{"id":21536,"date":"2021-08-05T07:56:31","date_gmt":"2021-08-05T07:56:31","guid":{"rendered":"https:\/\/www.skyatnightmagazine.com\/?p=95815"},"modified":"2021-08-05T08:09:10","modified_gmt":"2021-08-05T08:09:10","slug":"what-is-a-harvest-moon","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/what-is-a-harvest-moon\/","title":{"rendered":"What is a Harvest Moon?"},"content":{"rendered":"

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By Pete Lawrence\n \t\t<\/p>

Published: Thursday, 05 August 2021 at 12:00 am<\/p>

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Harvest Moon is the name given to the full Moon that happens closest in date to the first day of autumn, known as the autumn equinox in the northern hemisphere. This is when day and night are the same length.<\/p>\n

In 2021, the full Moon on 20 September will be the closest full Moon to the Northern Hemisphere\u2019s autumn equinox. Consequently, this will be the Harvest Moon for 2021.<\/p>\n

\""An\"<\/div>
A glowing orange full Harvest Moon rising. Credit: Ray Wise \/ Getty Images<\/span><\/figcaption><\/div>\n

Some believe the Harvest Moon is much bigger or brighter than other full Moons in the year. This isn\u2019t true though.<\/p>\n

This belief may have come about due to a complex optical illusion that makes the Moon look bigger when it\u2019s lower down near the horizon.<\/p>\n

\""A\"<\/div>
Credit: Jim Kruger \/ Getty Images<\/span><\/figcaption><\/div>\n

How to observe a Harvest Moon<\/strong><\/h1>\n

Around the time of year that the Harvest Moon appears, the Sun goes down almost due west, so the full Moon will be rising near to due east.<\/p>\n

As the Moon rises, see if it has a wonderful ochre red colour, especially when it\u2019s low on the horizon.<\/p>\n

This is an effect of the Moon\u2019s light being filtered, as it travels through more of the Earth\u2019s atmosphere than when it\u2019s overhead.<\/p>\n

Since red light is scattered least by the Earth\u2019s atmosphere, the Moon takes on this lovely red colour.<\/p>\n

The lower and less built-up your horizon, the better your chance of seeing the Harvest Moon rising in all of its glory \u2013 a fantastic sight that heralds the start of autumn.<\/p>\n

\""Harvest\"<\/div>
Harvest Moon Rising over Mount Teide, Tenerife by Peter Louer, Tenerife. Equipment: Canon 700D, Canon 100-400mm lens.<\/span><\/figcaption><\/div>\n

How to photograph a Harvest Moon<\/strong><\/h1>\n

The sight of a big, bright, almost-full Moon is still pretty impressive. When it\u2019s low in the sky, the \u2019Moon Illusion\u2019 makes our nearest neighbour look much larger than normal and this is where nature plays a cruel trick on photographers.<\/p>\n

With the full Moon having just risen and looking enormous, an average camera shot of it will show that it\u2019s actually pretty tiny.<\/p>\n

To see any detail on it, you\u2019ll need at least a 200mm or longer focal length lens or telescope.<\/p>\n

A Harvest Moon presents the perfect opportunity to catch that detail. The easiest way to do this is to use a long focal length lens or telescope with a DSLR fitted.<\/span><\/p>\n

Alternatively, if you have a steady hand, afocal photography (the technique where you point a camera or smartphone down the eyepiece<\/a>) can work surprisingly well.<\/span><\/p>\n

For more info on lunar astrophotography, read our guide on how to photograph the Moon<\/a> or how to use a DSLR camera<\/a>.<\/strong><\/em><\/p>\n

\""Photographing\"<\/div>
Credit: m-gucci \/ Getty Images<\/span><\/figcaption><\/div>\n

If your lens or telescope\u2019s focal length is long enough, say above 700mm, then you can capture plenty of detail on the lunar surface.<\/p>\n

But close examination of your shots will reveal two issues: the image is virtually monochrome and its detail is a little blurry.<\/p>\n

You may think the Moon is fairly colourless and grey, but you\u2019d be wrong. There\u2019s actually quite a lot of subtle colour on offer.<\/p>\n

One way to reveal it is to super-saturate your shot, but this needs to be done with care because it can bring out noise and produce artefacts (features that aren\u2019t actually there).<\/p>\n

\""Crich\"<\/div>
Crich Harvest Moon by Matt Jarvis, Crich, Derbyshire, UK. Equipment: Canon PowerShot SXHS60 bridge camera.<\/span><\/figcaption><\/div>\n

When you\u2019ve finished the saturation process (outlined in the step-by-step guide below), the result will typically be pretty gaudy.<\/p>\n

There\u2019s a trick to improve things: you can use the saturated colour image to provide just the colour information and a sharper, luminance image for the tone and detail.<\/p>\n

If you\u2019re using just a DSLR shot, the luminance component can be provided from your original image of the Moon.<\/p>\n

Simply convert it to a greyscale image or, if available, use a function in your graphics editor to turn it to a black and white image.<\/p>\n

Load the saturated colour image into a layer-based graphics editor and make a safety duplicate of the layer. To remove excessive noise, simply apply a reasonably strong Gaussian blur.<\/p>\n

\""Harvest\"<\/div>
Harvest Moon by Sarah and Simon Fisher, Bromsgrove, Worcestershire, UK. Equipment: Canon 600D, Maksutov 127mm telescope<\/span><\/figcaption><\/div>\n

Your aim is to produce an image showing relatively smooth areas of colour, free from random splodges of unnatural colour. Don\u2019t worry about losing detail \u2013 that\u2019s what the luminance image is for.<\/p>\n

It may take a few attempts to get the right amount of blurring, but this is why you\u2019re working on a duplicate layer. If things go wrong, just delete and start again on another duplicate of the original colour saturated version.<\/p>\n

To restore the missing detail from the image, load the greyscale luminance image as a new layer above the saturated and blurred colour image.<\/p>\n

Set the greyscale image\u2019s blend mode to luminance and you\u2019ll then have a beautifully detailed image of the Moon showing enhanced colour.<\/p>\n

If you have access to a monochrome high-frame-rate camera, use this to produce a sharper, highly detailed luminance image via stacking software such as AutoStakkert! or RegiStax<\/a>.<\/p>\n

For more on this, read our guide on how to stack DSLR images of the Moon<\/a>.<\/p>\n

Recommended equipment<\/strong><\/h1>\n