Sky-Watcher Heritage 100P

Worth knowing before you buy

How well-collimated does the Z100/Heritage 100P arrive from the factory?

The scope arrived well-collimated despite shipping from overseas—one owner found the secondary mirror offset was visible but the primary and secondary were properly centered relative to each other when checked with a sight tube. No collimation adjustments were needed out of the box, though the primary cell is glued and non-adjustable, limiting future collimation options.

What eyepieces should I buy beyond the included kit?

The bundled 17mm and 10mm Kellner eyepieces have very tight eye relief and perform poorly on the fast f/4 optics due to coma and astigmatism at the edges. Members recommend adding orthoscopic, Plossl, or premium wide-angle eyepieces like Erfle designs; a 4mm orthoscopic and 20mm Plossl were specifically praised for sharpness and usability.

Is the plastic focuser and plastic dovetail clamp a reliability issue?

Owners reported the low-profile plastic Synta focuser works smoothly without focus shift issues, even with dedicated oculars and barlows reaching down to 3.6mm equivalent.

Can I use low-power, wide-field eyepieces like a 40mm?

A 40mm eyepiece can reach focus with the scope's low-profile focuser, though the 10mm exit pupil exceeds typical dark-adapted pupils (around 7–8mm), causing slight light loss. A 20mm or 25mm would be more practical for the f/4 focal length, producing a 4–5mm exit pupil and better eye comfort.

How does the optics quality compare to larger 6-inch f/5 scopes?

The 4-inch optics are noticeably sharper and more impressive than expected for the aperture; one owner with a 6-inch f/5 found the Z100's optical quality very competitive on small details like the Trapezium stars, though the larger scope wins on brightness and deep-sky faintness. The f/4 parabolic mirror appears to be genuinely well-figured despite the entry-level price.

What modifications do owners typically make?

Common upgrades include replacing the spider vanes (original ones are thick plastic and produce diffraction), flocking the tube interior, and center-spotting the primary mirror. One owner added a collimatable primary cell despite the original being glued.