How to photograph the Moon

Everything you need to know to take photos of the Moon, including equipment, techniques, tips and tricks and how to photograph the Moon with a smartphone.

how to photograph the Moon. Credit: Pete Lawrence

With its shifting phase and the wobbles of libration bringing myriad new features into view each night, the Moon is a wonderful target for photographers of all abilities. As the largest object in the night sky seen from Earth, it’s an obvious place to start when you’re learning to take photos of the night sky.

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But for all its size, proximity and brightness, it takes great attention to detail to capture top-quality images of the Moon.

Here we’ll show you how to do it, starting with the astrophotography equipment you need and then the techniques that will help you to capture better lunar shots, whether you’re using a DSLR or a smartphone.

If you’re stuck for ideas, we’ll also look at 6 classic sights on the Moon that everyone should have a go at photographing.

And if you’re already a seasons lunar astrophotographer, have a go at capturing images of the Moon for science.

The Moon - 09th May 2017, by Chris Campbell.
The Moon captured on 9 May 2017, by Chris Campbell from Cheshire, UK using a Microsoft HD3000 Webcam and Sky-Watcher 130/900 telescope.

Equipment for photographing the Moon

Anyone with a telescope and either a smartphone or a compact camera can take a decent image of the Moon. Just hold your camera up to the telescope’s eyepiece and start snapping away.

This technique is known as ‘afocal photography’ and if you already have a camera and telescope, you don’t need anything else to get started.

A DSLR provides you with several options. They can be used to take afocal shots, just like smartphone and point-and-shoot cameras. Or they can be turned directly to the night sky to capture nightscapes.

Equipment for photographing the Moon: a telescope and mount, a compact camera, a high frame rate camera, a laptop and a digiscoping bracket for afocal photography
Equipment for photographing the Moon: a telescope and mount, a compact camera, a high frame rate camera, a laptop and a digiscoping bracket for afocal photography

Bear in mind that the Moon will appear small in such an image taken with an APS-C camera’s standard 18-55mm lens. To increase the size of the Moon’s disc in your images and reveal more detail on its surface, you’ll need a longer focal length lens.

A lens with a focal length of 300mm or more will show the lunar maria as well as some of the more prominent craters and mountains. For more on this, read our guide to photographing craters on the Moon.

That DSLRs have detachable lenses means that they can be connected directly to a telescope, essentially turning the telescope into the camera lens.

You’ll need a T-adaptor and a T-ring. The T-ring is brand-specific. It mounts on your DSLR and screws into the T-adapter, which then attaches to your telescope.

Although the newest models of DSLRs can shoot video, they’re not ideal for high-resolution lunar imaging, and this is where high frame rate planetary cameras come in.

Celestron Advanced VX 700 Maksutov-Cassegrain telescope review
The Celestron Advanced VX 700 Maksutov-Cassegrain telescope. Telescopes like these are popular with advanced lunar astrophotographers.

These cameras are capable of taking short videos and shoot many frames per second. You can use any telescope you like, although large aperture Schmidt-Cassegrains and Maksutov-Cassegrains are popular choices with top lunar photographers.

This is because their longer focal lengths are well suited to close-up imaging of the Moon, and compared to a high-quality refractor telescope you get a much larger aperture for your money.

Whatever type of telescope you use, make sure it’s well collimated, by ensuring that its optics are carefully aligned to produce the sharpest image possible. Your telescope’s instruction manual will show you how to do this.

Or, read our guides on how to collimate a Schmidt-Cassegrain and how to collimate a Newtonian.

Bresser EXOS 2 Go-To mount header
The Bresser EXOS 2 Go-To mount. A mount like this will help you keep the Moon in your field of view.

As in any area of astronomy, your telescope’s mount needs to be rock solid and stable. The ability to track the Moon – either with a motor drive or with full Go-To capability – is a must if you’re using a high frame rate camera.

A mount’s drives should be set to track at the lunar rate, not at the rate the stars move across the sky.

If you’re using a Go-To mount, take time to set it up properly, otherwise you may find yourself having to make continuous, tiresome tracking adjustments when imaging.

