-
Step 1
Find out the value of the apparent field of view. Every eyepiece has its own value of the apparent field of view. This value of your eyepiece is supplied from the manufacturer.
-
Step 2
Find the value of magnification. The value for magnification can be found out by dividing the value of the focal length of your telescope by the focal length of the eyepiece. Assuming your telescope has a focal length of 750 mm and the focal length of your eyepiece is 10 mm, the magnification for your telescope is equal to 750 / 10 = 75. It is usually denoted as 75X. The focal length for this model is 900 mm.
-
Step 3
Divide the value of the apparent field of view by the value of magnification to get the value of the field of view. For example, your eyepiece has apparent value of field of view at 50 degrees and magnification of 75X, then the value of the actual field of view is equal to 50 degrees / 75X = 0.66 degrees.
- How to Focus the Sky-Watcher SK909AZ3 Refractor Telescope
- How to Align the Finderscope of the Sky-Watcher SK909AZ3 Refractor Telescope
- How to Attach the Skywatcher SK909AZ3 Refractor Telescope on the Mount
- How to Use a Camera Adapter Tube With the Sky-Watcher SK909AZ3 Refractor Telescope
- How to Use the Barlow Lens With the Sky-Watcher SK909AZ3 Refractor Telescope










