How to image the Moon
Capture our nearest celestial neighbour in all its glory with the help of the second part of our astro imaging masterclass. In it, we show you how to capture great pictures of the Moon using a telescope, a mount and a webcam, as well as providing essential information about how best to use that equipment, and how to tweak your resulting images with photo editing software.
You too can take lunar images like this. Here's where we show you how
Capture our nearest celestial neighbour in all its glory with the second part of our astro imaging masterclass
With its ever-changing face and myriad of interesting features, the Moon is a truly wonderful target for astrophotographers of all abilities. But for all its obviousness and brightness, it takes considerable attention to detail to capture top-quality images of our natural satellite. Here, we show you how to do it.
The kit that you’ll need to begin snapping the Moon
Anyone with a telescope and a basic camera can take a good image of the Moon. But it’s best to use a webcam or CCD camera to take lunar images. These cameras are capable of taking short videos, consisting of many frames per second, which is why specialised lunar and planetary CCD cameras are often referred to as ‘high frame-rate’ cameras. A webcam, like the popular Philips SPC880NC, costs between £20 and £40, while specialist CCD cameras for lunar imaging, like the Imaging Source DFK 21AU04.AS, start at roughly £280.
You can use any kind of scope with these cameras; however, large-aperture Schmidt-Cassegrain and Maksutov-Cassegrain telescopes are popular choices with top lunar astrophotographers. This is because their longer focal lengths are well suited to ‘close-up’ imaging of the Moon, and compared to a high-quality refractor, you get a much larger aperture for your money.
Accessories for lunar imaging
To attach a webcam to the eyepiece holder on your scope you’ll need a ‘nosepiece’ adaptor. They can be bought from all good astronomy shops for between £12 and £25. You’ll probably need to remove the webcam’s lens first though, before screwing the nosepiece in place.
If you are using a monochromatic planetary camera you might find it useful to use a red filter when capturing lunar images. Using one can help produce a crisper final image. A red filter typically costs between £20 and £70.
For detailed webcam close-ups of the lunar surface and its craters, a Barlow lens is a must. It increases the focal length and the magnification of your telescope system by typically two or three times. A Barlow will cost you between £40 and £120.
Dramatic lunar features to capture
This grand lunar crater is a great target if you’re trying to push your equipment to its limit. See how many of the small craterlets you can capture on the crater floor.
One of the most stunning craters on the Moon, Copernicus makes for a wonderful imaging target. See if you can capture its magnificent terraced walls.
This impressive 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.
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.
This dramatic valley cuts straight through the lunar Alps. The challenge with this object is to see if you can capture the elusive rille that runs right the way through it.
Crater Tycho is famously surrounded by bright ejecta rays – brighter material that was flung out by the asteroid impact that formed the crater itself. It has a huge central peak.
Make a lunar mosaic to show the Moon at its most majestic
Most high-resolution images of the Moon’s surface aren’t in fact made from a single image, but a mosaic of several smaller panes. Whether it’s a really detailed close-up of a crater or an enormous mosaic covering the entire lunar disc, chances are it was made by carefully stitching together many smaller overlapping images. Learning how to capture and process a mosaic is a crucial part of lunar astrophotography.
The majority, if not all, of the best lunar images are taken with either a webcam or a dedicated lunar and planetary CCD camera. You’ll need a laptop with capture software installed for this type of astro imaging, as well as a telescope with a mount that’s capable of accurately tracking the Moon.
The first step is to take the individual AVI videos. Remember to create a slight overlap between adjacent areas, which will help later with the processing. If you’re making a mosaic of the whole disc, check you’ve covered the entire Moon. You don’t want any gaps!
Next, process the videos you’ve captured to produce the individual panes for the mosaic. You’ll need to stack them in a program like Registax. Once you have the individual panes you can then stitch them together to create a mosaic.
Watch the software walkthrough video below to see how the individual panes are stitched together in a graphics editing program like Photoshop.