If you’re using a high frame rate camera you’ll need a computer to run it. This computer will also need capture software installed if your camera doesn’t have any of its own.

Essential lunar astrophotography accessories

Red filter

red filter for telescope

If you’re using a monochromatic planetary camera you might find it helpful to fit a red filter when capturing lunar images. Using one can help produce a crisper final picture. For more info read our guide to telescope filters.

Barlow lens

Meade 126 Barlow lens

A Barlow lens is must for detailed close-ups of the lunar surface and its craters, whatever camera you use. It increases the focal length and the magnification of your system, typically by two or three times.

Smartphone bracket

NexYZ 3 Axis Universal Smartphone Adapter

Holding a smartphone squarely over an eyepiece while you take a photo is a delicate art. You can make things easier with a dedicated bracket to do the job for you. Follow our guide to build your own smartphone holder.

Techniques for photographing the Moon

The first step when setting out to image features on the Moon is to decide what your target is and work out the best time to capture it. There are various apps and programs that can help you to do this – a few of our favourites are listed below.

To reveal intricate surface textures and the rugged nature of the lunar crust, it’s best to take your shots when your target is lit from an angle.

This will be when it’s located near the line between the light and dark sides of the Moon – known as the terminator.

This is particularly important when capturing very small craterlets and other subtle lunar features such as rilles. When they’re illuminated from above, they can be practically invisible.

Mare Crisium on the Terminator by Ian Peck, Londonderry, Northern Ireland.
Mare Crisium on the Terminator, photographed by Ian Peck, Londonderry, Northern Ireland.

Atmospheric turbulence can also blur and distort your view of the Moon, in a similar way to how heat haze rising from a road on a hot day can distort your vision. The extent to which the view is undulating is known as the seeing.

If the view is mostly steady, without much turbulence, the seeing is said to be good. Good seeing is what you need to capture the sharpest lunar images.

You can’t control the seeing conditions, but there are other things you can do to improve the view.

One is to leave your telescope outside to cool down to the ambient temperature before you start imaging. This will reduce the amount of wobbling in your image caused by heat rising in and around your telescope.

Never take images from indoors looking out, either through a window, skylight or near a doorway. Heat escaping from the house will cause the view to shimmer wildly, making high-resolution imaging very difficult.

Start photographing the Moon

Laptop and telescope set up, you're ready to start photographing the Moon. Credit: Will Gater
Laptop and telescope set up, you’re ready to start photographing the Moon. Credit: Will Gater

Once you’ve set your telescope up and left it to cool down for about an hour or so, you can connect your computer equipment and start imaging.

If you need to make minor corrections to the tracking on your Go-To or driven mount while imaging, be sure you know which button to press on the hand controller to move the image on screen in the direction you actually want.

You can check this by rotating the camera in the eyepiece holder so that when you press the left or up button, for example, the image does indeed move left or up.

If you’re using a camera with a monochrome chip and the seeing conditions aren’t perfect, it’s a good idea to use a red filter on the camera.

Red wavelengths of light are less affected by poor seeing, so using a red filter should improve the view.

The Moon with a filter (left), and without a filter (right). Credit: BBC Sky at Night Magazine.
The Moon with a filter (left), and without a filter (right). Credit: BBC Sky at Night Magazine.

This is also the time to make sure your capture software is set up correctly and is recording to a hard drive with sufficient free space.

Record each night’s captures to a fresh folder so they can be easily located later on. Most capture software will have a live window that shows you the view the camera is seeing. This is crucial when it comes to focusing.

To focus the camera, make sure it’s securely locked in the eyepiece holder – you don’t want it to move out of focus as you’re imaging.

Then, pointing the telescope at the Moon’s terminator, adjust the focus knob. The high contrast between light and dark at the terminator makes it easy to judge when the image is at its sharpest.

You can then move the telescope to your target, knowing it’s in focus. Once you’re ready to image, take a short video of just over a minute. At 15fps (frames per second) this should give you more than 900 frames to sift through.

