Trampas Peak Eclipse
The full “Snow Moon” balances on Trampas Peak (12,175′) during a lunar eclipse, Sangre de Cristo Mountains, Northern New Mexico. The “Snow Moon“, also known as the “Hunger Moon“, is the Native American name of the full moon in February, the time of year when the heaviest snows fall and winter life is often difficult. This is a single, real, image (not a composite or “photoshopped”).
The Story Behind the Photo
A full moon during an eclipse was about to rise over the summit of Trampas Peak (12,175 ‘) in the Sangre de Cristo Mountains of New Mexico. If I did my calculations correctly my tripod was in the right place for me to photograph the moon sitting on the summit of Trampas Peak. One small problem though, clouds! Read More
My biggest nemesis for moon photography are clouds. Earlier in the day a thin veil of clouds started to cover the cold snowy mountains. All it takes is a very thin layer of clouds to scatter the moon light and lose detail on the surface of the moon. Sure enough the clouds were back to tease me.
As I watched the orange moon rise in the indigo sky the clouds were moving enough that I might get lucky. As if the scene was choreographed the clouds thinned out just enough to see the moon perched on top of Trampas Peak. The thin layers of clouds lit up with the warm colors of the orange moon. A faint sky glow backlit the high altitude snowfields on Trampas Peak.
The light played out perfectly for me. This is what I love about landscape photography. Planning and preparation does help a great deal, however in the end you are not exactly sure how the lighting will look. You have to do the best with what you are given.
What is a Penumbral Lunar Eclipse?
When the full moon rises in the side lobes of the Earth’s shadow (known as the penumbra ) a penumbral eclipse occurs. Penumbral eclipses are hard to distinguish as the sunlight on the moon is only slightly diminished to that of a regular full moon.Read More
The umbra, penumbra, and antnumbra regions of Earth’s shadow are shown here.
(Photo courtesy of By Sagredo [Public domain], via Wikimedia Commons)
Why does the moon look so big in the photo?
How do they do that — you know make the moon look so big in the photo?
Frequently I am asked if a photograph is “photoshopped”. I understand the motivation behind this question since photography today has many examples where part of one image is artificially added to the original image on the computer, in Adobe Photoshop, or other image processing software. The “technical” term these days is a “composite” image.
The moon photographs I present are not composites. My photographs are single images where the moon is in the exact position in the frame was when I took the image, and the size I saw it through my lens. So why then does the moon look so big?Read More
This is best understood by comparing angular size of the moon compared to the angular field of view (AFOV) of the lens used. The moon is approximately 0.5 degrees in size. Long focal length lenses have a small AFOV. For example, my 600 mm lens has an AFOV of (3.4 deg, 2.3 deg) in the (horizontal, vertical) direction. A moon photographed with a long focal lens will look big since the moon’s angular size (0.5 degrees) is a large fraction of the AFOV of the scene captured by the lens.
Conversely, using a wide angle lens the moon appears as a small dot in the night sky since the angular field of view of the scene captured is wide. A 24 mm focal length lens has an AFOV of (73.7 deg, 53.1 deg) in the (horizontal, vertical) dimensions. The 0.5 degree moon is tiny compared to the horizontal width of 73.7 degrees.
The angular size of the moon is 0.5 degrees, whether it is on the horizon or high in the sky (outside of a tiny correction for atmospheric refraction). The moon is also 0.5 degrees in size when looking through a wide angle lens, or a telephoto lens. It looks very big when looking at it through a telephoto lens since the angular field of view (AFOV) of the telephoto lens is small.
The cone of visual attention of the human eye has an angular field of view of about 55 degrees (equivalent of a 43 mm focal length lens). Our eyes can notice movement and broad shapes over a total angular field fo view of 160 degrees though.