Thorlabs Achromats doublets
 

Which one of these would be the best achromat to get. What should I be lookin for? If you could compare one the century optics.


http://thorlabs.com/NewGroupPage11.c...0&Visual_ID=16 43
-Rh

If you are using a 2" tube, you'll need the 50.8mm diameter size. The focal lengths they list only go as short as 250mm, which may not provide enough magnification. You can try Edmund Optics or it cheaper version, Anchor Optics for 50mm achromatic doublets that are between 75-125mm in focal lenght. Those should be about the right power of magnification.