{"id":38695,"date":"2022-11-14T10:01:38","date_gmt":"2022-11-14T10:01:38","guid":{"rendered":"https:\/\/www.skyatnightmagazine.com\/?p=113618"},"modified":"2022-11-14T10:19:11","modified_gmt":"2022-11-14T10:19:11","slug":"how-to-create-a-24-hour-star-trails-image","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/how-to-create-a-24-hour-star-trails-image\/","title":{"rendered":"How to create a 24-hour star trails image"},"content":{"rendered":"

<\/p>

By Mary McIntyre\n \t\t<\/p>

Published: Monday, 14 November 2022 at 12:00 am<\/p>

\n\n

Star trails are relatively simple to do yet produce very striking results, especially when centred around the north or south celestial poles.<\/p>\n

These images capture the movement of Earth as it rotates on its axis, producing star trails that are comprised of fragments of concentric rings.<\/p>\n

If you are in the polar regions during the winter and have clear, dark skies for 24 hours, the trails will form complete circles, including the pole star Polaris \u2013 also known as the North Star<\/a> \u2013 because it is not perfectly aligned with the celestial pole.<\/p>\n

However, you don\u2019t need 24 hours of darkness to create a 24-hour star trails image.<\/p>\n

The above image was captured from the UK, and is effectively a 24-hour star trails image.<\/p>\n

In this guide, we\u2019ll show you exactly how we did it.<\/p>\n

For more advice, read our guide on how to use a DSLR camera<\/a> or our beginner\u2019s guide to astrophotography<\/a>.<\/strong><\/em><\/p>\n

\"""\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Star trails captured by Adam Jeffers, Cookstown, Northern Ireland, August 2020 Equipment: Nikon D800E DSLR, Nikon 28\u201380mm lens, static tripod<\/span><\/figcaption><\/div>\n

What is a 24-hour star trails image?<\/strong><\/h2>\n

Most of us will never experience a polar winter, but it is still possible to create a 24-hour star trail photograph<\/a> by merging together a stack of many images taken with the same setup, from exactly the same spot, on different nights throughout the year.<\/p>\n

Although taking a star trail image on a single night is straightforward, replicating it exactly on multiple dates, then merging them together successfully, is the challenge here.<\/p>\n

First, the camera location must be identical.<\/p>\n

We placed marks on the ground to ensure the tripod was in exactly the same spot, but attaching the camera to a fixed structure would be even better.<\/p>\n

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Point at the north celestial pole to give your stra trails that attractive circular focal point. Credit: Anthony Beavers.<\/span><\/figcaption><\/div>\n

Focus must also be the same, otherwise the width of the star trails will differ, and they won\u2019t line up perfectly.<\/p>\n

Circumpolar star trails can be created under moonlight, but doing so will affect the fainter stars, so try to ensure the Moon\u2019s brightness \u2013 its phase \u2013 is consistent between sessions.<\/p>\n

Also, when you blend your final stacked<\/a> images, the overlapping regions will be brighter, so only stack what\u2019s necessary to complete the full circle.<\/p>\n

Pick your foreground wisely<\/span><\/strong><\/h2>\n
\"""\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
A good foreground can really make a star trails image! Credit: James Billings<\/span><\/figcaption><\/div>\n

Another consideration is the foreground. It\u2019s important to have something in the foreground for context and scale.<\/p>\n

I had a large tree in mine, which grew during the year and then required an extra layer-masking step at the end to compensate for the different tree size.<\/p>\n

You might want to opt for a non-organic foreground object!<\/p>\n

\"""\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Star Trails over 18th Century Loop Tower by Peter Brown, Guernsey, Channel Islands. Equipment: Cannon 1100D Camera on Tripod.<\/span><\/figcaption><\/div>\n

Choose some potential imaging dates that are spread across the whole year and if you have a clear sky forecast, be ready on those nights (for help, read our guide to weather forecasting for astronomy<\/a>).<\/p>\n

I took images on seven nights during the year, but only used the photos taken in February, April, July and November.<\/p>\n

During the winter months you will have many more hours of imaging available to you, but in the summer you need to grab every minute of darkness.<\/p>\n

If thin cloud moves through your field of view, don\u2019t worry; the stars will still shine through.<\/p>\n

\"""\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Star trails captured on a smartphone with NightCap by Iain Todd, Bristol, UK, 26 February 2022.<\/span><\/figcaption><\/div>\n

Issues such as aircraft lights can be omitted from the image stack by using a program called StarStaX, which can fill the gaps.<\/p>\n

Before you attempt to merge the stacked images, adjust the brightness and colour balance to make them as similar to each other as possible.<\/p>\n

You may also have to apply a lens distortion correction to successfully line up the images. But all this effort is well worth it for the end result.<\/p>\n

What you\u2019ll need<\/strong><\/h2>\n
  • A DSLR camera with a widefield lens and a high-power battery or mains power lead<\/li>\n
  • A remote shutter release cable that locks in place<\/li>\n
  • A sturdy tripod<\/li>\n
  • A dew heater to prevent the lens from fogging up during long imaging sessions<\/li>\n
  • Software for image stacking and processing, eg StarStaX for stacking,<\/span> and Photoshop or GIMP for merging and processing the stacked images<\/li>\n<\/ul>

    Create a 24-hour star trails image, step-by-step<\/strong><\/h2><\/body><\/html>\n
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    By Mary McIntyre Published: Monday, 14 November 2022 at 12:00 am Star trails are relatively simple to do yet produce very striking results, especially when centred around the north or south celestial poles. These images capture the movement of Earth as it rotates on its axis, producing star trails that are comprised of fragments of […]<\/p>\n","protected":false},"author":24,"featured_media":38696,"template":"","categories":[34],"acf":{"readingTimeMinutes":"4"},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/how-to-create-a-24-hour-star-trails-image.jpg",1200,933,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/how-to-create-a-24-hour-star-trails-image-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/how-to-create-a-24-hour-star-trails-image-300x233.jpg",300,233,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/how-to-create-a-24-hour-star-trails-image-768x597.jpg",768,597,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/how-to-create-a-24-hour-star-trails-image-1024x796.jpg",800,622,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/how-to-create-a-24-hour-star-trails-image.jpg",1200,933,false],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/11\/how-to-create-a-24-hour-star-trails-image.jpg",1200,933,false]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"By Mary McIntyre Published: Monday, 14 November 2022 at 12:00 am Star trails are relatively simple to do yet produce very striking results, especially when centred around the north or south celestial poles. These images capture the movement of Earth as it rotates on its axis, producing star trails that are comprised of fragments of…","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed\/38695"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/rss_feed"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/38696"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=38695"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=38695"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}