Why video is best for imaging the Moon

Left: a single frame from an AVI of the Moon’s Vallis Alpes. Right: the final stacked image, made up of 720 frames.
Left: a single frame from an AVI of the Moon’s Vallis Alpes. Right: the final stacked image, made up of 720 frames.

To end up with a high-resolution close-up of the lunar surface it is better to record a video than take stills. Why is this?

The answer doesn’t lie out in space but closer to home, in Earth’s atmosphere. When looking at the Moon at high magnification on an average night, you’ll notice the view undulating, with moments of steady, sharp views and then brief blurred instants.

Since they generally only take single still images, the shots from a DSLR or point-and-shoot camera risk being blurred by this atmospheric turbulence at the moment when the shutter fires.

The steadiness of the atmosphere can mean the difference between a blurred picture (left) and a clear one (right). Credit: Pete Lawrence
The steadiness of the atmosphere can mean the difference between a blurred picture (left) and a clear one (right). Credit: Pete Lawrence

A short video taken with a webcam or planetary camera, recorded in the AVI format, has many frames each second. It enables the sharpest moments of clarity to be selected.

You can then stack these frames together using specialised software and process them further to bring out tremendous detail on the Moon’s surface.

So for wide-field shots of the Moon, DSLRs are fine. But when it comes to high-resolution close-ups of its mountains and craters, it’s the dedicated planetary cameras that come up trumps.

Best free apps and software for photographing the Moon

Moon Globe

Moon globe app

This great free app can be used on your iPhone, iPod Touch or iPad and is also available on Android. It shows what the Moon looks like for a given date and time, complete with shadow details.

Where to get it Your app store

Stellarium

STELLARIUM

This free planetarium software is handy for working out where the Moon will be. It’s great for when you’re planning a long night of imaging to create a lunar mosaic. For more help, read our guide on how to install and use Stellarium.

Where to get it stellarium.org

Virtual Moon Atlas

VIRTUAL MOON ATLAS

An authoritative piece of freeware for planning your observations in detail using an interactive atlas and feature-rich information panel.

Where to get it ap-i.net/avl/en/start

6 targets to photograph on the Moon

For more sights to observe and photograph on the lunar surface, read our guide to the Moon’s best features.

1

Crater Clavius

Clavius is a wonderfully rugged moon crater, ripe for observing with a telescope. Credit: Pete Lawrence
Credit: Pete Lawrence

This is a great target if you’re trying to push your equipment to its limit. See how many of the small craterlets on the crater floor you can capture. For more info, read our guide on how to see crater Clavius.

2

Crater Copernicus

Copernicus crater on the Moon, by John Brady.
Credit: John Brady.

Being one of the most stunning craters on the Moon, Copernicus is a wonderful imaging target. See if you can capture its magnificent terraced walls.

3

Montes Apenninus

Montes Apenninus, by Andrew Houghton.
Credit: Andrew Houghton.

This chain of peaks is one of the great lunar mountain ranges and a good target for afocal photography. It stretches 600km across the Moon’s surface.

4

Rupes Recta

Rupes Recta, by Michael Lloyd
Credit: Michael Lloyd

Also known as the ‘Straight Wall’, Rupes Recta is an enormous fault on the lunar surface. The trick is to catch it under the right illumination to see it clearly.

5

Vallis Alpes

Vallis Alpes. Credit: Oliver Schneider / CCDGuide.com
Credit: Oliver Schneider / CCDGuide.com

This valley cuts straight through the lunar Alps. The challenge here is to see if you can capture the elusive rille that runs all the way along its length.

6

Crater Tycho

Tycho crater on the Moon, by FERNANDO OLIVEIRA DE MENEZES
Credit: Fernando Oliveira De Menezes, using a ZWO ASI290MC camera and a C11 Edge HD telescope.

Crater Tycho is surrounded by ejecta rays – brighter material that was flung out by the impact that formed the crater. It has a huge peak at its centre.

