Monday, February 2, 2015

Exposure

If you want to take photos in anything other than auto/preset modes, you have to understand how to set an exposure. Otherwise you're stuck asking people about 'settings' all the time - which seems to be the approach a lot of people actually take. Stop doing that because you're making this way harder than you need to. If you just ask for settings and I say 'ISO 200, f/8, 1/1000' that doesn't mean anything to you other than 'derp I'll just twist knobs until I get those numbers to show up on my camera'. You need to understand what those things do, then it's really easy to figure out the 'right settings' for any random photo you want to take.

Your camera has three knobs, and turning any of those knobs up will make the photo brighter while turning them down will make the photo dimmer. The difference is knob one decreases the in-focus area while it makes the image brighter, knob two makes moving things blur or streak while it makes the image brighter, and knob three makes more noise and less dynamic range while making the image brighter.

Knob one is your aperture, knob two is your shutter speed, and knob three is the ISO. Depending on your camera they might literally be knobs or they might be menu selections, but they always do the same thing.

So here you are, you want to take a photo but you don't know what the settings should be. Assuming this isn't a film camera, just take a photo with any random settings and see what you get. Too dark? Turn one of the knobs up. Still dark? Turn it (or a different knob) up more. Keep doing this until you produce a well exposed image. Image too light? Turn a knob down instead.

A shortcut is to take the first photo in some kind of auto or semi-auto mode then copy the settings into manual mode, this will put you 'in the ballpark'. I like aperture mode for this.

Now that you have a well exposed image, what are the settings? The real question is why should you care? They're just numbers on the screen.

But how do you know which of the three knobs to turn? That just depends on whether you'd rather change the in-focus area, change the amount of blurring on moving objects, or change the amount of noise. As an example, for a typical daytime landscape I probably want a lot of depth-of-field so I want to leave the aperture around f/8 or f/11. I want low noise (and lots of dynamic range) so I want the ISO around ISO 100. But mountains don't move around much so I can flip the shutter speed all over the place without really worrying about getting blur from moving objects.

That's the whole process - you know what side effect each of the three knobs will have on your photo, decide which side effect is the least important, and just flip that knob until the image looks good.

Saturday, November 22, 2014

Svalbard / C-REX part 1

Sunset over the Arctic Ocean

Well hello folks. I'm writing from Longyearbyen, Svalbard:

I am in a neat place

The sign out the front door of the airport is interesting - 'You're a long way from everywhere, and try not to get eaten by a polar bear':

Signs

Longyearbyen is one of the northernmost settlements in the world, at about 78 degrees north on a remote, rocky island in the Arctic Ocean north of Norway and east of Greenland. Go ahead, look it up; it's pretty far up there. Here's a GPS track of my travel to get here:

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The Sun hasn't risen since I got here, and won't for another couple of months, but the place is quite pretty regardless:

Downtown Longyearbyen

Svalbard

I'm here for a rocket campaign we're calling C-REX, which stands for Cusp Region EXperiment. That site has more info, but the short version is we're studying a density anomaly that occurs in the Earth's magnetic cusp (a region of the magnetosphere, near the north and south poles, open to the solar wind). We will launch a 21 meter rocket to around 600km altitude (higher than the space station!) and it will release 24 sub-payloads on the way back down. These sub-payloads are artificial chemical-clouds that will glow in the twilit sky, some of them drifting with the high altitude wind and some convecting with the magnetic field. This summer I went to North Carolina or a test launch of this system and, though that first test was unsuccessful, we did have a mostly successful launch on the second attempt. I now realize I never wrote that up here, so here is a picture and a video of the test release:

Rocket release



There are more polar bears (isbjørn - 'ice-bear') than people on Svalbard, and to quote a recent Facebook status of mine: "The polar bear is not only the largest land predator on Earth (and unequaled in sheer physical power), it's also the only one that will attack humans as a regular matter of finding food, rather than only attacking humans when it's sick or weak or starving or defensive. They can go 8 months without eating, and can smell a seal buried under 3 feet of snow from a mile away. It spends its whole life alone, only tolerating other bears for mating and brief interactions, and is constantly on the move, walking a few thousand miles per year. It is also an excellent swimmer, with one radio collared bear having swam continuously for 9 days through the Bering Sea to reach ice 400 miles from land, where she then immediately walked another 1,100 miles." They're amazing animals but require caution and respect, so UNIS (University Center in Svalbard) provides a training class that includes polar bear behavior and practice with flare guns and rifles. Here's me firing a flashbang out of the flare gun. Yes, we're trained to look away from the signal gun when we fire it, due to 1. It's not that accurate of a weapon to begin with, and 2. The possibility of blowback into your eyes:

