It’s the start of a new year and already we have had our ‘super moon’ of 2018 in the skies; on the 1st January 2018, the moon reached its perigee – the point in its orbit when it is closest to Earth. This creates a phenomena where the moon near the horizon appears bigger than normal (it isn’t actually much bigger; the effect is an optical illusion).
Luckily, I had clear skies on New Year’s Day, when the moon was at 100%, and so set about shooting video to process into a moon shot.
I tried this earlier last year with some success but the image ended up with ghosting artifacts which really annoy me so I wanted a chance to reshoot and try a new approach.
I used my Skywatcher 80ED scope with an Altair Hypercam IMX178c. I use this camera for planetary and lunar work and find it is excellent for both. For capture, I used the current beta of Sharpcap which has a few cool features. Firstly, Sharpcap helps automate focusing which is a real help when seeing isn’t great – focusing on the moon, especially in urban areas, is difficult as atmospheric conditions cause the image to shift in and out of focus. Sharpcap has a feature that helps average focusing across a number of frames and moves the focuser through a series of steps. I tend to run this a few times to account for focuser backlash and to find the sweet spot for my focus.
Once focused, then the real magic happens. Sharpcap beta has a ‘seeing monitor’ function where you can select a lower limit on seeing conditions based on a graph that is produced as the camera gathers frames. You can also set a frame count so that your video will contain much higher quality frames so will produce cleaner stacks later on.
Why video? Sheer force of numbers. I can’t quite fit the moon onto my sensor using the 80ED so I need to shoot two images and then merge them together. Each ‘image’ is the result of a stack in Autostakkert!3 and the stacks are made from .ser video files of 5,000 frames each! When I stack, I select the top 5% only to make sure that my image is as good as it can be, given the conditions I shoot under.
Once stacked, I ended up with two .TIFF files that need combining. I use Image Composite Editor, a free (!!) program from Microsoft that works seamlessly (sorry!) to create a composite image.
Until now, I would then load the image into Registax and play with the voodoo wavelets until something useful appeared, but I had issues with the final image that always seemed to have horizontal and vertical lines embedded into it, and which I would have to then spend time cloning out in Photoshop.
No longer! I discovered a plug in by Astra Image that provides brilliant sharpening filters for Photoshop that are, in my experience, far superior to Registax.
I processed the composite image using the filters before using three saturation adjustment layers (60%, 30% & 15%) then creating contrast using curves. The final image shows the colours of the mineral content on the surface of the moon and creates, in my opinion, a far more interesting image than the more common grey / mono images.
I am much happier with this image when compared to the one I processed last October. The detail is stronger and the focus is much tighter. Next, I plan to use my 8″ reflector with a 2x Barlow to draw out some more surface detail of craters.
To help learn the Moon’s features, I found a helpful website that identifies areas you hover over.
Higher resolution on my Astrobin account