By GI Korea on June 24th, 2011 at 1:00 pm

Picture of the Day: Han River Boarding

» by GI Korea in: Picture of the Day

A wakeboard athlete is showing off skills on the Han River in Seoul Tuesday as temperatures top 30 degrees Celsius.

Via KBS Global.

Tags: Han River, Seoul

- 215 views

Teadrinker
3:42 pm on June 24th, 2011 1
Right, we get it. The Han River is the cleanest river in the world, literally and figuratively so.
kushibo
3:58 pm on June 24th, 2011 2
It most certainly is not. Have I not mentinoned the gasoline taste when you windsurf near the jet skis?!

But it is nice to have the Han River there for so much water and near-water activities. I grew up near the ocean, and if it weren’t for the huge river transversing the city, I don’t know if I’d enjoy living there. I’d have to head for Pusan or Sŏgwipo or something.

Some day I’ll make a movie about my experiences along the Han. It will be called A River Runs Through It(aewon)™.
Teadrinker
5:02 pm on June 24th, 2011 3
The picture is shit, by the way. The grey water and sky totally ruins it. You can’t change Seoul, but a filter on the camera would have helped.
ChickenHead
9:02 pm on June 24th, 2011 4
The only filters that would help that picture are air and water filters.

Anything on the camera that improves the air and water color will make the guy look green.

But what old man uses lens filters instead of this-here newfangled Photoshop thingie?
Teadrinker
10:38 pm on June 24th, 2011 5
Not quite. A neutral density filter would have worked. But, yes, Photoshop would have been another option. Frankly, if the idea was to get people excited about the Han River (and convince them that LMB’s plan to clean it up worked), then that picture fails.
ChickenHead
12:20 am on June 25th, 2011 6
“A neutral density filter would have worked.”

Hmmm… tell me more.

In my understanding/experience, a neutral density filter simply reduces the light that reaches the film. By design (the “neutral” part) it cuts all wavelengths equally… having no effect on hue… and no ability to bring out the blue color on its own.

The sky is lacking blue due to haze and over-exposure but, for sharpness and depth of field, a faster shutter speed and smaller aperture are greatly preferable to a filter in an action shot such as this.

Therefore, a neutral density filter would be a poor choice that would not bring out the blue yet would increase blur and decrease depth of field/safety margin for focal sloppiness.

This same picture could have been taken well without filters simply by reducing over-exposure.

Without filters, I would point the camera at the sky and lock the exposure settings… adjusting the aperture rather than the shutter speed to reduce motion blur with the trade-off being depth of field which is not a big deal here. This would give me a nice blue sky and probably a much bluer water.

I would shoot with a flash (making sure my fastest-possible shutter speed didn’t exceed the synch speed). This would brighten the guy back to normal and reduce his unsightly shadows.

Or, like I do these days, I’d take the picture with my phone and touch it up in Photoshop.

I made an entire tiny little lens set for the camera on my phone.

80mm glasses lens blanks are 7,000 won each and are available from (in non-technical terms) very magnifying to very wide angle. I cut a tiny lens from the center and machine a plastic housing that attaches over the lens on my phone.

For wide angle, I use a -12 diopter lens. As it is not a triplet, this gives some chromatic distortion around the edges but, at 5 megapixels, I can crop it… although it is not noticeable without zooming in.

For macro, a +12 diopter works just fine. A doublet would work better… but, since one lens by itself worked fine in the first test, why fix what isn’t broken.

For zoom, I cheated and use one of those tiny little pocket telescopes you can buy in the market for ten thousand won. I had to insert a + diopter lens between the phone and telescope to compensate for the lens already in the phone otherwise the image was circularly cropped. Telescopes and binoculars with a wide field of view don’t require any lens for your camera phone (or digital camera) to take great pictures through them. Try it.

Another great trick is to remove the IR filter from your old digital camera… then put in an IR pass filter. I make them from blue and red lighting gels which pass all the IR yet block almost all the visible light. You have an instant IR camera.

With all the IR light leaking out of everything, you can take photos in the dark in a lot of places. This is changing with more LED and compact fluorescent lighting. Some material is transparent to IR so, yes, sometimes, you can get a murky picture of a girl’s bra through a translucent shirt. You can quickly identify every video camera with IR lighting that you normally cannot see… including hidden/discrete ones that you didn’t know existed.

I give a guest lecture in an optics class every semester with some of my exceedingly cool optics experiments.

I LOVE to geek out and I have the tools to do it in a big way… but one big sadness in my current life is that…

1) Korean students have no idea… and, mostly, no real desire to play with this kind of stuff.

2) Korean engineers have no interest in doing as a hobby what they have to do at work all day (as most of them had their major chosen for them)… see #1.

3) English teachers all have degrees in The History of Comparative Lesbian Underwater Basket Weaving and have no desire or ability to geek out.

