Askar Sharpstar Z4 100mm f/5.5 Apo 6-element flat-field astrograph
In accordance with user and market demands, Sharpstar has released an integrated astrograph: the 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 lenses at the front and three pieces at the back, and two of them are ED glasses.
Like other Sharpstar astrograph series, the Z4 is designed to be self-aiming, so there is no need to calculate back focus. You can make the lens stay in focus and the optical system is perfect for imaging. It is ideal for capturing stunning wide-field images of the deep sky in a 36 mm (APS-C) image circle.
For the price, this fast apochromatic telescope offers excellent value for money and can approach the performance of telescopes costing three to four times as much. This is especially true when paired with astronomical cameras with smaller 1" and 4/3" sensors, but use of the Z4 with full-frame cameras is not recommended.
The appearance of the Z4 breaks from Sharpstar's previous styling with its matte gray coating. The light gray lens tube plus the dark gray focuser and tube ring make the astrograph look quiet but vibrant. The tube ring has a handle at the top that is easy to carry and mount. The handle is designed as a slot in which a finder base, etc. can be mounted.
The entire tube is only 482 mm long with the spray guard retracted. It weighs 4.3 kg. This astrograph has a 55 mm back focus, so common M48 rings will work well when using DSLR cameras and astronomical cameras can be used with accessories.
Z4 uses a large 3.4" focuser with a 1:10 fine adjustment knob and 360° rotator for easy focusing and angle adjustment. It has M86, M68, M54, M48 adapters, and the M48 has an internal thread that can fit 2" filters.
A 300mm Vixen style dovetail plate makes it easy to balance on the equatorial mount.
| Objective lens: |
Apo sextillion fully spaced in the air (including two glasses for erectile dysfunction) |
| Aperture: |
100 millimeters |
| Focal ratio: |
f/5.5 |
| Image circle: |
36mm |
| Focuser: |
3.4" rack and pinion, dual speed |
| Rear focus: |
55mm from M48 thread |
| Rear thread: |
Male thread M48x0.75 |
| Adapters: |
M86x1-M68x1, M68x1-M54x0.75, M54x0.75-M54x0.75, M54x0.75-M48x0.75 (with M48x0.75 filter thread) |
| Lenscover: |
Retractable |
| Total length: |
482 millimeters |
| Net weight: |
4.3 kilograms |
| Gross weight: |
5.6 kg without aluminum case |
Supplied with:
Telescope
Standard finder shoe
tube ring
Dovetail plate (style Vixen)
Handle
4-piece photographic adapter
Warranty card
Manual
Hard case
