BBC Sky at Night Magazine

Colourful captures

With the right setup you can show Orion is more than just white stars against a black background

-

EXPERIENCE LEVEL Beginner WHAT YOU’LL NEED A basic DSLR or bridge camera fitted with a lens that allows manual focusing (some compact digital cameras will also work depending on the lens/focusing mechanism they use). You’ll also need a photograph­ic tripod and your camera will need to be able to take exposures of a few seconds.

The colour variation of Orion’s bright stars is one of the most captivatin­g things about the constellat­ion, yet it can be tricky to capture these wonderful hues as the chromatic aberration in some camera lenses overwhelms the true star colour. One method for showing the tints of stars such as Betelgeuse, Rigel and W Orionis is to manually defocus the image. It’s a technique that was made famous by the renowned astrophoto­grapher David Malin many years ago. You can use this method with a wide lens (or a fast long lens) on a static tripod, as long as you use short exposures – a second or so in the case of a longer lens. All you do is frame the star (or constellat­ion), defocus the lens a little by hand and capture an exposure, usually at a mid-to-high level ISO setting. In the two composite images below we focused on Betelgeuse and Rigel. We captured a number of exposures and in between each one we defocused the lens a bit more. Then we combined them into one frame using processing software. It’s a very artificial compositio­n, but it does give a flavour of one of the things that makes observing and imaging Orion special.

 ??  ?? Combining progressiv­ely defocused images of Betelgeuse (left) and Rigel (right) will highlight the contrastin­g colours of Orion’s brightest stars
Combining progressiv­ely defocused images of Betelgeuse (left) and Rigel (right) will highlight the contrastin­g colours of Orion’s brightest stars
 ??  ??

Newspapers in English

Newspapers from United Kingdom