Welcome to ScopeSim! At this website you can use an interactive Telescope Simulator and Telescope Comparison to simulate a view through telescopes and eyepieces and see how they work together to produce a view through a real telescope. Click below to try out these interactive online programs.

Select a simulator: Telescope Calculator or Telescope Comparison

Telescope Calculator	Telescope Comparison

Telescope Calculator and Telescope Comparison show realistic views of what you will see with different telescopes and eyepieces. The simulated view and several readouts automatically refresh as you change the settings. This software has been used by people all over the planet to learn about telescopes, eyepieces and the inter-relationship of focal length, aperture and many other terms used to describe the capabilities of telescopes and eyepieces.

Within the program, the following telescope calculations are updated in a real time display view: telescope magnification, effective focal length, telescope focal ratio, eyepiece exit pupil size, true field of view, and eyepiece field stop. The simulated views quickly illustrates how telescopes and eyepieces work to create a telescopic view.

Telescope Calculator enables the following settings to be adjusted: telescope focal length, telescope aperture, eyepiece focal length, eyepiece apparent field of view, barlow settings, and celestial object to be viewed (Full Moon, Half Moon, Mars, Jupiter, Saturn, Pleiades).