Is Magic Lantern changing the world? Yes!
Here’s another example of a use for Magic Lantern RAW video that just astounded me.
While in itself, it isn’t “exciting” videofor most people, for those who are into astronomy, an occulation of objects is indeed fascinating (I was very into astronomy as a kid and watched many of these events).
When I saw this video, I was so surprised by the dynamic range – the Moon is very bright and Saturn isn’t – so I had to ask Colin Legg how he did it! He graciously sent planet5D some background info.
It is especially significant if you understand the difficulty in making this video (again, I know it isn’t horribly exciting or cinematic), not only the relative rarity of it, but how difficult it is do shoot… so I want you to specifically see the ‘challenges’ section below.
From Colin Legg:
We have waited 10 years for a Saturn/Moon occultation event in Australia. The Moon orbits the Earth at an angle with respect to the Sun and planets and this slowly changes with time. 2014/2015 are good years for occultations as the angles converge. We are lucky to have 4 Saturn events in Western Australia this year.
The first, February 22nd, was a daylight occultation, with first contact occurring right on dawn in WA. I have wanted to video this event for years. The challenge is to capture sharp well exposed images of both the Moon and Saturn as they converge. Saturn is tiny compared to the Moon due to it’s much larger distance away. So you need a fairly good telescope to nicely capture both the planet and it’s rings.
Moon Saturn Occultation
Captured from Perth, Western Australia, just on dawn.
Equipment: Celestron C8, f/10, prime focus. Canon 5D2, running Magic Lantern RAW video firmware in 3x crop mode @ 1880 x 1056 resolution. 1/60 sec exposure, ISO 200, 10 fps.
Thanks to Alex Cherney for the original heads up
1. Stability: At 2000 mm focal length you need a solid tripod, well balanced camera and no wind. Camera mirror slap and shutter shake are both sources of unwanted movement.
2. Dynamic Range: The limb of the Moon is quite a bit brighter than Saturn. A 14 bit, DSLR has adequate range, 8 bit is too narrow.
3. Resolution and Scale. Smaller pixels are preferred to capture the fine details. At least full HD (or close) to include as much of the Moon’s limb as possible.
The 1st requirement is best served by video capture. Electronic shutter eliminates camera shake. The 2nd and 3rd are best served by classic DSLR still capture. What to do?
1. Hire a 1Dc or Red. Both meet all requirements, but are quite expensive to hire and not readily available in WA. Cost can exceed $400 for one day hire.
2. Install Magic Lattern alpha video firmware on 5D2, and shoot in 3x crop mode video. Video solves (1), Raw solves (2), 3x crop solves (3). And it costs nothing (extra) !
Equipment: Celestron C8, 2000 mm, f/10, prime focus. Canon EOS 5D Mark II, running Magic Lantern RAW video firmware in 3x crop mode @ 1880 x 1056 resolution. 1/60 sec exposure, ISO 200, 10 fps.
Other astronomical events I’ve captured in the past couple of years
(cover photo credit: snap from the video)