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Thank you for visiting Siebert Optics!
Serving Large Observatories and the Amateur Astronomy Community alike.

200 Short Johnson Road
Clayton, NC 
USA  27520



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Eyepieces .965" / 1.25" / 2.0" / 2.7" / 3.0" / 4.0" / 4.3"


Large and Small Binocular Cleaning and Alignment services $99 Call or Email for details.


BT70 RA88 / Miyauchi / Kowa eyepieces


Binoviewer Alignment and Supercharge Services


(Specialized Binoviewer services you can't get anywhere else)


Advanced Barlow Lenses including: Modular and 4 element Telecentric magnification multipliers


1.25" and 2" Advanced Binoviewers From $649-$1999


 Binoviewer OCA's and Accessories


Adapters - Meade Scopes and ETX


Binoculars - Quality Modified


Large and Small Non Illuminated and Illuminated Cross haired eyepieces.






Camera Focus Adaptors


Camera Adapters - Universal


H-Alpha Focus Accessories




Special binoviewer services and products you cant get anywhere else 

Also can  >  Click here.   And here.


ICP's Image Correction Prisms for Newts




Extension Tubes


Large refractor modular OTA's


Eyepiece Comparisons


Focal Length Reducers




Planetary Fleece Blanket 


PST Accessories


Telecentric Barlow Lenses


Zero Magnification Adapter





Ladies Corner

Saturn Earrings  

Astronomy themed totes/purses


Free Domain Pictures

Astronomy Accessory Links of 

       products not offered 

       by Siebert Optics


Useful Astronomy Links


International Dealers


Astro photos


Non-Astronomy Items








Welcome to Siebert Optics

     We are filling orders for two 45mm Elite series binoviewers at this time so if you place an order, it may take 2-3 weeks to get to your order. If you order an Echelon or 2" binoviewer it will be added to the list that I am filling over the next few months. If you have any questions about the time frame for a specific order please contact me.

  We do complete alignment and Cleaning services. Short List>>>Apogee / Miyauchi/ Kowa / BT and many other Binoculars. Prices for cleaning and alignment starting at $99       Click here. 

Siebert Observatory Series Eyepieces and Diagonals are being used in the largest visually capable telescopes in the world today. Look and see what these eyepieces can do for your Long Focal length Telescopes. Click here.



Low Power Binoviewer 1.3x OCA's and Power Mag Wheels for all binoviewer


The 25mm Black Night FMC.

Read the info within and you will understand why Nothing even comes close.

Watch this video "Click Here" ---More  "Click Here.".

New Orthos Here Triple-S Series

Click here for the New 2" T-2 modular Barlows.

Supercharge your Stellarvue, Williams Optics and many others like it.

Do you want to share the same high End Binoviewing experience as those who own expensive models from the Big Prism Binos (TV, Denk, Baader) at a fraction of the cost. Do you already own one of the following binoviewers: Williams Optics, Orion, Stellarvue, Burgess, Celestron, Moonfish and Baader 23's etc..... Then you already have what you need to get started. Why pay $900+ For the privilege of using low power wide field EP's  Click here for details.


(Specialized Binoviewer services you can't get anywhere else)

Also Click here.        And here.


Home of quality, affordable Telescope Optics such as Eyepieces, Barlow Lenses, Image erecting prisms,  Diagonals that focus.  Low Power Illuminated Focusable Eyepieces,  Special modified Binoculars. Camera focusing adaptors for all telescopes including the PST.   Adaptors so your filters fit your eyepieces  Adaptors so your Diagonals fit you scopes. and a variety of different size of  high quality Binoviewers and OCA's for all Binoviewers (for comfortable two eye viewing) and  other binoviewer accessories. 

More things of interest Delrin 2" 1.25" T - 2 or T thread End Caps.

Please feel free to check out our site.  If you have any questions, please feel free to ask either via email or phone (1-919-553-3980).  Harry will try to answer any questions you may have as promptly as possibly.  

Click here to go to the OCA and binoviewer corrector page.  

Universal 1.3x and Zero mag OCA's above. This means you can use any binoviewer with little or no magnification added. Always see it here first.  This technology, although similar to the OCS technology, has different characteristics and applications.  

Click Here to go to the PST and H-Alpha bino corrector page.

User Reviews on Black Night Binos

Check out the Elite Series 2" binoviewers.

Siebert Optics 2" Binoviewer 's come standard with self centering compression eyepiece sockets similar to TV and The older BW Optics


 Check out this independent Diagonal calculator if you want too know more about what 

 What Will Binoviewer CLEAR APERTURE will buy you.    

60 day money back guarantee on Black Knight units and accessories.

Gift Certificates are available for any amount you may wish.  Just email or phone and ask how you can obtain one.

Computer Section

Website protection policy.

This site does not pay to have a secure tab in the address line. We protect or customers information by keeping our site simple. We do not have usernames or passwords to input on this site. Our online order forms are on a different system that is secured as you can see in the order form address tab. I police the site regularly for any changes which is a very effective way of protecting the content here.

--Harry Siebert

Page for All OCA's including Low power" correctors for  Baader, Burgess, WO, Stellarvue, Celestron, Orion,  Moonfish,   BC&F, Binomate and the like. More info..


Here is the 2" Ultra barlows similar to the TV powermate.

 Also look at the new modular element barlows for 3 magnifications in one barlow.



Universal Camera adaptors for both 1.25" and 2" focusers and your most demanding applications. These will work with any telescope-camera-eyepiece combination.  



Our 2" Observatory series are unmatched for the price in performance. Edge is flawless at F/5 and even below.




 The Ultra series are the perfect blend of Eye Relief and Wide FOV. Sharp in fast scopes and comfortable to look through. Try one you'll like them.



 Do you need an Inch" Check this out. Zero mag Camera Focus adaptor It will give you 1 inch of focus free of magnification. And help with coma.


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All listed products come with a 30-day money-back guarantee* unless otherwise stated.

Specialty order items are not refundable (items made specifically for you).

We welcome
International orders!.

We accept Visa, Mastercard,


  American Express. U.S. Money Orders, and Personal Checks (held 10 working days for clearing)Online payments may be made securely through