Tools

Here you'll find quick references, calculators, charts, and infographics to help with your questions and schooling on astronomy and other tech interest related to outdoor discovery.

Weather and cloud outlook near you

Cloud Forecast – From Clear Outside will give you the outlook for your local atmospheric conditions.

Calculators for Telescopes

Use the Telescope Nights calculators for quickly working out metrics for telescopes:

Focal ratio (f/)

How to calculate telescope magnification

How to calculate the magnifying power of a telescope? Telescope magnification is calculated by dividing the focal length of the telescope by the focal length of the eyepiece and multiplying the result by the magnitude of the Barlow lens (if using). Or, you can simply use the following tool to calculate telescope magnification. It’ll guide you on the usefulness of the magnification also.

True field of view

The true field of view (measured in degrees) is how much of the sky you are likely to see through your eyepiece when using your telescope.

How to calculate the true field of view of your telescope? It is the apparent field of view divided by the magnification. You typically find the apparent field-of-view (AFOV) value listed in the product description for the eyepiece and magnification is simply the telescope focal length divided by the eyepiece focal length.

COMING SOON!…

Telescope focal Length

Calculators for Binoculars

For binocular users…COMING SOON!…

Binocular Field of View in meters

Binocular field of view in Degrees

Charts / Quick References

Dobsonian collimation

Useful when collimating Dobsonian telescopes…For more details see our article on collimating a Dobsonian.

telescope-star-test

Star testing magnifications

magnification-for-star-testing

Planet viewing

Rough idea of magnification to use when wanting to observe planets or the moon. See also our article on the best telescopes for planet viewing.

magnifications-to-see-planets

Infographics

The following is for education purposes. We are happy for you to use these graphics on your page or social media account, but ask that you acknowledge us by adding a link to our site: telescopenights.com – thank you.

Moon

Moon phases…

phases of the moon infographic
Phases of the moon infographic

Jupiter

Features, metrics, and moons of Jupiter

Jupiter Galilean moons infographic
Jupiter infographic and measurements of moons

Saturn

Features, metrics, and moons of Saturn

Saturn infographic showing its moons
Saturn infographic showing its moons

Stars

Our Sun and stars like our Sun…See also our article on the type of stars in space.

Sun infographic showing sun spots and zones
Sun infographic showing zones and other features