2x BIG Barlow 2" Telescope and Observatory: DurangoSkies.com

2x BIG Barlow 2"	$205.00
[BWC-2200]

Offered in a 2x magnification, the Big Barlow is ideal for Newtonian scope owners. It will be parfocal with both 2" and 1¼" eyepieces in this application. Features include threads for 48mm filters, captive lock screw and full multi-coatings.

Barlow Interface
You can double the power of any eyepiece with the 2x Big Barlow, but adding the interface lens brings the pupil back to original position when used with long focal length eyepieces such as the Panoptic 41, 35, or 27mm 2" models. The combination of interface and Big Barlow mimics the Powermate concept.

Note: The Big Barlow is not recommended for use with 2" diagonals because it's length prevents it from being parfocal. With some telescopes, focus might not be reached, particularly when the interface lens is also used with it. A far better approach with no potential problems in any scope or with any eyepieces is to use the 2" 2x Powermate (#PMT-2200), which essentially includes the interface function.

“Tele Vue's Big Barlow doubled the power but, like an optically perfect window, never gave any other indication that it was in the light path. The airy disc and surrounding diffraction rings were perfect, with no sign of astigmatism or coma. It will provide outstanding optical performance with all your eyepieces.”
— Alan Dyer
Astronomy Magazine