High-Power Barlows work by reducing the convergence of the light cone heading into
the eyepiece. The Barlow effectively increases the focal length of the telescope, thereby
increasing the magnifying power of any eyepiece used with the telescope and Barlow:
telescope focal length
X Barlow magnification = total magnification
eyepiece focal length
Features of High-Power Barlow lenses
High-Power 1.25" Barlows fit standard 1.25" accessory holders and are used with 1.25"
eyepieces. The High-Power 2" Barlow fits 2" focusers and accommodates 2" eyepieces.
The 2" Barlow includes a separate 2"-to-1.25" adapter that allows use of 1.25" eyepieces
and accessories
(Figure 2)
. When it’s removed the 2" collar is available for use with 2"
eyepieces or accessories.
Each High-Power Barlow lens has an enhanced 4-element lens design that minimizes
chromatic and spherical aberrations and preserves sharpness and contrast. Images
appear flatter, sharper, and better color-corrected than with standard achromatic
Barlows. And with a High-Power Barlow you get the full benefit of the longer eye relief
typical of longer-focal-length eyepieces, versus using a shorter focal length eyepiece to
achieve the same magnification.
Figure 2.
The 2
"
model includes a 2
"
-to-1.25
"
adapter to accept 1.25
"
eyepieces.
