2" 36mm Eyepiece

  2" has a 70 deg. FOV and 20mm's eye relief.

 Compact in size and only 9 oz.

No "Blacking out" or "Pin Cushioning" 

  2" is $229 (Ob236mm) Brass add $70

35mm Pan vs. Siebert Observatory 36mm. Both are sharp to the edge in fast scopes but the OB wins on pin cushioning and it also has eye relief that people with eye glasses will appreciate. >>>>>>>>>>>>>>>>

All Observatory. eyepieces are under 9 oz.

Were did the Observatory Series eyepieces come from. Click here

Large optics reduce apparent vignetting.

Click on picture to enlarge. Here is the eyepiece comparisons page. 

Observatory eyepieces are known for their excellent edge correction. The 34mm and 36mm are sharp to the edge at f5 and very good at f4.5 without a Paracorr.

2" 34mm Eyepiece  

2" has a 70 deg. fov and 20mm's eye relief.

 Compact in size and only 9 oz.

No "Blacking out" or "Pin Cushioning" 

    2" is $229 (Ob234mm)Brass add $70

All Observatory. eyepieces are under 9 oz.

Large optics reduce apparent vignetting.

Click on picture to enlarge. Here is the eyepiece comparisons page.

Observatory eyepieces are known for their excellent edge correction. The 34mm and 36mm are sharp to the edge at f5 and very good at f4.5 without a Paracorr.

 Observatory Elite

This line has many professional and  amateur applications

See complete list below

Click on pictures below.

 2.7" and 3" 50/70mm

 4"  50mm - 110mm

 4.3"  50mm - 110mm

2.7" 50 -70mm $999 (Brass) add $299  .

All have 25mm E.R.

The 3" 50mm 70 deg FOV

The 3" 55mm 65 deg FOV

The 2.7" 60mm 63 deg FOV

The 2.7" 65mm 60 deg FOV

The 2.7" 70mm 55 deg FOV

3.1lb

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3" 50 -70mm $1199  (Brass) add $399

All have 25mm E.R.

The 3" 50mm 70 deg FOV

The 3" 55mm 70 deg FOV

The 3" 60mm 70 deg FOV

The 3" 65mm 65 deg FOV

The 3" 70mm 60 deg FOV

 3.5lb

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4" 50 -110mm  $1399  (Brass) add $499  4.3lb.

4.3" 65-110mm  $1499  (Brass) add $499  4.3lb.

All have 25mm E.R.

If your scope has to carefully manage focus in-travel please give me details on the limitations of your scopes focus.  

 50mm AFOV 70deg

55mm AFOV 70deg

60mm AFOV 70deg

65mm AFOV 68deg

70mm AFOV 65deg

75mm AFOV 60deg

80mm AFOV 60deg

85mm AFOV 57deg

90mm AFOV 55deg

95mm AFOV 55deg

100mm AFOV 55deg

105mm AFOV 55deg

110mm AFOV 55deg

Observatory Elite 80mm 4 inch eyepieces are 6 element.

 This 80mm 4" eyepiece was sent to the Mount Wilson observatory in 2007 for use in their 60" Cas   See it in use in link below.

All pictures used are with the permission of owner.  http://www.icstars.com/HTML/Events/MtWilson60/index.html Click pictures below.

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How about this 70mm 4.3" 70 deg eyepiece that was sent to the Carnegie Institution of Washington in 2010 for their 6.5 meter or ( 234") Magellan. Link to Observatory below.

http://www.lco.cl/telescopes-information/magellan/instruments/telescopes-information/magellan/

Were did the Observatory Series eyepieces come from. Click here

 This eyepiece come with top and bottom dust caps.

You can get the Optional eyepiece projection camera adaptor. Details below.

 This replaces the top dust cap and has a  2" dia opening and a 2" to 1.25" step-down. This will let you use 2" and 1.25"  format camera setups.(T-2 is also available) So if you want to do eyepiece projection photography, this makes it easy to attach your camera to the eyepiece with little or no additional hardware. This option costs $99

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  2.7" and 3"eyepieces

These 2.7" and 3"eyepieces are for Large and Backyard Observatory Telescopes alike.  Camera adaptor now Optional.

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4 " and + size Eyepieces

The above 80mm is used at the Mount Wilson Observatory in California.  Here  the 80mm Elite is compared to a 40mm Pentax XL.  And below shows the optional mounted on camera adaptor.

The above 70mm 4.3" eyepiece is used in the 24 Foot Dia Magellan in Chile.. picture above. 

This 90mm Elite was sent to Herold Observatory, Onalaska School District, WA as part of an Astro-Physics 4.3" focuser upgrade for their 24" Cassegrain.

Here is the 4.3" Focuser on their site.  Click Here.

