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EXPERIENCE LEVEL Intermediate WHAT YOU’LL NEED A DSLR, a tracking mount and either a relatively long focal length camera lens (between 100 and 300mm focal length on a full-format DSLR) or a short focal length refractor. You could use a CCD camera, but the field of view produced by your setup will need to be at least 5° across or you’ll need to mosaic.
One of the things that makes Orion so attractive for astrophotography is the diversity of deep-sky objects within its borders, from pinkish-red star forming regions to blue-tinted reflection nebulae.
The proximity of these targets to one another means that long-exposure widefield imaging of Orion can produce some spectacular compositions. Not only do such wide-field images show the positions of objects such as the Orion and Horsehead Nebulae in relation to one another, but they can also reveal the rarely seen fainter surroundings of objects that are usually given the ‘close-up’ treatment, such as the aforementioned nebulae.
A DSLR with a long focal length lens and mounted on some form of equatorial tracking mount is probably the simplest setup with which to get started in wide-field imaging. Unlike most deep-sky imaging, wide-field deep-sky astrophotography generally doesn’t require autoguiding, as it’s possible to capture good data with unguided sub-exposures of just a minute or two.
With fast prime lenses and those relatively short exposure lengths, you may be surprised at how easily you can pick up some of Orion’s most recognisable deepsky objects. For the best results capture multiple sub-exposures (as well as dark frames and flat fields) and then calibrate and stack them, using software such as the free DeepSkyStacker, before final enhancements in your preferred imageprocessing software.