Photograph the Moon with a smartphone

Photographing the Moon through a telescope with a smartphone. Credit: m-gucci / Getty Images
Credit: m-gucci / Getty Images

Here we’ll show you how to use a smartphone to take images of the Moon with afocal imaging, the technical term for simply aiming your smartphone’s camera down your telescope’s eyepiece.

There are two ways to do this: one is to simply hold your phone’s camera over the eyepiece, the other is to use a smartphone adaptor, which attaches to your telescope’s eyepiece to provide greater stability.

You wouldn’t think it would be difficult to point a smartphone camera down the eyepiece of a telescope, but there are techniques that need to be mastered.

For more info, read our guide to smartphone astrophotography or the best gadgets to turn your smart phone into an astrophotography camera.

Altair Astro Self-Centering Smartphone Telescope Adaptor. Credit: Altair Astro
The Altair Astro Self-Centering Smartphone Telescope Adaptor. Credit: Altair Astro

You’ll need to hold the phone squarely over the eyepiece and keep it steady without touching the telescope.

Once you’ve got this bit right, the tricky part is pressing the shutter button without moving the phone. Be prepared for some mediocre shots at first but persevere – they will get better.

Whether you hold your phone or use an adaptor, you’ll have to set your telescope up with an eyepiece, ideally one with a low to medium magnification to start with. 25mm is normally a good choice.

If you’re using a short focal length telescope with a low-power eyepiece, you should be able to get a shot of the Moon with the telescope on a fixed tripod.

Richard Matthews, Staffordshire. Richard says:
Richard Matthews captured this image from Staffordshire, UK, using a Samsung Galaxy J5 smartphone and a Celestron Travel Scope 70.

A driven and polar-aligned equatorial mount makes things easier, keeping the Moon centred and allowing you to use higher magnifications without your images suffering from motion blur.

Point the telescope at the Moon and focus the view through the eyepiece. With the Moon centred in view, hold your smartphone so it’s pointing squarely down the eyepiece. Try not to touch the eyepiece as this may move the telescope, nudging the Moon out of view.

Once you’ve got the Moon on the phone’s screen, check that the camera lens is looking squarely down the eyepiece.

If you get it right, the light from the eyepiece will be at its brightest and evenly spread as it enters the phone’s camera lens. If it’s slightly tilted, you’ll get a gradual degradation of brightness across the image.

A crescent Moon captured with the NightCap smartphone app. Credit: Paul Money
A crescent Moon captured with the NightCap smartphone app. Credit: Paul Money

When you’re all lined up, take the shot. Be gentle, though, as it’s easy to move the phone as you press the shutter button.

Some smartphone earphones can be used to operate the shutter via their in-line volume controls, while others offer voice control to prevent movement at this crucial moment.

For extra stability, a smartphone adaptor can take the strain out of holding your smartphone so are well worth your consideration.

Modern smartphone cameras are starting to offer more ways of altering exposure, often by photo apps. But the Moon should be bright enough to trigger your phone’s autoexposure functions so that the shot comes out correctly.

Use your smartphone to photograph the Moon: step-by-step

1 Prepare

Line up your telescope to photograph the Moon

Anticipate the Moon’s movement and point your telescope just ahead of it in the sky (you’ll take the shot when the Moon becomes centred). Focus the scope as accurately as you can, making sure the features on view are sharp.

2 Line up and shoot

Line your smartphone up with your telescope's eyepiece

Hold the phone squarely to the eyepiece until you get a bright blob on the screen. Carefully alter the distance between camera and eyepiece until the view focuses and isn’t overexposed. With the image on the screen, take the shot.

3 Use a smartphone adaptor

telescope smartphone holder

A smartphone adaptor takes the strain out of holding your phone and keeping it lined up. Once attached it can be adjusted until the smartphone lens is lined up with the eyepiece. Once aligned, you can take the shot.

How to photograph the crescent Moon and Earthshine

We’re going to show you how to capture a full-disc shot of the crescent Moon, along with its accompanying earthshine, using a DSLR camera.

The image we’re aiming for, like the ones below, depicts the Moon with a slim edge illuminated by light directly from the Sun and the rest of its face dimly lit by light reflecting off Earth.