4) ALL of the foreigners I met who have claimed to be working in Korea as scientists or engineers were full of shyt and were simply private English teachers on tourist visas thinking they could bullshyt other foreigners who mostly had degrees in The History of Comparative Lesbian Underwater Basket Weaving or some such.

Oh, well.
Lemmy
1:52 am on June 25th, 2011 7
The title should read: “Wake-Boarder Sets New Record and Jumps 12 Spent Condoms, 19 Tampon Applicators, and 37 Turds”
kangaji
4:52 am on June 25th, 2011 8
Comparative Lesbian Underwater Basket Weaving combined with an Engineering Degree could result in an improved HESCO barrier…
Teadrinker
10:00 pm on June 25th, 2011 9
“Hmmm… tell me more.

In my understanding/experience, a neutral density filter simply reduces the light that reaches the film.”

That’s the idea. Sure, it won’t bring out the blue, but the image won’t be as white. Yes, reducing over-exposure would probably be a better idea. The point I was making is that even I, who’s really not interested in photography, can see the flaws in that picture.

“3) English teachers all have degrees in The History of Comparative Lesbian Underwater Basket Weaving and have no desire or ability to geek out.

4) ALL of the foreigners I met who have claimed to be working in Korea as scientists or engineers were full of shyt and were simply private English teachers on tourist visas thinking they could bullshyt other foreigners who mostly had degrees in The History of Comparative Lesbian Underwater Basket Weaving or some such.”

Hey, my degree in science is real. I love science, but never really intended on making a career out of it.

I won’t argue that you’re the biggest geek here, but you’re not the only one. I’ve got a soldering gun and box full of resistors, capacitors, and potentiometers too (my last project was rewiring my Les Paul with 4 push-pull pots in order to get 22 different pickup variations out of it instead of the stock three).
Teadrinker
10:15 pm on June 25th, 2011 10
PS. I had a student many years ago, an engineering student, that you would have loved. We went to Yongsan together once. I was looking for computer parts, and he was looking for a part he needed to transform an old CD-ROM he had into a car CD player.
Teadrinker
10:22 pm on June 25th, 2011 11
“Another great trick is to remove the IR filter from your old digital camera… then put in an IR pass filter. I make them from blue and red lighting gels which pass all the IR yet block almost all the visible light. You have an instant IR camera.

With all the IR light leaking out of everything, you can take photos in the dark in a lot of places. This is changing with more LED and compact fluorescent lighting. Some material is transparent to IR so, yes, sometimes, you can get a murky picture of a girl’s bra through a translucent shirt. You can quickly identify every video camera with IR lighting that you normally cannot see… including hidden/discrete ones that you didn’t know existed.”

This is very interesting (and not for the girl’s bra part). We travel a lot and I always wonder if some pervert hid a camera in the hotel rooms we stay at. Besides, an IR camera…That’s just plain cool.
ChickenHead
1:39 am on June 26th, 2011 12
Teadrinker,

Your cellphone camera, having a CCD sensor, is very sensitive to near IR.

There is an IR filter behind the lens but even with this filter, there is some sensitivity to IR.

For this reason, you can use your cellphone camera to look for hidden IR sources.

To test this out, get your TV remote control, press a button and look at it with your cellphone camera. You should clearly see the IR LED blinking. It will probably be purple.

Next, test it on known cameras at apartment complexes and such to get an idea what you are looking for.

Remember, you cannot find hidden cameras that don’t have IR lighting.

On an interesting note, despite the lies of science teachers, humans can see IR just fine. It isn’t like there is a sudden drop-off in IR sensitivity. There is a gradual decrease from a sensitivity peak in green down through IR. The reason we don’t notice this is because we are so much more sensitive to visible light that we don’t notice the IR.

I took some goggles with a tight seal round the eyes and replaced the lenses with IR pass filters. Then I went outside on a sunny day. At first, everything is black… but then you start to see things… and, within 15 minutes, you can see almost normally.

Everything is shades of grey, pink, and ultra-deep red.

Trees, which reflect IR well, are bright pink. The sky is black. Cars are all close shades of reddish gray.

People stare it the foreigner walking on the street with black spaceman goggles gawking intently at walls and bushes and anthills.
Glans
2:09 am on June 26th, 2011 13
ChickenHead 12, if you can see it, it’s visible! Your ‘IR pass’ filters were also passing small amounts of visible light.
Lemmy
3:23 am on June 26th, 2011 14
Other than a polarizer, why would you need any filter on a DIGITAL camera? Adobe works for everything.
Glans
3:31 am on June 26th, 2011 15
Lemmy 14, that’s a good question. When will we have a camera whose image can be adjusted for polarization after exposure?
ChickenHead
4:05 am on June 26th, 2011 16
Glans,

“ChickenHead 12, if you can see it, it’s visible! Your ‘IR pass’ filters were also passing small amounts of visible light.”

Hahahaha! You probably still think glass is a liquid, reentering spacecraft get hot due to friction, and we have only 5 senses.

