The Infinity 102 is, as the name implies, a 102mm (4”) f/6 achromatic refractor. With a focal ratio of f/6, you’d probably expect there to be some chromatic aberration and indeed you’d be right. Purple or greenish halos are present on the Moon, planets, and stars above around third magnitude. However, the views are surprisingly sharp – I previously thought this scope was terrible on bright targets based on the sample I’d used in the past, but a recent evening with a friend’s unit has proven me wrong.
The scope’s dew shield is hard plastic and isn’t darkened very well. Sanding the interior with rough sandpaper and spray-painting it with an additional coat of flat black will greatly improve image contrast. The edges of the objective lens aren’t blackened at all, but if you’re confident enough to dismantle the lens cell you can blacken them with a Sharpie marker – this will also greatly improve contrast.
The focuser on the Infinity 102 is a 2” rack-and-pinion unit, made mostly out of metal. While it is indeed sturdy enough to hold 2” eyepieces and doesn’t vignette, the scope cannot balance properly in this configuration which makes this feature rather irrelevant.
The Infinity 102 comes with three eyepieces: 26mm (23x), 9mm (67x), and 6.3mm (95x) Modified Achromats – basically Kellners. The 26mm and 9mm work fine, but the 6.3mm is rather uncomfortable to use and not the sharpest. The scope also comes with a 2x Barlow, which is functional, but for optimal high-power views, a 6mm eyepiece like the generic 66-degree FOV “gold-lines” would be better.
Like all of the Meade Infinity scopes, the Infinity 102 comes with a 1.25”, mostly-plastic Amici erecting prism diagonal. This diagonal works okay, but it doesn’t have the highest light transmission, and it produces an annoying diffraction spike on bright objects. It also vignettes with low-power eyepieces including the supplied 26mm MA. A real, standard prism or dielectric mirror star diagonal would be preferable.
Lastly, the Infinity 102 includes a plastic, battery-powered red-dot finder/reflex sight. I don’t like red dot finders for manual telescopes as it is hard to locate deep-sky objects with them, but the wide field of view with the Infinity at low power makes this somewhat less of a problem.
The Infinity AZ Mount
The Infinity mount is somewhat more similar in design to a photo tripod than to a serious astronomical mount. It attaches to the Infinity optical tube using a ¼ 20 screw that threads into a hole in the scope’s Vixen-style dovetail plate, and the altitude pivot point is located below the optical tube rather than on the same plane. This means that the scope is always riding above the center of gravity of the mount, and thus never really balanced. To make matters worse, the scope is slightly rear-heavy even with the stock eyepieces and diagonal – Meade put the dovetail too far towards the front of the scope. As a result, the scope tends to droop when aimed, and you’ll have to tighten the altitude axis quite a bit with a wrench to alleviate this issue.
The Infinity mount uses a lot of plastic parts, but nothing is particularly flimsy and there is metal in most places where it’s needed. There’s also a nice big handle to pan and tilt the scope, a nice added convenience.
Overall the Infinity mount works acceptably well for an entry-level mount. There is some backlash with the slow-motion controls but I’ve seen far more expensive mounts with this problem, and it’s not severe enough to hamper your viewing experience.
For similar prices to the Infinity 102, there are a number of other, superior telescopes you should consider:
- Zhumell Z130 – Significantly larger aperture, better mount and accessories. Does require a table.
- Sky-Watcher Heritage 130P – Significantly larger aperture, extremely portable, better mount and accessories. Does require a table.
- Orion StarBlast 4.5 EQ – Larger aperture, better mount and accessories.
Aftermarket Accessory Recommendations
The main accessory we’d recommend for the Infinity 102 is an upgraded diagonal. The Celestron 1.25” prism is a great bargain, but if you prefer a mirror diagonal and a non-marring compression ring design to securely grip your eyepieces, something like the GSO Dielectric diagonal or Apertura Carbon Dielectric Diagonal would be even better. While Infinity’s focuser could theoretically hold 2” eyepieces, they’ll upset the balance of the telescope and place a lot of strain on the focuser.
A 6mm “gold-line” eyepiece will give you 108x (216x with the included Barlow), and is a lot more comfortable to use than the stock 9mm or 6.3mm eyepieces.
What can you see?
The Infinity 102’s biggest strength is arguably in viewing large open stars clusters like the Beehive or Pleiades, and nebulae such as Orion, the Lagoon, Swan, and Veil (the latter needing dark skies and a nebula filter to be appreciated). It can show you globular clusters too but don’t expect them to be resolved. Some galaxies like M31 and M82 will show dust lanes under decent skies, and M51’s spiral arms can be vaguely glimpsed with pristine, dark skies on a clear night.
Mercury and Venus’ phases are visible with the Infinity 102 – but Mercury’s small angular size and Venus’ thick clouds mean that detail is invisible with any telescope. The Moon looks magnificent. A couple of dark spots on Mars can be seen when it’s near Earth. Jupiter’s cloud belts, Great Red Spot, and 4 moons are easily visible. Saturn’s cloud belts are a bit harder, but the rings and a handful of moons are no trouble to spot. Uranus and Neptune are pale blue dots, difficult to find or even identify with this telescope.
The f/6.5 focal ratio does, as previously mentioned, mean some chromatic aberration is visible on bright targets due to the inexpensive, strongly curved achromatic doublet objective lens. You may or may not notice it on Saturn, and it’s largely avoidable on the Moon, but Jupiter, Mars, and Venus in particular – along with many bright stars – will be surrounded by the ubiquitous purple haze that accompanies many achromatic refractors like the Infinity 102. Whether this bothers you or not is up to the user, but keep in mind that you cannot remove it from the telescope no matter what eyepiece you use.