Crescent moon and Earthshine by Ron G
Crescent moon and Earthshine by Ron G, captured with a Canon EOS 1200D DSLR camera and Tamron 70-300mm lens.

As is often the case with astrophotography targets, it involves more than simply pointing your camera up at the sky on the appropriate night and pressing the shutter release.

But before we explain how to catch a shot like this, it’s worth explaining how this elegant scene comes about.

At the point of new Moon, the lunar disc lines up with the Sun, while appearing slightly above or below it in the sky.

In this position, the Sun’s light is only able to reach the far side of the Moon directly, so the lunar face (the side seen by us on Earth) is bathed in darkness.

A thin crescent Moon exhibiting Earthshine setting over ESO’s Paranal Observatory in Chile, 27 October 2011. Credit: ESO/B. Tafreshi (twanight.org)
A thin crescent Moon exhibiting Earthshine setting over ESO’s Paranal Observatory in Chile, 27 October 2011. Credit: ESO/B. Tafreshi (twanight.org)

It’s not possible to see the Moon at this point in its monthly cycle as it is lost to the Sun’s glare. In the days following new Moon, the Moon appears to gradually separate from the Sun.

As the Moon slowly moves eastwards and its separation from the Sun increases, more of the Sun’s light is able to creep around its edges and we get to see more of its face illuminated with each passing night

This process is what gives us the Moon’s familiar phases, starting with the new Moon, followed by the crescent Moon, then the first quarter and the gibbous phases, before reaching the full Moon phase, when it’s opposite the Sun in the sky.

The sequence then plays out in reverse, before reaching the next new Moon, 29.5 days later.

The phases of the Moon. Þ The inner circle shows what the Moon looks like seen from above its north pole, while the outer circle shows the phase we see from Earth at that time. Credit: BBC Sky at Night Magazine
The phases of the Moon. The inner circle shows what the Moon looks like seen from above its north pole, while the outer circle shows the phase we see from Earth at that time. Credit: BBC Sky at Night Magazine

During this cycle we can often see the dimly illuminated portions of the Moon thanks to earthshine but the contrast between the portions is perhaps most dramatic during the crescent phase.

Imaging the earthshine is pretty straightforward: you use a longer exposure than for the crescent. This overexposes the crescent but will bring out detail on the earthshine-lit portion.

If you were to capture an image exposed for the crescent and another for the earthshine, you’d think that they would line up and produce a view similar to that which you’d see with the naked eye.

Earthshine, captured by Sarah and Simon Fisher.
Earthshine, captured by Sarah and Simon Fisher from Bromsgrove, Worcestershire, UK, with a Canon EOS 600D DSLR camera and 300mm lens.

But achieving this can be difficult. The human eye has an amazing dynamic range.

When you look at a thin crescent Moon with the glow of earthshine, it’s easy to take for granted just how much work your eyes are doing to see both the crescent and the earthshine so naturally.

A camera will struggle to see this contrast in one image: you’ll need to combine two exposures.

This technique, known as high-dynamic-range imaging, is a key astrophotographic skill  that can help with tricky targets such as this. The steps below will help you capture the necessary shots and blend them.

Photograph a crescent Moon, step-by-step

1 Attach your camera

Photograph crescent moon

Attach your DSLR to a telescope or lens with a focal length of at least 300mm – this will give you a large enough image to see the Moon’s disc with some detail on it. A telescope or lens with a focal length of around 1,000mm is ideal.

2 Set the ISO

Photograph crescent moon

Focus the camera as accurately as possible and set an ISO of 200-400 for the crescent shot. The exposure you’ll need will depend on your equipment. Take a test shot of 0.5 seconds and review the result.

3 Adjust exposure

Photograph crescent moon

Adjust the exposure so that the crescent comes out bright but without any white in it: check by looking at the image’s histogram on your DSLR. Take several shots increasing the exposure as you go until the image looks really  overexposed.

