What is this Simulator showing me?

Ever wondered why some telescope views look like you are looking through a narrow soda straw, while others feel like a "spacewalk"? The secret lies in the Field of View (FOV).

This simulator calculates your True Field of View (TFOV) based on your equipment. It visually demonstrates how much of the sky you can actually see at once.

The Two Types of FOV (Confusing? Read This)

There are two numbers you need to know, and they are often confused:

1. Apparent Field of View (AFOV): This is the number written on your eyepiece (e.g., 52° or 66°). It tells you how "wide" the window feels. A higher number means a more immersive experience.
2. True Field of View (TFOV): This is the actual slice of the sky you see. It depends on your magnification.

The Formula: True FOV = Apparent FOV / Magnification

Example: A 52° eyepiece at 50x magnification gives you a tiny 1.04° slice of the sky.

Why You Need "Goldline" Eyepieces (The Upgrade)

Most telescopes come with cheap "Plossl" or "Huygens" eyepieces. These usually have a narrow AFOV of about 40-50 degrees.

Try this in the simulator above:

1. Select "The Moon".
2. Change "Apparent FOV" from 52 to 66.
3. Watch how the circle expands! You see more space around the moon.

This is why we recommend upgrading to "Goldline" (66°) or "Ultrawide" (82°) eyepieces. They make finding objects much easier because you can see more area at once.

👉 Best Budget Upgrade: SvBony 66-Degree "Goldline" Series

Frequently Asked Questions

Why can't I see the whole Moon?

If the Moon is cut off in the simulator (or your telescope), your magnification is too high. Try using an eyepiece with a larger number (e.g., switch from 10mm to 25mm) to zoom out.

What FOV do I need for Andromeda Galaxy?

The Andromeda Galaxy is huge—about 6 times wider than the Full Moon! To see the whole galaxy, you need a TFOV of at least 3 degrees. Use the simulator to check if your telescope can reach that wide.