Askar Sharpstar Z4 100 mm f/5.5 6-Element Flatfield Apo

Askar Sharpstar Z4 100 mm f/5.5 6-Element Flatfield Apo

According to the users´ and market demands, Sharpstar has launched an integrated astrograph - Z4. It has an aperture of 100 mm and the focal ratio is f/5.5. Z4 is a sextuplet astrograph with three pieces of lens at the front and three pieces at the back, and two of them are ED glasses.

Just like other series of Sharpstar astrographs, Z4 is designed as self-flattened so there is no need to calculate the back focus. You can just make the target stay at the focus, and the optical system is perfect for imaging. It is ideal for capturing stunning wide-field images of the deep sky over a 36 mm (APS-C) image circle.

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

The appearance of Z4 breaks through the previous style of Sharpstar with its matte gray coating. Light gray lens tube plus dark gray focuser and tube ring, make the astrograph looks calm but vibrant. The tube ring has a handle on the top which is easy to carry and assemble. The handle is designed as a slot on which you can mount a finder base, etc.

The entire tube has a length of just 482 mm with the dew shield retracted. It weighs 4.3 kg. This astrograph has the back focus of 55 mm, so common M48-rings will work fine when using DSLR cameras and you can use astronomical cameras with accessories.

Z4 uses a large 3.4" focuser with a 1:10 fine adjustment knob and a 360° rotator for easy focusing and angle adjustment. It has M86, M68, M54, M48 adapters, and the M48 one has an internal thread that can fit 2" filters.

A 300 mm Vixen-style dovetail plate makes it easier to balance on the equatorial mount.

Astrophotographic results obtained with this telescope on Astrobin

Here you can find some astrophotographs made with this telescope model: Link to Astrobin

Astrophotographic results obtained with this telescope on Astrobin

Here you can find some astrophotographs made with this telescope model: Link to Astrobin