Eridanus Optics CC
Postal Address PO Box 100148
  Moreleta Plaza
Cell 083 632 4894
Fax 086 636 2283
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What's New?
Now in stock
1. Green Laser Pointers
2. Orion 2” 13% Moon Filters
3. LASER Collimator
4. 2x Barlow lens (1¼”)
Eridanus Optics CC can supply zoom eyepieces from manufacturers such as Orion, Vixen and William Optics.   Contact us if you are interested in one of these products.
To design and manufacture zoom eyepieces can be challenging and compromises are sometimes inevitable.  You may therefore get better performance (image quality) from a single eyepiece than from a similarly priced zoom eyepiece.  The following benefits of zoom eyepieces should however be considered:
  • You only use one eyepiece for all of your viewing.  This is particularly useful when you have an audience and want to show them several objects of different sizes (e.g.:  the Moon, a lunar crater, an open cluster, a double star, etc).  All these objects can be viewed at an optimum magnification that frames the target nicely and that reveals the most detail for the viewing conditions without making a single eyepiece change.
  • Relocating your target when it drifts out of view is a breeze.  Simply zoom out and centre your target again.  Once the target has been relocated, you can zoom in again to an appropriate setting.  No need to go back to the viewfinder.
  • Lots of time is wasted in changing eyepieces, reducing your viewing time dramatically.  You can therefore view more objects during the same viewing session.
  • The eye relief in most quality zoom eyepieces is superior to those of similar short focal length fixed eyepieces.
  • You would have to be an exceptional amateur astronomer to see the reduced quality of a zoom eyepiece when compared to a fixed eyepiece of the same price.  Image quality is in most cases more degraded by light pollution, atmospheric conditions, eyesight and other effects rather than by the quality of the eyepiece.
  • One quality zoom eyepiece will cost you less than a range of quality eyepieces with fixed focal lengths.

Eridanus Optics CC can supply the following zoom eyepieces:

William Optics

 8mm to 24 mm Zoom

  • 40 to 60 apparent field of view 

  • 20mm eye relief

  • Fully multicoated

  • 1 barrel

  • Threaded for filters

  • Adjustable puch-up eyecup


7.5mm to 22.5mm High Quality Zoom
  • 42 to 66 Apparent field of view
  • 18 to 20mm eye relief
  • Fully multicoated
  • 1 barrel

  • Threaded for filters

  • Reduced chromatic aberration

  • Adjustable puch-up eyecup

Baader Planetarium
8mm to 24mm Hyperion Zoom eyepiece for low power to medium power observing:
  • Apparent Field of View = 50 at 24mm and 68 at 8mm
  • Eye relief = 15-19mm
  • Phantom group coated (Incredibly low losses).
  • 1 and 2" interchangeable barrels

  • Threaded for filters and cameras

  • Crisp images right to the edge at all magnifications

  • Adjustable puch-up eyecup

8mm to 24mm Premium Zoom eyepiece for low power to medium power observing:
  • Apparent Field of View = 40 at 24mm and 60 at 8mm
  • Eye relief = 15-19mm
  • Fully multicoated surfaces.
  • 1 barrel

  • Threaded for filters