4 Layer up

Photograph crescent moon

Pick the best crescent shot and open it in Photoshop or GIMP. Then pick a sharp overexposed shot of the earthshine without too much glare from the crescent. Load it as a new layer and align the two – reduce the opacity of the upper layer to do this.

5 Magic masker

Photograph crescent moon

Make the upper layer opaque, then use the magic wand tool to select the crescent (adjust the tolerance if it’s not selecting it all). Create a layer mask. In Photoshop, copy the selection, hold down the alt key and click the layer mask button. 

6 Blur and blend

Photograph crescent moon

Use the eyedropper to sample the sky colour and use it to fill a layer between the shots. Set the new layer’s blend mode to Lighten and merge with the correctly exposed layer. Apply a Gaussian blur to the top layer’s mask and apply until  the images join.

Create a lunar mosaic photograph

Moon mosaic Hugh Bellamy, Aberkenfig, South Wales, 21 September 2019. Equipment: ZWO ASI 120MC camera, Sky-Watcher 254mm Newtonian, EQ6 Syntrek mount
Moon mosaic captured by Hugh Bellamy, Aberkenfig, South Wales, 21 September 2019 using a ZWO ASI 120MC camera, a Sky-Watcher 254mm Newtonian and an EQ6 Syntrek mount.

Before you can create a mosaic, you need detailed pictures. A mono, high frame rate camera is the best tool for the job, as it allows you to record a short video of each ‘pane’ (segment of the lunar surface) as an AVI file, the individual frames of which can be stacked into a still image.

If your camera doesn’t have an infrared-blocking filter built in, consider attaching an infrared-pass filter. Doing so can reduce the effects of poor seeing. Alternatively, try a red filter.

Moving across the lunar surface in overlapping panels is something that sounds easy, but there are pitfalls to avoid.

01 - Moon mosaic Craig Towell, Bristol, 21 September 2019 Equipment: Altair Astro GPCAM3 290M mono camera, Fullerscope 8.75
A Moon mosaic captured by Craig Towell, Bristol, UK, 21 September 2019 using an Altair Astro GPCAM3 290M mono camera, a Fullerscope 8.75″ f/7.5 Newtonian and a Sky-Watcher EQ6 mount.

The higher the magnification you use, for instance, the easier it is to get lost and miss a bit out; this is a common frustration when starting out.

It pays to be realistic in terms of image scale. If you’re experimenting with mosaics for the first time, capture a small number of panes to start with so you can get a feel for what’s what.

Image scale can be adjusted using optical amplifiers such as Barlow lenses, but aim to keep your telescope’s overall focal ratio somewhere between f/15 and f/45. Only go higher if the seeing gets really good.

A driven, equatorially mounted scope is ideal. Check your camera’s alignment by slewing in right ascension and rotating the camera so that features move parallel to the bottom edge of the frame. Finally, focus your setup.

There are various ways to move across the Moon, but imaging in horizontal strips with lots of overlap is best. A good overlap is typically 20-25%.

how to create a moon mosaic

When lining up your first pane, make a note of features close to the corners of the frame and use these as guides when positioning for the next one.

It’s good practice to image the strips in the same direction, moving back to the same starting side of the Moon between strips. Use features in the first strip of panes to make sure your vertical adjustment has plenty of overlap.

A rough sketch of the features in each frame can help. If you lose track, wind back to the last place you know you definitely imaged. It’s better to risk duplication than a gap!

Point your telescope at the brightest part of the Moon and adjust your camera’s gain and exposure so peak saturation is around 90%.

You should now be able to leave this alone. You can adjust the exposure levels for each frame if you want, but this is more time consuming and requires greater effort when it comes to stitching your panes together.

The Moon - 09th May 2017, by Chris Campbell.
A Moon mosaic captured on 9 May 2017 by Chris Campbell.

The advantage is less noise in dark regions and extra navigational detail when crossing seemingly featureless areas, such as the lunar seas. For more on this, read our guide on how to remove noise from your astrophotos of the Moon.

What you’ll need to do during a long mosaicing run is refocus often. This is essential to prevent defocusing caused by temperature variations.

