Alstar AccuFocus Electronic Telescope Focuser - Bundle with - 1.25" O-III Filter

Alstar AccuFocus Electronic Telescope Focuser - Bundle with - 1.25" O-III Filter

• Each Alstar 1.25 inch O III Filter is individually inspected and proudly inscribed with the percentage of light transmittance of the two O III emission lines
• Not only useful at light polluted sites; the contrast is also increased at dark sky sites; can be used with all 1.25 inch eyepieces; Filter made from high grade glass with dichroic interference and antireflection coatings
• Completely blocks virtually all other visible wavelengths of light so views of nebulas are optimized; Increases contrast through selective filtration Anti reflection coated to prevent glaring and ghosting
• The control box requires a standard 9V battery to operate; The 9V battery goes into the battery compartment in the rear of the control box; which can choose speeds from coarse to very fine with the adjustable speed control knob on the box
• Accufocus electronic focuser cannot be used on Maka; DOB type telescopes and telescopes with APO two speed focusing; but only on telescopes with single speed focusing such as some brands of refractors and reflectors in the 60 to 127 mm range