A new telescope: William Optics Megrez 90

I’ve been really quiet with the astronomy-related blog posts over the past year, but that doesn’t mean that I’ve been straying from the hobby of amateur astronomy – far from it. I’ve signed up with two local clubs and have been brining my scopes out to star parties (or just my back yard) whenever I can.

Up until recently my only two telescopes have been a Orion XT10i, a 10″ dobsonian, and a Coronado PST for viewing the Sun in Hydrogen-alpha wavelengths. This past holiday I treated myself to a new scope, a 90mm apochromatic doublet refractor made by William Optics (WO) named the Megrez 90.


The Megrez 90, as the name implies, is a high-quality refractor telescope that uses calcium fluoride optics. The objective lens is 90mm in diameter and the scope has a focal length of 621mm, which means it has a focal ratio of f/6.9. When WO brought this scope to market, it took it by storm as it was quickly regarded as a high quality instrument at an astonishingly low price, easily comparable in optical quality, fit and finish to long-standing fonts of quality such as TeleVue and Stellarvue.


I found the reviewers to be spot-on with their assessment of this telescope’s construction and features. Its dual-speed (10:1) Crayford-style focuser has made me wish I had it on my big Orion XT10i. The stars are beautiful pinpoints with no detectable (to me at least) chromatic aberration. I have only spent a few nights outside with this ‘scope so I don’t have a full feel of its capabilities… more on that later. But I will say that I have been impressed so far and would at least offer it as a suggestion to anyone who is looking for a telescope in its class.

Along with the telescope, I purchased WO’s EZTouch alt/az mount and wooden surveyor’s style tripod to put it on, as well as their Red Dot Finder instead of a classic finder scope. I found with my XT10i+Telerad that I prefer to star-hop to my target rather than bungle around inside a restricted FOV.


I foresee many nights out under clear skies with this fine instrument.

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