Me firing a flare gun

Flashbang

I also took a couple of visits up to the KHO Observatory to help install cameras there. To get to KHO we drive up to Mine 7, a few miles from town, then since the road isn't maintained in winter we switch to this awesome tracked snow wagon to climb the last mile or so to the observatory:

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We pass the Svalbard EISCAT site during the snow wagon ride:

Dishes

And the other morning we took our first shakedown flight in the NASA aircraft, everything seems to be ready to go. I took this shot of some aurora to the south towards the almost-but-not-quite-sunrise:

This morning over the Arctic Ocean

So here I am. Our first opportunity for launch comes Monday morning, my role is to fly in a NASA aircraft and photo/film the releases from the air just south of Svalbard; we also have observers running cameras at Kjell Henriksen Observatory on top of a mountain just outside Longyearbyen (central-west Svalbard) and at the Japanese Rabben Observatory in Ny-Ålesund (northwest Svalbard). I gave the local photo club a brief presentation on what to expect so hopefully some of them will be able to get some great photos of what should be a beautiful event; 24 of those glowing clouds over the epic Svalbard landscape. I know I'll have several cameras set up to hopefully get something, though that requires planning since I myself will be on the airplane at the time of launch. Here's hoping for the best.

Friday, October 10, 2014

Pluto is or isn't a planet

This happened recently. Short version, some people are still upset about the 2009 redefinition of Pluto to 'not a planet'. Quoting from the article: "The decision did not sit well with the public. Some amateur stargazers and some astronomers thought it rather arbitrary." So they held some kind of vote and the audience voted to 'reinstate' Pluto as a planet.

You remember when the whole 'Pluto isn't a planet' thing happened right? It was all over the media, and people were up in arms on social media. You'd think it was BIG SCIENCE NEWS based on all that. I got asked recently, as I did several times back then, what was my position on it since I'm an 'astronomy person'. My position is I don't care. This isn't BIG SCIENCE NEWS, it's semantics. Nothing new was discovered, no new theory was proposed. Whether you call Pluto a planet or not changes nothing about what it is. It's trivial.

Here's the thing, I don't think this is a one-off misunderstanding about Pluto. I think this is a symptom of a deeper problem that a lot of people don't understand a fundamental aspect of science. Here's an illustration of the 'Pluto problem':


The 'problem' here has nothing to do with Pluto, it's taking the black-and-white taxonomic categories too literally. The universe (at least on the macroscopic scale) is a continuum, but we like to classify things into boxes. This or that, is or is not. But the real world just isn't like that. Where do you draw the line separating the 'planet' box from the 'not a planet' box? You can draw it anywhere, and no matter where you put it the things on one side of the line aren't going to be very different from the things on the other side of the line. You try to put the line in the most useful place possible but it's still arbitrary by it's very nature. This is a 'problem' of applying binary logic to a continuum.

I'm not sure if this system of categorizing things into boxes is useful in itself or it's only useful because our brains want to work that way, but either way it's useful. The concept of a species is extremely useful in biology even if, when you look close, you realize the concept doesn't apply very well to the reality. Taking the concept for reality is probably a big factor in popular misunderstandings and misrepresentations of evolution - it's pretty easy to take the concept and say something silly like 'one species can't give birth to another', and that makes sense if you think 'species' represents a real division in nature.

I'm not saying to forget the boxes, the boxes are still a useful way of thinking. But at the end of the day you have to remember we invented the boxes. We decide what goes in what box, and putting something in one box rather than another doesn't change anything about the way things are. It's a mental tool to help you understand how things relate to one another; the boxes aren't a real part of nature.

"Some amateur stargazers and some astronomers thought it rather arbitrary." Well duh.

As an aside, I should mention something about how thousands of science enthusiasts got up in arms to defend the way they were taught rather than being willing to change their mental model to best fit the world. This is the same attitude they'll decry in their anti-science bogeymen.

Tuesday, September 23, 2014

Nabesna Ghost Town

Camping in a ghost town

This weekend I planned to take a kayak trip down the Delta River, from Tangle Lakes to just below Phelan Creek and Rainbow Ridge. But the weather forecast was bad, so at the last minute (inspired by this blog post popping up in my news feed) the plan was changed to visit the old mining town of Nabesna. Nabesna is at the end of Nabesna Road in Wrangell-St. Elias National Park, America's largest national park (larger than Vermont and New Hampshire combined), which contains only two roads: The McCarthy Road to Kennicott, where all the visitors go, and the Nabesna Road, where almost no one goes. I've been to the end of the Nabesna Road before, and walked up to the Rambler Mine, but I didn't know there was another mine and ghost town just another mile down the path.