A 12V camping hairdryer is also invaluable for removing moisture from dewed-up optics during long runs. For more on this, read our guide on how to stop dew forming on your telescope.

Two final tips: mosaic captures typically take up lots of computer hard drive space, so make sure you have plenty free. Plan ahead to make sure the Moon doesn’t disappear behind by a tree or rooftop part of the way through your imaging session.

Below we’ll show you how to process your panes and create your Moon mosaic. For more info on this, read our dedicated guide to creating a Moon mosaic.

Stack your moon images

A stacked image of a partial eclipse of the Moon, 10 January 2020. Credit: Dave Eagle
A stacked image of a partial eclipse of the Moon, 10 January 2020. Credit: Dave Eagle

The next step is to process each AVI file to produce one still image, ready for assembly into the final mosaic. For a large mosaic made with many panes this can be a daunting and tedious task, but there are ways to speed things up.

The first step is to analyse, register and stack the frames captured in each AVI file. There are various good free programs that can do this for you, including RegiStax, AutoStakkert and AviStack.

We’ll be using AviStack for the bulk of the processing and RegiStax to perform wavelet sharpening on the results. For more on this, read our guide to wavelets in RegiStax or how to stack DSLR images of the Moon.

The analysis step determines the quality of each still frame and then ranks them in order of how good they are. A user-set quality threshold then determines how many of the frames are used.

The frames that are above the threshold are ‘registered’ (aligned) to one another. These are then ‘stacked’ (averaged) to produce a final image.

Quality analysis determines which frames will give you the best results. Higher quality potentially means more noise

The higher the quality threshold, the fewer frames will ultimately go into the stack. This will result in the sharpest output, but with fewer frames to average, noise is more noticeable.

Set the quality threshold lower and there will be more frames to average, resulting in a smoother, less noisy result. But using lower-quality frames reduces overall image sharpness.

It’s a good idea to perform a number of test runs using AviStack if you’re not familiar with the program.

There are a lot of settings that can be configured. These are shown in a separate window and can be viewed by expanding the tree list.

Moon mosaic, by David de Cuevas.
A 12-frame Moon mosaic, by David de Cuevas, captured from Treize Vents, France, with a ZAO ASI 120MC camera and a 150/750 Newtonian.

Double clicking on a parameter section, for example ‘Frame selection’, will bring up a control window allowing you to adjust the settings. You can toggle between automatic and manual processing by clicking on the gear icon below the section header.

Setting the toggle to ‘Automatic processing’ lets AviStack make decisions for you, which can be useful if you’re not sure what you’re doing.

AviStack has a great batch-processing mode that can work on large numbers of AVI files unattended. The end result is a single distilled image for each AVI capture.

Various output formats are available, but we recommend PNG as this is a lossless format that many editing programs and file viewers can easily display.

Other lossless files can be used, but how easy they are to view and manipulate varies. Avoid formats such as JPEG that use ‘lossy’ compression – these discard data to make files smaller.

Mosaic of a 35%-lit Moon, by Jarrod Bennett.
Mosaic of a 35%-lit Moon, by Jarrod Bennett, captured from Mutxamel, Spain, using a ZWO ASI120mm camera and a Sky-Watcher 150PL.

Following the step-by-step guide below, the initial process delivers results with no sharpening. To the eye these will look blurred, so to address this we’ll apply the excellent wavelet sharpening function in RegiStax.

Sharpening lunar images needs to be done with great care – it’s easy to get carried away and push it too far. If in doubt, leave the image up on your computer screen and walk away from it for a while.

When you come back, your initial reaction will be a good indicator as to whether you’ve taken things too far. If you’re creating your mosaic at low magnification, a gentle tweak on the first slider is all that’s normally required.

The most exciting part of mosaicing is building the final image. There are free programs that can do this automatically, such as Microsoft’s Image Composite Editor (ICE).

Building the mosaic manually is more time-consuming, but ultimately a more rewarding experience.

Doing it yourself can also help to avoid the errors that can creep in when you let automated programs carry out the process.

