Which Barlow?

Which Barlow would you recommend for smaller Newtonian scopes in the 4 to 6 inch range and why?

IME stay above the budget priced ones.

Televue, Celestron Ultima, UO or Vixen are some examples of well built and coated units that really will not degrade the image. Siebert also. A barlow adds 2 or 3 (or more) extra glass elements to the optics. It costs a little more to do this right.

My apologies for stating the obvious, but consider your ep's. If a plain 2x is duplicating too many, then there are more options nowadays to work around this. Ultima's are actually between 2 and 2.5x . Siebert has a 1.5x. UO's 2.8x Klee is a dandy unit paricularly for a small scope with a short focal length.

Of the four mid range ones I have used over the years, all worked well. Other mid range ones that I have looked though did too. Budget priced ones less so.

The TeleVue 2x is very nice. Good optics. It is a long
Barlow; this design will mean less darkening of the field
edge for low-power eyepieces. The other ones mentioned
are also good.