View cloud cover over the UK in the latest satellite image from the Met Office

Astronomy for Beginners

Here’s where you’ll find observing guides, how-to articles and great astronomy hints and tips. Don’t forget to also check out our comprehensive astronomy dictionary.

Astronomy Dictionary
Dark frame

Exposure taken with a digital camera with the lens cap on, or aperture covered. All that is captured is noise and unwanted effects, such as hot pixels and amp glow. The dark frame is then used to remove the noise and unwanted effects when processing the image.

Dioptre adjustment

This is the ability to adjust the power of the eyepieces on a pair of binoculars to suit your eyes.