Since I have the absorption graphs for the filters, I know exactly what wavelengths are being passed… and the cutoff is around 800nm… lower than what is officially considered the lower range of human vision… as most graphs show zero after 700nm or so… but, in reality sensitivity tapers off asymptotically with a small but nonzero sensitivity up to 900-950nm.

This was further tested with LEDs which have no IR output. Their light was filtered.

Go back to mindless ranting about Global Warming Pop Science and leave the real scientificy stuff to the big boys who Do To Understand rather than just Talk.

http://www.opticsinfobase.org/abstract.cfm?URI=josa-53-6-765

In your favor, though, a quick Google search revealed almost no concrete pop-sci information about this ability… and very few for-pay research papers.

I guess nobody cares about this ability.

Here is an easy way for you to demonstrate this to yourself.

Remote controls use IR LEDs that are all below 800nm and have a very narrow bandwidth. Go to a dark room for a while, look directly into the LED from a few inches away, and push a button. Depending on the quality of your eyes, the IR might be bright enough to stimulate the red cones and you will see the light.

In fact, as a science project, EVERYBODY here should try this and see how many people can see a faint dark red coming from their remote. You can verify the LED works using your cellphone camera, digital camera, webcam, camcorder, etc.

Glans, if you would understand and speak intelligently about it, I would tell you about my electrophosphene amplifier which allows me to “see” electromagnetic fields (such as produced by transformers) with my eyes. It is REALLY wild. Someday, I will build a better one that will let me see whose cellphones are transmitting. How cool would that be?
Teadrinker
4:20 am on June 26th, 2011 17
#13,

Thanks for the pointer. I tried it out with my TV remote. I can clearly see the LED, it appears violet on my phone.

Have you ever tried making an IR filter using unexposed developed film? It apparently works.

“I took some goggles with a tight seal round the eyes and replaced the lenses with IR pass filters. Then I went outside on a sunny day. At first, everything is black… but then you start to see things… and, within 15 minutes, you can see almost normally. ”

I wonder, wouldn’t walking around wearing dark lenses like that make your eyes more sensitive to UV light damage?
Teadrinker
5:04 am on June 26th, 2011 18
“Hahahaha! You probably still think glass is a liquid, reentering spacecraft get hot due to friction, and we have only 5 senses.”

1) Depending on how you look at it, it can be argued that it’s a highly viscous liquid, an amorphous solid, or neither liquid nor solid. But, since glass is solid at room temperature…

2) Nope, it gets hot because it rapidly compresses air. Rapidly compressed air gets hot (conservation of energy).

3) Physical senses? Sight, hearing, smell, taste, pain, heat, cold, pressure, motion, and balance.

The psychological senses are too numerous to list them all (sense of time, common sense, illusion, hallucination, delusion, sense of community, identity, comfort, relief, etc).
Glans
11:15 pm on June 30th, 2011 19
ChickenHead 16, Teadrinker 18, the term ‘friction’ is conventionally applied to a force between solids which turns kinetic energy into heat. In the case of the reentering spacecraft too, kinetic energy gets turned into heat, so it’s not a big sin to call that a kind of friction.

If you can see a wavelength that some book calls ‘infrared’ – by gosh it’s visible! Your brain reads the book (with the help of your cones!) but the cones don’t obey the book.

They’re like carbon dioxide, absorbing infrared without regard to ideology, indifferent to economic considerations, oblivious to Al Gore.
ChickenHead
1:42 am on July 1st, 2011 20
Glans,

Again, leave the science to the scientists.

Friction and gas laws are two completely different mechanisms of transforming mechanical energy into thermal energy.

So, yes, from a scientific standpoint, it IS a big sin to “call that a kind of friction”… since you would be completely against a few hundred years of well-established science.

An analogy you might better understand is…

If you have a physical and the doctor puts a finger in your bottom as part of a standard test… or you go to a gay leather bar dressed as a sissy with a can of Crisco and beg everybody to fist you in a toilet stall, the results are similar but the mechanism is very different… and only one is “not a big sin to call that a kind of” perversion.

Or… maybe… do DON’T know the difference.

I didn’t think of that.

As for your argument that any light you can see is “visible” light, there are a couple of ways to look at it.

Let’s make all stop lights only work in IR from now on. We should be able to compile some statistics on its visibility. I’m guessing the result can be classified as “not visible”.

The reality is this…

1. Not everyone can see those frequencies

2. For those who can, the sensitivity is so low that all higher frequencies must be filtered out for them to be noticed.

3. It is likely that the eye is not actually “seeing” the IR light but the actual mechanism is due to the intensity of the IR being so high that it triggers the red cones.

There are other examples of high-amplitude electromagnetic radiation, unarguably far from the “visible” spectrum, which trigger an optical sensation… although it usually results in the death of the observer.

BTW, it almost sounds like you are building up courage to indirectly yap about global warming again. You have avoided giving any of your misleading and incorrect opinions for a long time… and we appreciate that. Keep up the good work… unless, of course, you want to answer any of the direct questions you were asked.