I couldn't find much info about Nabesna online, other than it's about 2 miles past the official end of the road, so I decided to just go for it. Worst case scenario I spend a day hiking off the Nabesna Road, which isn't so bad. Drew and I left Fairbanks about 8:00pm Friday, camped out next to the Chistochina River just east of Gakona, and got up early to hit the Nabesna Road around 8:00am. We stopped at the ranger station at the beginning of the road in Slana, where we got a free CD of an audio tour to play along the road. The narration was interesting, it was worth the stop. The ranger asked where we heading and I said we wanted to try to get all the way to Nabesna. She told me what I already knew, that the road ends about 2 miles short of the town. I asked if there was any possibility of driving the final 2 miles and she said no, 'ankle express' only. I didn't press on whether she was just saying that because she didn't think we'd make it. With that, we headed down the road.

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For the first half of the road, there's national park on the right side and national preserve on the left side. The main difference is that only local subsistence hunters can hunt in the park. We saw many spruce grouse on the road, and we intended to make a dinner out of a few but could only go after grouse on the left side of the road. We did get 4 grouse, and decided that was enough so just passed by the rest.



By the way, do you know the fast way to clean a spruce grouse? The Alaska Fish and Game website mentions it as an aside, with the advice that it's 'probably better demonstrated than described'. So, here's a video where I demonstrate it. This is absurd enough that I think it's more interesting than anything, but this is a video of me literally ripping a grouse in half. You've been warned:



We parked at the end of the road and decided to hike the last bit to Nabesna. ~1.5 miles further on we came to a fork in the road, with a very overgrown path ahead and an opening to smelly tailings mud on the right. We took the right fork and were at what I assume was the Nabesna processing plant (the actual mine was visible much further up the mountain).

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We had left the bulk of our water supply in the car, hoping to find a stream to filter from, but none were apparent. More importantly, we realized we left the beer in the car. After walking the road in I was pretty sure my car could make it, so we left our packs, walked the short distance back to the car, and drove the car all the way in to Nabesna. No big difficulty, just an exercise in dodging ruts. A car with less ground clearance might have trouble as the entrance/exit angles ot some of the mudholes was steeper than it looks in this video. I parked at the garage next to an old yellow truck:



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We walked on into town and started looking into the various cabins. Apparently this town once housed around 200 people. We found 4 rows of cabins, with possibly more hidden in the brush, and the two middle rows had boardwalks down them:

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Near the center were two larger cabins which, judging by the contents, were the lab/workshop and the office/kitchen. We settled upon the office as the most welcoming, and cached our gear inside.

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Time to explore!

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Item number one in the 'do not touch' list. Potassium Nitrate is a strong oxidizer, and being sealed for so long, crystals may form under the lid that get crushed/scraped when opened. I'm not sure how dangerous that is without a flame nearby, but now isn't the time to find out:

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Item number two for 'Do not touch'. Not sure if this is just a box or if there's actually anything dangerous in it. Old dynamite sweats nitroglycerine, which is a contact explosive:

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Lab notes, unmarked chemicals. We'll not touch that one too just to be safe:

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1939 mining journals. I think the mine was most active in the 30's-50's, though there was a good bit of clutter from the 80's and a couple of more recent pieces:

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We then walked over to the processing plant for more exploring:

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There was a chute coming from the (dry) stream uphill, leading to this big turbine:

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Then flywheels set in the ceiling above it:

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It looks like they tapped the stream for water power, turning the turbine for electricity and the flywheels to power some machinery directly.

The view from the plant of the mountains and river was spectacular:

Nabesna AK

By this point it was getting late, time to cook dinner. Drew found a splitting maul and an axe so we cut some wood, cleaned the grouse breasts, and built a smoker out of some scavenged metal grate, aluminum foil from the kitchen, a beat up washtub and some planks to seal it. We ate 2.5 birds for dinner and used the rest to make toasted grouse and pepperjack sandwiches for lunch the next day.

From looking like some horrific thing from your nightmares to tasty sandwiches:

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The Sun was starting to go down, and we expected it to get chilly at night so we cleared an area in the middle of the office floor to set up our tents, as seen in the first picture here. And we were never heard from again...

Well I can at least say it was VERY dark in my tent, in a building, under an overcast sky. But it was quiet and calm and warm(ish). I was woken up by some unidentified small animal scampering through the piles of old maps right next to my tent. We packed up and headed back to Fairbanks, with a last view of ~16,000 fot Mt Sanford on the way out:

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BONUS ADVENTURE

Near Isabel Pass there's a road that looks like it goes up towards a glacier. We decided to see how far it goes. The answer is 2 miles or so, as the road gradually turns into a creek. Here's 4 minutes of video from driving back out, so the creek turns more roadlike the further you go.



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Also, this:

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