Anatomy of a Photo - DigitalQuixote

Photos

Prelude

It’s my daughter’s fault, in a manner of speaking. It’s her fault, to a degree. She sends me a link to a photo of the Milky Way setting over Mount Rainier in Washington State. It’s the Milky Way over the U.S. of A.

It was taken from a vantage point I know well … possibly just a few feet from a lightly traveled road near the Sunrise visitor center on the Northeastern shoulder of this great mountain. We should try that, I say. We’ll have to wait ‘til summer.
It’s her fault, but she comes to it naturally. I’m the one who would drag her out of bed at 2:00 in the morning to go out and watch meteors from the back deck. My wife and I would drag her and her brother out for a night walk at Rainier to look at the stars. She comes by it naturally and we have another shared interest – photography.

Preamble

A year later, more or less, I am having breakfast with a long time friend. We’ll call him Rudy because that’s his name. I’ve known Rudy for 33 years. We worked together at Accenture in the beginning, drifted apart and back together from time to time. He and I share interests in photography, computers, and travel and sometimes think along similar lines.

I describe my thoughts about shooting at Rainier. I talk about roughly when and where. How it might be interesting to shoot it together. What sort of equipment we’d use. The sort of post processing that would be good. The challenges we’d face getting a killer shot. He grows more interested by the minute and so do I. But as they say, I think I had him at ‘hello.’

Interlude

I’m reading my email a few days later and here’s one from Rudy. It has a couple of images, screen shots of a simulated night sky over Rainier, and he says, “We need to do this in early July or early August.” No moon, he says. Milky Way in just the right spot, he says. Predictably good weather, he says. We agree to do some detailed planning at our next breakfast in late June.

Breakfast of Champions

Breakfast is at Palomino in Bellevue. We look like a couple of candidates for Electronics Anonymous. I have my phone, my tablet and my laptop. So does Rudy. Using The Photographer’s Ephemeris, we place a pin on a map of the area where we want to shoot. We dial in the date, nominally August 8th. We can now see that sunset is at 8:28. Sunrise is at 5:56 the next day. No moon. We ought to have 4 perfectly dark hours to shoot between 11:30 and 3:30 but there’s a little guesswork going on here.

But will the Milky Way be visible? Will it be in the right place? It looks like the summit of Rainier is southwest of where we want to shoot. So we pull up Sky Safari, dial in August 8th at midnight, say. Point it southwest. And right there in front of us is Rainier. The Milky Way is up but it’s in the wrong place. We dial time forward and backward until 1:23 AM. There is the Milky Way shooting straight up from the Rainier summit.

But we’re eyeballing compass bearings and shooting locations.

Angles and Demons

Yeah, I meant angles, not angels.

I’m troubled by something else. Since Rainier is at 14,000 feet and change and we’ll be shooting from 6,400 feet or so, it will stick up in the sky. Will it block the best part of the Milky Way?

One way to tell is to take a scouting trip, shoot the mountain with the camera perfectly level and ‘see’ how far it sticks up. This will also let me scout other possible shooting locations. Off I go.

I get to Rainier and there’s a cloud layer about 12,500 feet. Vicious looking black clouds swirl around the summit which I will never see the day of my scouting expedition. I shoot it anyway and I can see the summit of Little Tahoma. I can infer a lot about angles but my inferences aren’t very precise.

When I entered the park, I received a detailed map of the area. At home, I pull out ruler and protractor and measure angles and distances. This pretty much confirms our southwest orientation. I measure the distance from our shooting location to the summit. I know the altitude difference. I dust off my high school trig and calculate the angle: Tan(A) = a/b. I have a bad moment because the result is expressed in radians. When I remember, I convert to degrees. A turns out to be a little over 12 degrees above the horizon.

Back to Sky Safari and I find a star about 12 degrees above the horizon through trial and error. Everything looks great.

I love the Internet

I recognize obsession when I see it.

I am bothered about relatively imprecise measures of distance from a shooting location to the summit. There must be a way to calculate the distance if I knew the latitude and longitude of both points – something the Photographer’s Ephemeris will tell me. The math is HARD. But I find a calculator on the Internet that gives me the distance and a bonus, the compass bearing.

And I want to get a better fix on our shooting window. Astronomical Twilight ends when the sun is 18 degrees below the horizon and begins the next morning when it is also 18 degrees below the (other) horizon. Between these times, sunlight diffused through the atmosphere is less bright than starlight. I find another neat little calculator on the Internet that tells me by month and day, at any location on earth, the beginning and end of Astronomical Twilight. On August 8th, we have a window between 10:40 and 3:51. So all is good.

Did I mention I love the Internet?


But It’s Not About the Planning

Photography is like sex; planning is fun but it’s not the goal. It’s time to put all this math to work in the field. Rudy and I will shoot this in August – but for today, another friend and I will shoot it. We’ll call him JB because that’s what he likes to be called.


After a two-hour drive JB and I arrive on Mt. Rainier at about 7:30 PM July 13, 2013. This is good because it lets us review possible shooting locations and choose one before it gets dark. But it takes a long time to get dark; sunset at 9:00; the end of astronomical twilight at 11:30. So I shoot some ‘golden hour’ shots of Rainier.

About 11:30 I get serious about shooting and run into all kinds of practical problems. None defeat me, but all pose an obstacle to my objective.

The first proves the most difficult to solve. My camera has a great auto focus system but it works poorly in the dark. So it’s up to me to set manual focus on my camera. This is surprisingly tricky. I want the stars pin sharp and it’s tempting to spin the focus ring all the way to the infinity end of its travel. Turns out that too far and the stars fuzz out. Back off too much and I go past perfect to where they fuzz out again. It’s 42 degrees and I’m shivering cold so precise adjustment isn’t as easy as it sounds. I’m wearing a headlamp with a red light to preserve my night vision but it’s just barely bright enough to see the dial. Eventually I get it.

The next is balancing my camera’s ISO, aperture and shutter speed, which I am setting manually. If ISO is too low, it won’t record the starlight I came to capture; too high and the noise that high ISO generates will spoil the image. Aperture is wide open, f/2.8 with the lens I’m using. No decision there. If shutter speed is too fast for the ISO, the camera won’t record the starlight I’m after. Too slow and long exposure noise will spoil the image. Much of the shooting tonight is trying different ISO settings between 1,600 (mostly too low) and 5,000 (somewhat noisy but not a disaster). Then for each of these settings, trying different shutter speeds between 13 seconds (too fast to be much use) and 30 seconds (to long to avoid star trails.) 4,000 – 5,000 and 20 – 30 seconds seems about right depending on how much sky is in the scene.

Lessons for the Future

Rudy and I are going to do this in August when the Milky Way will be a bit further to the west.

Lessons for that shoot – what to change: 1) Dress more warmly; 2) Take only two lenses to reduce carry weight; 3) Get higher on the mountain. Lessons for that shoot – what not to change: 1) Bring snacks; 2) Bring coffee; 3) Bring a camp chair; 4) Bring an extra battery and film cards; and 5) Use a remote trigger.

See you all again in August. I can’t wait to see what Rudy and I will come up with.



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