[ATM] 25x100 binoculars are f/4.5 achromats. Hmmmn?

["stU" <stu@aaronj.com>]

Just thinking out loud here: 

Close to a 25x100 f/4.5 OTA is a 120mm f/5 short tube achromat. 

Wouldn't a pair of used Orion Astroview 120ST's made into binoculars be
something to salivate about? 

Advantages: Bigger aperture. 
Interchangeable EP lenses. 
Better viewing angle with star diagonals. 
Wide range of IPD adjustment 
Choice of correct or astro view. 

Additional parts needed: 2 helical focusers 
2 mirror diagonals 
2 prism diagonals (or 2 mirrors) 
For astro viewing: 2 mirror diagonals. 

Work required: Shorten OTA's to extend back focus. 
Fabricate mount for co-collimation. We can borrow the bi-Newt ideas here. A
center post with orthogonal bearings is the one that I would choose. 



Stu

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