Kson Eyepiece – 1.25″ Orthoscopic, 4 Element 4.5mm LE (Long Eye Relief)


Only 1 left in stock


Classic Abbe Ortho Eyepiece – Now the LE version has even better eye relief!

How good are they exactly? 

“This eyepiece line is within the following competition class of eyepieces with similar specifications and performance: …Masuyama Orthoscopic, Meade Research Grade Ortho, Meade Series II Orthoscopic, Nikon Ortho, Siebert Optics Star Splitter/Super Star Splitter, Takahashi Ortho, Telescope Service Ortho, Unitron Ortho, University Optics HD Orthoscopic, University Optics Abbe Volcano Orthoscopic…” – Paolini, W. (2013) Choosing and Using Astronomical Eyepieces. Springer : New York, p.289

TLDR: They compare extremely well even to premium brands.  In fact. Kson make these for several other brands who slap their labels on them. They are that good.

Detailed Specifications:

  • 43 Degree Apparent AFOV
  • 8mm eye relief
  • Field Stop 4.1
  • 4/2 Design Elements/Grp
  • Coatings: FMC
  • 1.25″ Barrel


Focal length Barrel Size F.O.V   (°) Coatings Eye Relief         (mm) Field Stop        (mm) Eye Lens OD (mm) Weight               (g) Eye Cup
F4.5mm .1.25″ 43 M/C + edges 8 ø4.1 5 40.2 Fold-down
F7.5mm .1.25″ 47 M/C + edges 9 ø6.2 8 46.2 Fold-down
F10.5mm .1.25″ 46 M/C + edges 10 ø8.5 10.6 52.4 Fold-down


  • Superb High-contrast Planetary Eyepieces
  • Amazing Lack of Distortion
  • Consistent, Solid Performers
  • Solid design
  • They work with all telescopes, but do particularly well with slower (f/7+) telescopes
  • Includes quality hard plastic screw case (note eyepiece shown in pic 2 is not the eyepiece, it’s there to show the case) (simply twist and unlock), plus box.
  • Soft rubber eyecup for pleasant viewing comfort
  • These eyepieces are Fully-Multi-Coated
  • These have have a blackened, metal interior to maximise contrast and light transmission to the eye

As Kson’s Australian Authorised Dealer, we have the full LE range of these eyepieces available, 4.5, 7.5, 10.5 as well as the 16.8 and 24mm.  See our other listings.

Reviewed 7/7/19: This eyepiece was reviewed by the SRAA (Scenic Rim Astronomy Association) and is very suitable for scopes of f/4.7 and slower (e.g. f/5, f/6 etc..), especially on planets like Saturn.  You’ll love it!

Customer Feedback on these eyepieces:

I managed to put the Kson eyepieces through their paces. Jupiter and Saturn were very visible and using the Kson gear in my C90 Mak the results were, eventually, eye-popping. I say eventually because I found that achieving focus was a tad finicky but once I got the hang of the subtleties it was all systems go. I found the 10.5mm produced lovely clear images which were replicated through the 7.7mm. Using a 2x Barlow with the 10.5mm was right on the edge of overpowering the Mak, after all it was x240, but when seeing conditions were good it delivered. At one stage I barlowed the 7.7mm but it was a bit much so I modified the Barlow back to x1.5 with stunning results – crisp to the edges. 

The highlight came on Monday night around 2230 when, thanks to the Sky and Telescope website, I managed to get a fairly clear bead on Jupiter’s Great Red Spot (more brown than red). A couple of nights later I concentrated on Saturn and actually discerned some separation, only just, of the Cassini Rings. It’s all well and good to read of such things and see photographs of them but to behold them with your own peepers is very special. Once again many thanks for your advice and excellent customer service.” – Randall

Additional information

Weight .075 kg
Dimensions 15 × 13 × 11 cm


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