Process your lunar image, step-by-step

1 Load

Processing panes AviStack

Load a single AVI into AviStack. If you’re processing it manually, select Settings > Processing > All Manual from the menu. If not, click on All Automatic. Expand the Save Stacked Image section and check Manual processing is set. Click on Automatic processing if shown. Expand the Post processing section and select Manual processing. The four options below should be deselected.

2 Save

Processing panes AviStack

Click on Process File. In the Save stacked image window (right) select PNG as the file type and pick a folder to save it to. Make sure Save Parameters is ticked before you save. Hit Cancel when the Post processing window appears. Check if the result needs wavelet sharpening (see step 5). If not, repeat and adjust parameter settings in a manual run using the help options to assist.

3 Batch Process

Processing panes AviStack

That’s your first processed file complete. The settings for this file will be used for the batch processing run. Click Add Movies and select all of the files to be processed, then click Open. Finally, click Batch processing and let the program run through each file, saving the results as per the settings you chose in the save stacked image box in the previous step.

4 Keep the originals?

Processing panes AviStack

Once you have all the AviStack-processed PNG results, copy them to a new folder called ‘Wavelet-sharpened’. These are the files you’ll edit in RegiStax, but leaving the originals untouched means you can rework them if new techniques become available. Once you have your final results, the originals can be discarded if you need the disk space.

5 Sharpen

Processing panes AviStack

Run RegiStax and click Select. Change Files of Type to match the format of the processed images (in this example, PNG). Load the first image. With the Wavelet tab selected, click on the preview buttons to see which details will change. Use the slider that shows the finest detail that isn’t just noise grain. Adjust the sliders to sharpen the image to taste.

6 Begin the mosaic

Processing panes AviStack

Wavelet sharpen all of the images, saving each when done. Next, load the first image into a program such as Photoshop or GIMP and crop any unwanted edge artefacts. Estimate how big the canvas needs to be to hold all the panes and resize it. Don’t worry if you get it wrong as you can adjust it later. Select a black background for the new canvas.

Building your moon mosaic manually

Þ Align your panes by zooming in and nudging them into place with the arrow keys

If you followed our step-by-step guide above, your base image will contain a single, finished pane and your canvas will be big enough to take the rest. Load the next frame in the sequence and draw a selection box slightly smaller than the frame edge.

Apply a 5-10 pixel feather to the selection. Copy the selection and paste it into the base image.

Use the arrow keys to align the pane with the lower image. Toggling the visibility of the pane on and off will help you align it accurately. 

Small variations in tone between the pasted and base images can normally be dealt with by gently tweaking the curves tool (see our guide to Photoshop Levels and Curves). You should apply the adjustment to the centre of the curve.

For larger variations, raise or drop the brightness of the image first to get it closer to where you want it, then use the curves tool to carry out fine adjustments.

The feathered edges of the pasted image pane should make any straight edges hard to see.

If some are still obvious, set the eraser tool to 10% and gently rub it over any visible joins; this should hide them.

Þ You may need to adjust brightness and contrast to blend adjacent panes together
You may need to adjust brightness and contrast to blend adjacent panes together

For very large mosaics that stretch your computer’s memory, assemble a batch of panes and then save the layered image to a file called ‘mosaic-001’.

Flatten the image and continue loading with the next set of frames. When you get to a similar stage as before, save as ‘mosaic-002’ and flatten.

Repeat until the whole mosaic is complete. Doing this means you can go back and address any major problems.

When you’re finished, flatten the image and save it with a file name of your choice. A gentle tweak of brightness or contrast, or a small adjustment using the levels and curves tools, can help to finish off your masterpiece.

It takes a bit of work to build such a mosaic manually but once it’s done, the feeling of satisfaction will be immense…unless you’ve missed a bit of course!

Have you managed to capture a beautiful image of the Moon? We’d love to see it! Send it to us via contactus@skyatnightmagazine.com or get in touch on Facebook, Twitter and Instagram.

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Will Gater is an astronomer and author who presents live astronomy shows. Pete Lawrence is an astrophotography expert and presenter of The Sky at Night.