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 100mm Elite was sent to South Korea. Scope to be used unknown. More when feedback is available.

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  4.3", 4 ", 3" and 2.7" Eyepieces Some of these eyepieces can even be used in long F.L. backyard Observatory scopes. The eyepieces below will give you at least twice the amount of sky possible for your largest field stop 2" eyepiece.

12" - 60" and much larger Cassegrain scopes.

5" and larger long F.L. refractors.

EX: 6" f15 refractor F.L. 2268mm 1.15deg True FOV. with a 46mm Field stop (41mm Panoptic) Now with the Elite 65mm and it's 72mm F.S.(3" model) now has a 1.63deg True FOV. Now that sounds like only about 40% gain in true FOV but the amount of sky you are now covering is twice the amount sky area. This will hold true for any scope you use. More facts below.

Exit Pupil with 65mm and 70mm at F15 is      = 4.3mm  and 4.6mm

Exit Pupil with 65mm and 70mm at F12.5 is   = 5.2mm  and 5.6mm

Exit Pupil with 65mm and 70mm at F10 is      = 6.5mm  and 7.0mm

Here are some more below.

Exit Pupil with 50mm and 60mm at F15 is      = 3.3mm  and 4.0mm

Exit Pupil with 50mm and 60mm at F12.5 is      = 4.0mm  and 4.8mm

Exit Pupil with 50mm and 60mm at F10 is      = 5.0mm  and 6.0mm

Click on eyepiece pictures below to enlarge.

What scopes can use the 50mm-110mm?  Many CCD chips will benefit from the 40mm-50mm eye lens and huge optics of these eyepieces. In fact it may be the lowest possible power photo you could take through your scope with eyepiece projection imaging. 

 2.7" 3" Diagonals

Level 1

2.7" Diagonals   

3" Diagonals 

2.7" inlet to 3" outlet  

3" inlet to 2.7" outlet  

Black Anodized. $999

++++++++++++++

Level 2a

2.7" Diagonals L2  

3" Diagonals L 2 

2.7" inlet to 3" outlet  L 2

3" inlet to 2.7" outlet  L 2 

Black Anodized. $1999

  T-6 and Black Delrin construction.

++++++++++++++

Level 2b

2.7" Diagonals   

3" Diagonals  

2.7" inlet to 3" outlet  

3" inlet to 2.7" outlet  

Black Anodized. $1999

 T-6 and Black Delrin construction.

L1:  Diagonal are 10th ~ and  99% reflective. Precision Annealed Pyrex.

L2a:  Diagonal are 20th~ and  99% reflective.  Fused Silica for Enhanced Thermal Stability and Scratch Resistants. Black Anodized.

L2b:  Diagonal are 20th~ and  99% reflective.  Zerodur-"Ceramic" for Unmatched Thermal Stability. Black Anodized.

All diagonals are fully and easily  collimatable. 

 All T- 6 and Black Delrin construction, Fully baffled.

60 day return policy. "No restock fees"

Pictures soon to come.

One such project to build an eyepiece for an historic Observatory is describes here below.

In this case I was asked to build the following:

It was thought that the ideal deep sky eyepiece for the Lick Observatory
 36" f19 refractor would be as follows:
>
 116mm focal length (would yield a 6mm exit pupil)
 134mm (5.27") diameter field stop
>
 The above is based on a 60 degree apparent field.  This eyepieces is to have 20mm ER.

The reason such an eyepiece might be needed described below.
>
 The Lick refractor is steeped in history and is the largest
 refractor in daily use today.  Currently they observe with a
 55mm Plossl, which provides only 0.15 degree field.


 This information was based on my conversation. with Alan Adler from the Lick Observatory in Diablo Range east of San Jose, California,

An eyepiece would be needed that would give a .25 deg instead of the .15 deg he was getting with their present eyepiece.

Click to the Lick  website  http://mthamilton.ucolick.org/

Much time and expense was put into the Observatory eyepiece project to help these type of large observatories.      These costs can never be recouped from selling single eyepieces for these specific scopes. Put into other words: You can't make a living on this type of work but here is the good news. 

The time an research that went into the project to create those eyepieces can  be brought into the world of amateur astronomy and applied to the relatively modest scope that are commonly available.

The 2" 34mm, and 36mm Observatory Series eyepieces are the byproducts of this research. These have been scaled down from the original's but this makes them no less significant.

So there's nothing mystical about the name of these eyepieces. In fact the name that has been chosen for this series could not be anymore descriptive of their origin. 

Harry Siebert / Siebert Optics.

Links below

https://sites.google.com/a/onysd.wednet.edu/observatory/

http://www.astro-physics.com/products/accessories/focus_adap/focus_adap.htm#4foc3e