A Shot in the Dark: Pointing My Camera Skyward at Night

First off, let me say I’m not an astrophotographer, I don’t even play one on TV. Heck, I don’t even own a telescope. In fact if you’re a serious astrophotographer this is probably not for you.

On a lark I thought I’d point one of my faster lenses towards the heavens and see what I could get. Much to my surprise, I got more than I thought I would, even with only a meager 150mm lens.

Before I go any further, let me explain a little bit about the conditions here. I live in the middle of the South Florida tri-county urban sprawl, according to light pollution maps from Clear Dark Sky.com this is an 80 mile long by 18 mile wide swath of Bortle class-9 light pollution. The Bortle scale definition of Class 9 skies is below.

Sky is brilliantly lit with many stars forming constellations invisible and many weaker constellations invisible; aside from Pleiades, no Messier object is visible to the naked eye; only objects to provide fairly pleasant views are the Moon, the Planets, and a few of the brightest star clusters.

With the naked eye, I can generally make out magnitude 3-4 stars a pair of 8×50 binoculars helps a little but not much. Digital capture tends to get me a lot more , I can image stars as faint as magnitude 7.5 even on less than fantastic nights.

What to Shoot?

The Moon

The moon is obvious. It’s bright enough that it takes actual cloud cover to obscure it (use the sunny-11 rule (1/ISO, f/11) as a starting point) and large enough that you can get some detail with reasonably priced lenses in the 300-400mm.

The image above is cropped form the a shot made with a 400mm lens on an EOS-1D Mark 3. A crop camera is even better (i.e. Canon’s Rebels or x0D series or Nikon’s D300) thanks to the higher density sensors and longer effective focal length. I have images made with a Canon 70-300 IS on a 40D that don’t look much different than the one above.

Though nice, and with enough shots one could piece together a nice moon phase chart (a project I’ve been meaning to work on actually), the moon gets old rather quickly.

Planets

The planets are typically the next brightest thing in the sky. Though with out a telescope or a very long lens–which generally brings us back to needing a tracking mount–you don’t get much more than points of light and of all the planets. Jupiter is a notable exception and worth taking a stab at at least.

The images below were cropped from a single frames taken with a 150mm f/2.8 lens (left) and a 400mm f/5.6 lens (right) over two nights. Both exposures were a half second long with the lens wide open (f/2.8 on the left, f/5.6 on the right) at ISO 400.

You don’t get much detail, but you can watch orbits of the Jovian moons progress over time, which is marginally more interesting than looking at our moon. (Click the images to see larger versions.)

What about the other planets?

I haven’t tried imaging much more than Jupiter directly yet.

Venus, though bright lacks a moon removing a lot of appeal when you can’t resolve more than just a point of light. Most of the images I’ve made that have Venus in it have been sunsets where Venus shows up as a bright dot in the sky.

Mars, though it has moons, is very small and not that bright and it’s moons are very dim and relatively close.

I doubt Saturn will work very well at all, though. I won’t get a chance to try until January, then again the seeing will be better then too. Saturn itself is bright enough (mag ~1.4) to be imaged but it’s moons aren’t very bright (mag 9.6 max). Further the great distance to Saturn means  and the moons will be very close to the planet and I likely don’t have enough magnification to do anything about that.

Something else entirely

The last thing I’ve turned my camera towards is star clusters. Notably the Pleiades. However, with the amount of light pollution, none of the nebulae are visible, so they simply become a bunch of stars.

However, the stars themselves are readily visible and with digital capture and stacking, you can extract quite a few that aren’t visible with the naked eye.

Given the local conditions, I have never seen any of the Messier objects other than M45 (the Pleiades).