The Moon, up close and personal: Take detailed photos of the Moon with your phone!
When we don’t have visitors, we spend a lot of time making very long exposure images of deep-sky objects: faint nebulae, galaxies and so on. You can see many of the results on our website. But recently, while making another long-exposure image, I was looking at the Moon with our visual telescope (the Meade LX200-GPS 12-inch). I was so impressed with the view that I decided to try putting my iPhone to the eyepiece to see what would happen.
I was stunned at the result.
This shows the Moon’s south polar regions, with a huge crated called Clavius prominent near the bottom, a well-formed crater with deep shadows above it, called Tycho, and near the top-centre a long cliff casting a shadow, called the Straight Wall.
To be fair, I didn’t just hold it there; I used a small device we bought years ago at an astronomy show. It’s called a FoneMate [link: http://www.televue.com/engine/TV3b_page.asp?id=73&Tab=_phone ]
The FoneMate allows me to fix the phone securely to the eyepiece. Then I can just use the iPhone’s own picture-taking controls to take the shot. If you visit the observatory with a suitable object in view (so far I’ve only tried it with the Moon), you can try it for yourself!
I found out, after the first evening, that the iPhone camera clips highlights, as we can see in this image of the big crater, with a flat floor, called Plato.
I also found that the phone keeps trying to focus, even though the scope is already focused. In fact I wasted some time trying to adjust the scope focus while the camera was adjusting itself.
Nevertheless, I was quite pleased with this first experiment.
So the next night I learned how to lock both the focus and the exposure on the phone, and how to reduce the exposure to help with the highlights which were overexposed. I found the results much better, as perhaps you can see in this next photo.
This shows a large crater called Copernicus, and some others: a large one with a flat floor near the top of the image, called Archimedes, and the third-largest in the image, at the end of a mountain range, called Eratosthenes.
As you can see, there is a rule that Lunar craters are named after scientists or philosophers.
Ranges of mountains, on the other hand, are named after terrestrial mountain ranges: the mountains leading to Eratosthenes are called the Apennines, while the mountains around Plato in the earlier picture are the Alps (and the large cleft to the right of Plato is called the Alpine Valley).
I should add that I have flipped these images to correct for their original mirror image, and then rotated them 180° to correct for the upside-down view in a telescope. I’ll explain the reason for these effects in a later blog.
In the meantime, here are a few more images from my first night’s experiment:
A view of the Mare Imbrium, from Plato to Eratosthenes, showing the Alpsand the Apennines.
I should add here that the large, flattish, darker areas on the face of the Moon were originally thought to really be seas and oceans (obviously before telescopes were as good as they are now). So they were given appropriate names, in Latin. Mare Imbrium, rather poetically means the Sea of Showers. The famous Tranquility Base established by Apollo 11, was in the Mare Tranquillitatis, the Sea of Tranquility.
In reality they are enormous craters filled with solidified lava which welled up after the impacts. Mare Imbrium is, in fact, one of the larger craters in the Solar System and was formed during a period known as the “Late Heavy Bombardment” around 4 billion years ago. The impacting body is thought to have had a diameter of about 250 km.
The large crater at the centre of this image is called Ptolomaeus, and is linked to the south to another large crater called Alphonsus. And just to the south of that is a well-formed crater called Arzachel. To the right of Ptolomaeusis, another large crater called Albategnius.
Stand by for updates as I (hopefully) improve my iPhone camera technique!