when the image is in focus, it is also best corrected.

♦ Transport length 482 mm, weight 4.3 kg

♦ Includes tube ring, Vixen standard dovetail bar, carrying handle, finder shoe and hard case

♦ Quality guarantee from TS: Each APO is individually checked (cosmetically, mechanically and optically) before shipping and delivered with a complete checklist




Askar Sharpstar Z4 100mm f/5.5 6-element flat field apo
To meet the needs of users and the market, Sharpstar has launched an integrated astrograph: the Z4. It has an aperture of 100mm and a focal ratio of f/5.5. The Z4 is a sextuplet astrograph with three front lenses and three rear lenses, with two lenses being ED glass.

Like other series of Sharpstar astrographs, the Z4 is designed to self-flatten the field of view, eliminating the need for back focus calculations. You can easily bring the subject into focus and the optical system is perfectly tuned for imaging. It is ideal for capturing stunning deep-sky wide-angle shots over a 36mm image circle (APS-C).

For the price, this fast apochromatic telescope offers excellent value and can match the performance of telescopes costing three or four times as much. This is especially true when paired with astronomy cameras with smaller 1" and 4/3" sensors, while the Z4 is not recommended for use with full frame cameras.

The appearance of the Z4 breaks the previous style of the Sharpstar with its matte gray finish. The light gray tube and the dark gray focuser and tube ring give the astrograph a calm but dynamic look. The pipe clamp has a handle on the top, easy to hold and mount. The handle is designed as a bracket for attaching a viewfinder base, etc.

The entire tube has a length of only 482 mm with the dew cap retracted. He weighs 4.3 kg. This astrograph has a flange flange of 55mm so standard M48 rings work well when using DSLR cameras and you can use astronomical cameras with accessories.

The Z4 features a large 3.4" focuser with a 1:10 fine adjustment knob and a 360° rotator for easy focus and angle adjustment. It has M86, M68, M54 and M48 adapters, with the M48 adapter has an internal thread into which 2" filters can be inserted.

A 300mm Vixen standard dovetail bar makes balancing on the equatorial mount easier.




Lens: Sextupletapo with air gaps (including two ED glasses)
Opening: 100mm
Aperture ratio: f/5.5
Image Circle: 36mm
Focuser: 3.4" rack and pinion focuser with reduction
Back focus/working distance: 55 mm from the M48 thread
Rear end thread: M48x0.75 male thread
Adapter: M86x1-M68x1, M68x1-M54x0.75, M54x0.75-M54x0.75, M54x0.75-M48x0.75 (with filter thread M48x0.75)
Dew Shield: Retractable
Total length: 482mm
Net Weight: 4.3kg
Gross weight: 5.6 kg without the aluminum case


♦ Telescope
♦ Standard finder shoe
♦ Pipe clamp
♦ Prism rail (Vixen standard)
♦ Handle
♦ 4 piece photographic adapter
♦ Warranty card
♦ User Manual
♦ Hard case