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919 553-3980



919 553-3980



Thank you for visiting Siebert Optics!

200 Short Johnson Road
Clayton, NC 
USA  27520


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


BT70 RA88 / Miyauchi / Kowa eyepieces


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


Binoviewer Alignment and Supercharge Services


Adapters - Meade Scopes and ETX


Binoculars - Quality Modified


Large and Small Non Illuminated and Illuminated Cross haired eyepieces.


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


Camera Focus Adaptors


Camera Adapters - Universal


H-Alpha Focus Accessories



Special binoviewer services and products you cant get anywhere else 

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





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Saturn Earrings  

Astronomy themed totes/purses


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Astronomy Accessory Links of 

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       by Siebert Optics


Useful Astronomy Links


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Non-Astronomy Items









 45mm. The only ones in their class. Call or email for availablity.

1.3x and other OCA's Click here.

Diagonal Mod

Review links for 2" binoviewer

View 2" Binoviewer Comments
Submit your 2" binoviewer reviews.

 Click on links below to read more Reviews on the 2" Black Night Elite Binoviewers



Cloudy Nights review for the 2 " binoviewers.


Instructions for Diopters style eyepiece holders  low profile 2" to 1.25" adapters

45mm with Double Diopters (Click On Picture)


Click on pictures to enlarge

The 40mm sized up next to one of the biggest and best 1.25" units. 

Click on pictures to enlarge

It is very hard to duplicate the effect you get when you look through a 2" Binoviewer and the 36mm's as seen here but than again the Black Knight was always the one to beat. 



45mm diagonal Modification.  

<Click Picture

This mode is an extra $150 and makes the Echelon and Elite 2" binoviewers interchangeable with a 2" diagonal eyepiece holder similar to the AP Baader with it's T-2 system. The  2" nose piece threads in place for normal use in a dob or unmodified diagonal.


Specifications at a Glance:

2' 45mm CA

Optical Path:  7.25" or 184mm OP

Weight:  1.89 lbs

IPD:  55mm-82mm's

Dielectric Mirrors 99% reflectivity

Optical Windows:  99% transmission

Eyepiece holders:  self-centering Diopter adjustable type.


Pricing Below

Do you want to see what More Clear Aperture can do for your binoviewer. Click here!   

The use of first surface diagonal mirrors will eliminate almost any possibility of reflections that prisms can create and also greatly reduce aberrations. These units have the spec's to outperform any bino in planetary and deepsky use. Try a set of my 2" 34mm or 2" 36mm 70 deg observatory series eyepieces for the ultimate DS view. Low mag correctors in the 1.3x, 1.5x and 1.8x range are available.  Add diopters for fine focusing.   

True 2" binoviewers pricing:


  • 45mm units $1995 All 2" for all scopes (2bino45) 



1.3x OCA for dobs/refractors 38mm CA: $399 (Full illumination down to 2.9)

1.3x / 2x OCA for dobs/refractors 38mm CA: $549 (Full illumination down to 2.9) 

    2x OCA for dobs/refractors (2pc): $299  (Full illumination down to F2.5)


Optical Correctors (OCA's) for True 2" binoviewers pricing:

OCA usage instructions New 38mm CA

OCA usage instructions Old


SCT Accessories pricing:

.6x-.7x FLR for 45mm Elite unit for SCT's: $199

2.5x Low Profile Telenegative  OC   $169 

x2 Low Profile Telenegative  OC :  $169

x3 Low Profile Telenegative  OC :  $169

 Multi Mag OCA for SCT's 0.6x, ******1.3x, ****2.0x, *****2.5x OCA for SCT's: $399* 

Is it a heavy unit? Not in the least. And the Accessories are also light. Add them up and they weigh about as much as a 1.25" setup.



Other Accessories pricing: 

Instructions for Diopters style eyepiece holders  low profile 2" to 1.25" adapters

Lightweight Low Profile Self-centering   2" to 1.25" eyepiece adapters (comes in a set): $60

Click Here for pictures of the special  low profile 2" to 1.25" adapters

Eyepieces for Premium Deepsky Use

2" 34mm or 2" 36mm Observatory Series  (70 deg. fov, 20mm ER):  $458 a set

2" 24mm's Ultra Plus Series Eyepiece  (65 deg. fov, 20mm ER):  $298 a set

Eyepieces for Premium Planetary Use

2" 17mm -19mm's Ultra Plus Series Eyepiece  (70 deg. fov, 20mm ER):  $298 a set

2" 13mm-15mm's Ultra Plus Series Eyepiece  (70 deg. fov, 20mm ER):  $398 a set  


Click Here to see what your Clear Aperture is doing





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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
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available in any dollar amount you wish to purchase.

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