Sharpstar Z4 100mm f/5.5 Sextuplet APO Astrograph
The Sharpstar Z4 is a 100mm aperture, 550mm focal length astrograph built for deep-sky imaging with APS-C cameras such as the ZWO ASI2600MC Pro. Its six-element optical system includes two ED elements. The self-flattening design delivers a corrected 36mm image circle without a separate field flattener.
At 550mm, the Z4 frames targets a little tighter than a 500mm astrograph while retaining a similar f/5.5 focal ratio. Its corrected field covers APS-C sensors. Sharpstar specifies a 36mm image circle, so this model should not be described as a full-frame astrograph.
Key features
- 100mm aperture, 550mm focal length, f/5.5: a useful scale for nebulae, clusters and larger galaxies.
- Self-flattening sextuplet: three optical elements at the front and three at the rear, including two ED elements.
- 36mm corrected image circle: suitable for APS-C imaging, including the ASI2600MC Pro.
- Camera connections: the supplied adapter system includes M82, M68, M54 and M48 options. The M48 adapter provides a thread for a 2-inch mounted filter.
- Precise focusing: rack-and-pinion focuser with fine adjustment and camera rotation for composition.
Specifications
| Aperture | 100mm |
|---|---|
| Focal length | 550mm |
| Focal ratio | f/5.5 |
| Optical design | Six-element air-spaced APO with two ED elements; self-flattening |
| Corrected image circle | 36mm (APS-C compatible) |
| OTA weight | Approximately 4.3kg, excluding mounting hardware |
| Camera adapters | M82, M68, M54 and M48 options |
Imaging-train note: Sharpstar's native self-flattening optical design does not require a separate flattener or a fixed 55mm flattener spacing. Check that your chosen filter drawer and camera adapters fit the available focuser travel. An electronic focuser can be added after checking its mounting kit and coupling on this telescope.
Optical specification: Sharpstar Z4 manufacturer information.
