Planets and the Moon

Images of Solar System bodies benefit from stacking images together

Imaging the Moon can be achieved with just a DSLR, lens and tripod. As you start out you’ll be pleased with the details from a single frame, after making minor adjustments in Photoshop. For the best level of detail, however, you’ll need to attach your camera to a scope with a T-ring and adaptor to give a longer focal length. For planetary imaging, the longer the focal length of your telescope, the better.

To get sharper lunar details you can stack multiple DSLR images, or you can use a planetary camera. With its high frame rate, a planetary camera will cut through atmospheric turbulence more effectively than a DLSR, but either is a good choice for the Moon. For planetary imaging however, a planetary camera is best for capturing detail, and you’ll need a laptop to control it.

For either type of camera the best program to use for stacking your lunar or planetary images is AutoStakkert!. This freeware assesses which files to keep or discard from a stack. To stack, open the software, upload and select the ‘Image Stabilization’ option, either ‘Surface’ or ‘Planet’ (depending on whether the Moon is completely in the field of view). The ‘Analyze’ function will show graphically which frames provide the best data, and you can opt to stack a percentage accordingly.

Once stacked, the next piece of software you’ll need for overhauling your lunar or planetary image is RegiStax. Its important setting is the ‘Wavelets’ function (see figure 4), as this sharpens and emphasises detail. Further tweaks can be made in Photoshop, by using the ‘Brightness/Contrast’ and ‘Hue/Saturation’ settings.

For lunar photography, many opt to make a mosaic, particularly if the telescope you’ve used allows detailed crater images (see figure 5). It’s important to get the order of the software right if you’re stitching frames together. First stack your images in AutoStakkert!, then upload them to ICE to create the mosaic, and upload the full mosaic image into RegiStax. This ensures that you sharpen each element within your mosaic evenly and stops the final mosaic looking ‘patchy’.

▲ Figure 4: once your lunar image has been stacked you can use the ‘Wavelets’ function in RegiStax to carefully emphasise surface detail

▶ Far left: an image of Jupiter taken with a CCD camera and processed from stacking the best 600 of 1,100 frames in RegiStax; Left: a mosaic of the waning Moon made of 67 panes processed in RegiStax, with further contrast processing in Photoshop

▲ Figure 5: you can create a stunning Moon mosaic, but make sure you use the software in the correct order