Popular Articles

How to Determine Which Eyepieces to Use with Your Telescope
SCT & EdgeHD Collimation Guide
Aligning Your Celestron Finderscope: A Step-by-Step Guide
Why is my Telescope Showing Everything Upside Down? Is There Something Wrong with it?
Which scope aperture is best for different kinds of objects?

What does ED stand for on my Sport Optics' scopes?

 ED means "extra-low dispersion" and refers to the composition and optical properties of the glass used for the lenses. ED glass is specially formulated, including rare-earth compounds to...

What does ED stand for on my Sport Optics' scopes?

 ED means "extra-low dispersion" and refers to the composition and optical properties of the glass used for the lenses. ED glass is specially formulated, including rare-earth compounds to greatly r...

How do I use my spotting scope for photography/digiscoping?

Your spotting scope doubles as a telephoto lens and can be used in several ways to take photographs of terrestrial and even celestial objects.Celestron’s Ultima spotting scopes have a T-adapter...

How do I use my spotting scope for photography/digiscoping?

Your spotting scope doubles as a telephoto lens and can be used in several ways to take photographs of terrestrial and even celestial objects.Celestron’s Ultima spotting scopes have a T-adapter...

What are eyecups?

Eyecups are simply shades that prevent extraneous light from distracting your vision or entering the eyepiece while using your binoculars. Most consumer binoculars have soft rubber eyecups that ca...

What are eyecups?

Eyecups are simply shades that prevent extraneous light from distracting your vision or entering the eyepiece while using your binoculars. Most consumer binoculars have soft rubber eyecups that ca...

What is interpupillary distance? How do I adjust it on my binoculars?

Interpupillary distance (IPD) is the distance between the pupils of your eyes measured from center to center when your eyes are focused on infinity. IPD varies from person to person,...

What is interpupillary distance? How do I adjust it on my binoculars?

Interpupillary distance (IPD) is the distance between the pupils of your eyes measured from center to center when your eyes are focused on infinity. IPD varies from person to person,...

Understanding the Magnification and Objective Lens of my Binocular and Spotting Scope

Understanding the Magnification and Objective Lens of my Binocular and S...

Binocular size is defined by its magnification and objective, but if you are new to the hobby, what do these mean when observing. Below we have how to identify these...

Understanding the Magnification and Objective Lens of my Binocular and S...

Binocular size is defined by its magnification and objective, but if you are new to the hobby, what do these mean when observing. Below we have how to identify these...

My Celestron mount slews in the wrong direction. Is this an encoder prob...

It could be an encoder problem. The encoder is a light-emitting diode (LED) device that measures how much the motor has turned. Try this general test of the encoders:For Alt-Azimuth...

My Celestron mount slews in the wrong direction. Is this an encoder prob...

It could be an encoder problem. The encoder is a light-emitting diode (LED) device that measures how much the motor has turned. Try this general test of the encoders:For Alt-Azimuth...