What is the maximum flat image circle or radius in the regular (non-Edge...

For the C14 SCT (at f/ratio = 11.2703), the total diffraction limited depth-of-focus is 0.27944 mm. With this depth-of-focus, the image’s flatness lies within a diameter of 20.46 mm, when...

What is the maximum flat image circle or radius in the regular (non-Edge...

For the C14 SCT (at f/ratio = 11.2703), the total diffraction limited depth-of-focus is 0.27944 mm. With this depth-of-focus, the image’s flatness lies within a diameter of 20.46 mm, when...

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...

What are the optimum back focus distances for Celestron SCTs?

The back focus distances are as follows:SCTBack focus distance from primary mirror baffle tube lock ring (in)C55 inC65 inC85 inC9255.475 inC115.475 in from 3 in-2 in Reducer Plate 5.975 in...

What are the optimum back focus distances for Celestron SCTs?

The back focus distances are as follows:SCTBack focus distance from primary mirror baffle tube lock ring (in)C55 inC65 inC85 inC9255.475 inC115.475 in from 3 in-2 in Reducer Plate 5.975 in...

Does my AstroMaster 130 have a spherical or parabolic mirror? What is th...

The AstroMaster 130 has a spherical mirror. Telescope mirrors are described by their figures in terms of the curvature of the optical surface. A spherical figure is one type of...

Does my AstroMaster 130 have a spherical or parabolic mirror? What is th...

The AstroMaster 130 has a spherical mirror. Telescope mirrors are described by their figures in terms of the curvature of the optical surface. A spherical figure is one type of...

My refractor shows color fringes since it’s not an apochromatic design. ...

Many refractors are two-element conventional achromatic designs, which leave what’s called residual color. This means the designs don’t fully remove all the color left over from dispersion of light...

My refractor shows color fringes since it’s not an apochromatic design. ...

Many refractors are two-element conventional achromatic designs, which leave what’s called residual color. This means the designs don’t fully remove all the color left over from dispersion of light...