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  • William Optics ZenithStar 71

    Telescope: William Optics ZenithStar 71 - William Optics - ZenithStar 71 ED

    I purchased this telescope new from Agena Astro, it came as a packaged deal including a William Optics f/0.8 Focal Reducer. The price for this package was $558 USD and included free shipping to the CONUS.

    Packing: As I live outside of the United States I received extra packaging to see the telescope on its long journey. All together the telescope arrived packaged inside 4 boxes. The telescope itself comes packaged in some heavy duty "foam" (it's the plastic kind). It's advised to keep this "foam" if you intend to purchase a carry case from William Optics as you are expected to utilise it there since none is supplied with that product.

    General: First impressions of this telescope were all good. The telescope itself is made of machined metal and is SMC coated. The choice to break up the plain colour scheme with anodized metallic colours is tidy and adds a certain "flair" to the design. The inclusion of a temperature gauge as one of the focuser's rotators is inventive. The telescope is deceivingly heavy for its small size, with almost all of the weight in the focuser; meaning the telescope is very back-end heavy. The included retractable dew shield operates smoothly and if pulled back swiftly will actually "pop" the front cover off the telescope indicating an almost airtight seal to the telescope itself.

    Finder Scope: A finder scope is not included with this model from factory however due to its small size it is actually possible to "bore-sight" the telescope. I have been doing this with no real issue.

    Focuser: The included focuser from William Optics is a 2" Rack & Pinion type with a 10:1 dual speed microfocuser. The focuser has 3.2" of travel length and is fully rotatable around 360 degrees. The focus knob on one side of the focuser houses the included temperature gauge; both celcius and farenheit. The other side has the controls for the 10:1 ratio; these are found inside a machined aluminium cover that screws into place. On the underside of the focuser is an adjustable thumb screw to lock the focus into place. There are 2x adjustable tension screws (screwdriver needed) on the topside that are used to adjust tension on the focuser drawtube assembly. The focuser includes an adaptor for 1.25" equipment and operates using brass compression rings rather than locking screws.

    Photography: I purchased this telescope to replace my SCT as my primary imaging telescope. The already fast f/5.9 coupled with the 0.8 reducer brings the final f/ratio down to f/4.72. Images taken so far have produced no noticable Chromatic Aberration and display a field of stars so completely flat it is breathtaking. The FOV is immense and accomodates most targets with plenty of buffering to allow subsequent cropping. The focuser when adjusted to handle the weight of my imaging camera retained focus across an entire night of imaging regardless of changing targets and shifting from one side of the sky to the other. Being able to rotate the focuser 360 degress without causing the focus to shift has its advantages.

    Conclusion: The ZenithStar 71 is a well constructed APOChromatic telescope that delivers exceptional performance for the price and size. William Optics has recently removed the APO descriptor from this telescope based on the feedback of a single customer. While this action shows incredible customer driven focus I believe it to be in error as the many other users and my own observations exhibit no visible chromatic aberration.

    Example Image:

    Target: Messier 42
    ISO: 800
    Exposure: 60s
    Guided?: No and with a poor polar alignment
    Cropped?: No this is an unaltered image

    Attachment 112613
    mirror1 and efredian like this.
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