Is it possible to build a triplet apochromatic refractor?

[Chris]

1 hour ago, Chriske said:

Woow...! Al these surfaces without coatings.....'Some' light is going to bounce back and forth in that cell imho.  You'll loose contrast, a lot of it.
These early astronomers had no coatings because the technique wasn't available yet. Otherwise they surely would have applied.

I'm guessing it wouldn't hurt to have an extra long flocked due shield, long flocked baffled tube, and slow f-ratio to help off set the lack of coatings.

p.s. Sorry Fishie for jumping on your thread. Any thoughts on which direction you'll go with your project?