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Kokusai Kohki 1.25" Fujiyama HD-OR Orthoscopic Eyepiece (Japan) - 4mm

5.0 (3 Reviews) Read Reviews Write Review
Brand Kokusai Kohki
Part Number HD-OR 4mm
Availability available

Product Info

Manufacturer Description

Kokusai Kohki continues the tradition of offering the highest quality Japanese made Orthoscopic eyepieces with the introduction of their brand new FUJIYAMA HD-OR eyepiece lineup. Fujiyama HD-ORs are hand crafted at their Tokyo factory and individually inspected before shipping.

Named after the Japanese name for that sky reaching symbol of Japan - Mt. Fuji - the FUJIYAMA HD-ORs come standard with multicoatings on all air to glass surfaces (cemented lens surfaces are uncoated), giving them extended light throughput, and brighter images overall, as compared to Kokusai Kohki's previous volcano-top OR eyepiece lineup. And all lenses are edge blackened to reduce internal light scatter and reflections to an absolute minimum.

The entire Fujiyama lineup is parfocal, accepts standard 1.25" astronomy filters, and comes with plastic eyepiece caps. The chrome barrels of the Fujiyama HD-ORs are smooth-sided, and they have removed the helpful, but also often annoying, safety groove.

Solid construction, bright, clean and sharp views throughout a fully corrected 42 degree AFOV with sharp field stops makes the Fujiyamas perfect for every type of viewing. They are also an exellent match with high end apochromats for hard core planetary, lunar, solar and double star viewing.

Each eyepiece carries a one year Kokusai Kohki parts and labor warranty.

Reviews

5.0 (Based on 3 Reviews) 100% of reviewers recommended this product.
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    1. Mmac54

      Mmac54 Active Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by Mark M.
      1516758462
      Jan 23, 2018

      5.0 KK Orthos 4mm. 6mm

      Pros:

      Cons:

      Comments:

      I have nearly a complete set of these KK orthos. I use them in a 60mm f15 achro, an 80mm f6 Apo, a 127mm f7.5 Apo and a 100mm ED f9 . I have hign contrast views. Of course I tend to use the longer focal length eyepieces more. But I want to be able to use the four in the six when the skies permit matched with the appropriate telescope. I am very satisfied with the service I have received from this vendor. This is the second or third time I have purchased from them. I will purchase again.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    2. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by JimOfOakCreek of Oak Creek, WI.
      1412380800
      Oct 3, 2014

      5.0 There is no eyepiece that is sharper.

      Pros:

      Razor Sharp,Cool White Presentation,Maximum Light Throughput,Lightweight,Quality Lenses

      Cons:

      43 Degree Fov,Short eye relief

      Comments:

      Agena shipped the 4mm, 6mm and 25mm to my door in the MidWest in two days. These eye pieces are as sharp as money can buy. Their simple design means they have high light throughput due to fewer glass elements. I like the cool white, bright presentation. Solid high quality construction.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    3. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by John of Tucson, AZ.
      1393891200
      Mar 3, 2014

      5.0 Excellent orthoscopic

      Pros:

      Strong Construction,Lightweight,Quality Lenses,Easy to Use

      Cons:

      Comments:

      Well constructed eyepiece and is as described by manufacturer. Observed Jupiter - superb with moons showing disks. Observed Trapezium and observed all companions (a - f). Observations made with FS 152 mm f/8 Takahashi.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

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      Specifications

      Apparent Field of View 42°
      Barrel Size 1.25" (31.7mm)
      Bolt Case Included Yes - Free Agena Eyepiece Container
      Bolt Case Size Agena 37x60mm
      Coatings Multi-Coated
      Design Abbe Orthoscopic
      Height (without Eye Guard) 1.50" (38.0mm) To be updated
      Max Width 1.34" (34.0mm) To be updated
      End Caps 2
      Eye Lens Diameter 0.16" (4.0mm)
      Eye Relief by Design 3.4mm
      Field Stop Diameter 2.6mm
      Filter Threads Standard 1.25" Filter Thread (M28.5 x 0.6)
      Focal Length 4mm
      Lens Elements 4
      Lens Groups 2
      Parfocal Yes
      Rubber Eye Guard No
      Blackened Lens Edges Yes
      Manufacturer Kokusai Kohki
      Eyepiece Focal Length 5mm and Under
      Eyepiece Field of View Up to 50 degrees
      Eyepiece Series KK Fujiyama HD Ortho
      Barrel Type Smooth sided