What are the sizes of collimation screws on Current-production Celestron...

When you need to replace your collimation screws, please use the below for a refence of which screws to use: Schmidt-Cassegrain Optical Tubes:Optical SizeThread SpecificationsLengthC5M3 x 0.510mmC6...

What are the sizes of collimation screws on Current-production Celestron...

When you need to replace your collimation screws, please use the below for a refence of which screws to use: Schmidt-Cassegrain Optical Tubes:Optical SizeThread SpecificationsLengthC5M3 x 0.510mmC6...

Is there vignetting with the EdgeHD optics and reducers on a full-frame ...

A full-frame image sensor is based on the size of 35 mm film and therefore has a 42 mm diagonal. This corresponds to a 21 mm radius circle at the...

Is there vignetting with the EdgeHD optics and reducers on a full-frame ...

A full-frame image sensor is based on the size of 35 mm film and therefore has a 42 mm diagonal. This corresponds to a 21 mm radius circle at the...

Why is the Sky Tour button on my hand control not working when I want to...

The SkyProdigy manual says to use the scroll buttons to select Best of Tonight. Unfortunately the manual has an error.Here's how it works: once you press the Sky Tour button,...

Why is the Sky Tour button on my hand control not working when I want to...

The SkyProdigy manual says to use the scroll buttons to select Best of Tonight. Unfortunately the manual has an error.Here's how it works: once you press the Sky Tour button,...

Does the #93232 Deluxe Zoom Eyepiece have T-threads?

Yes. Just like the smaller regular zoom eyepiece (the #93230), the deluxe version has T-threads underneath the eyecup that can be used as a T-adapter when using the eyepiece in...

Does the #93232 Deluxe Zoom Eyepiece have T-threads?

Yes. Just like the smaller regular zoom eyepiece (the #93230), the deluxe version has T-threads underneath the eyecup that can be used as a T-adapter when using the eyepiece in...

What is precession? Do Celestron mounts correct for it?

Precession is the movement of the north celestial pole (NCP) among the constellations over long periods of time. It is caused by external gravitational forces from the Sun, Moon and...

What is precession? Do Celestron mounts correct for it?

Precession is the movement of the north celestial pole (NCP) among the constellations over long periods of time. It is caused by external gravitational forces from the Sun, Moon and...

My equatorial GoTo mount seems to need a factory reset every now and the...

Your mount may normally perform just fine, but when you conduct a two star alignment with calibration stars, the mount is way off when performing a goto to one of...

My equatorial GoTo mount seems to need a factory reset every now and the...

Your mount may normally perform just fine, but when you conduct a two star alignment with calibration stars, the mount is way off when performing a goto to one of...