Zhumell Z100 Telescope Reviewed – Editor’s Choice

The Z100’s Newtonian Reflector Optics

The Z100 is a 100mm (3.93”) f/4 Newtonian reflector. At such a fast focal ratio, you’d expect there to be some coma, and you’d indeed be right. It’s not noticeable with the stock 17mm and 10mm eyepieces, but with a lower magnification eyepiece like a 25mm Plossl, you’ll start to spot it at the edges of the field of view.

Additionally, at f/4, precise collimation is critical for optimal performance with any reflector. Unfortunately, the folks at Zhumell have declined to offer this crucial feature, and the primary mirror sits in a static, non-collimatable cell. The scope keeps its collimation pretty well over time, which is good, but the lack of adjustments is, to say the least, a bit of a worry. Also, Zhumell won’t be able to help you much if your scope is out of collimation and needs to be replaced or fixed. The Z100’s secondary mirror is collimatable, but you shouldn’t ever need to touch it.

The Z100’s focuser is a 1.25” rack-and-pinion consisting partially of plastic. It works adequately. The scope attaches to its tabletop Dobsonian mount using a short, metal Vixen dovetail.

Decent Accessory Offerings

The Z100 comes with two eyepieces: a 17mm Kellner (24x) and a 10mm Kellner (40x). Even though they don’t have rubber eyecups, which I find annoying, these eyepieces are good. They are made entirely of metal and glass, with no plastic, unlike the eyepieces that come with many cheaper telescopes. The 10mm, however, has a short eye relief, and its short length may cause your nose to bump into the telescope when you look through it.

The scope could theoretically take up to 150-200x, but the mount is a little annoying to use above 100x or so, and the optics max out at around 150x from my experience. 

The most crucial additional accessory we would recommend for this scope would be a 6mm “gold-line” eyepiece or a 2x Barlow lens. The 6mm Goldline gives you 66x magnification, which lets you see planets better than the stock 10mm Kellner, which only gives you 40x. Alternatively, the 2x Barlow coupled with the stock 10mm eyepiece provides 80x. If you can only pick one, we would recommend the 6mm Goldline. But if you’re able to buy both, you could also buy Barlow with the 6mm eyepiece for an astounding 133x, which is about the practical limit of what this telescope can provide.

The Z100 also includes a standard red dot sight, which works just fine for this telescope. 

The Z100’s Tabletop Dobsonian Mount

The Z100 comes on a fairly utilitarian tabletop Dobsonian mount, which it attaches to via a plastic Vixen dovetail saddle. The mount is made mostly of particle board with some sort of laminate glued on, but the azimuth bearings are in fact real Teflon pads. The altitude bearing is not of the conventional Dobsonian design but works nonetheless. Additionally, the mount has a small cutout for use as a handle. 

If you don’t have a sturdy enough table or bar stool to set the Z100 on, the bottom of the mount has a ¼ 20 threaded hole, so you can attach it to most photo tripods. You can also set the scope on the hood of your car, which is arguably a more stable option than a lot of cheap tripods or folding tables.

Alternative Recommendations

If you’re willing to spend more, here are a few of our picks at higher price brackets:

$200-$250

• The Zhumell Z114 has a slightly larger primary mirror of 114mm in aperture – delivering more performance than the Z100 – and a fully adjustable primary mirror for optimum collimation and sharp images, and it’s otherwise very similar.
• The Orion StarBlast II 4.5 EQ shares the optics of the Z114, but it is mounted atop a small equatorial mount and tripod. However, the equatorial mount is significantly less stable than a tabletop Dobsonian and significantly harder to aim or learn how to use.

$250-$350

• The Sky-Watcher Heritage 150P and the smaller 130P both deliver significantly more aperture, and thus better performance, than the Z100 or larger 114mm tabletop reflectors, but in a similarly compact, convenient, and portable package.
• If you cannot get ahold of a Zhumell Z114, the Orion StarBlast 4.5 Astro is almost identical, but is priced much higher and thus isn’t really a good deal.
• The Popular Science by Celestron StarSense Explorer DX 100AZ offers similar performance to the Z100 but with refracting optics, a full-sized tripod, and the assistance of Celestron’s StarSense Explorer technology in finding targets.

Aftermarket Accessory Recommendations

The f/4 focal ratio of the Z100 prevents the use of a 25mm or 32mm Plossl for wider fields of view. A 6mm “gold-line” will provide 67x. For even more magnification, you could add a 2x Barlow lens to get 80x with the included 10mm and 133x with the 6mm goldline, which are pretty decent magnifications for lunar or planetary viewing with a telescope of the Z100’s size and capabilities. But besides an extra eyepiece and/or barlow, we wouldn’t suggest buying more accessories for the Z100 instead of just getting a bigger telescope like the Z114 or Z130.

What can you see with the Zhumell Z100?

The Z100 will offer great views of the Moon and decent views of Venus, Mars, Jupiter, and Saturn. Venus will show its phases, Mars its ice caps and maybe a few dark areas at opposition, and Jupiter and Saturn will show their moons and cloud belts. Jupiter’s Great Red Spot is also visible, as are Saturn’s majestic rings and the gap between them known as the Cassini Division. Uranus and Neptune are also visible as tiny bluish dots, but they are a bit tricky to locate. 

A small, inexpensive refractor may do a slightly better job on the planets than the Z100, but the Z100’s larger aperture makes it superior for viewing deep-sky objects, and it’s also far more lightweight, compact, and portable than a refractor.

Outside the solar system, the Z100 can show you thousands of double stars and hundreds of open star clusters. You’ll be able to spot globular clusters as fuzzy smudges, a few dozen of the brightest galaxies, and, with luck, maybe pick out hints of detail in a few, such as the dust lanes in M82 or M31. However, doing this will require dark skies. The Zhumell Z100 is also capable of showing various bright nebulae like Orion, the Lagoon, the Dumbbell, and the Ring, which will look great even from light-polluted skies.