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Sunday, 27 March 2016

Comments

Mike, Thanks for that link to TED talk. Too bad he did not say photography keeps we people happy and contented. Yes it does.

Easter Prom-

Instructions on how to make a beer can pinhole camera and a "solargraph" one are available on Justin Quinnell's website:

http://www.pinholephotography.org/

Justin runs some great classes. I went to one he was running at the Fox Talbot Museum at Lacock Abbey a couple of years back. He has an inimitable style, as you can see from his youtube videos.

Easter is a time of sweet foil-wrapped chocolate. Not good chocolate but good enough for a six year old.

Mike, unlike you as a kid I never questioned the logic of the easter bunny/ He brought us chocolate eggs. I'm a firm believer in 'never look a gift horse in the mouth'. But I still don't understand how a horse can purchase gifts in the first place.

Easter is also a time for trampling kids:
http://www.dailymail.co.uk/news/article-3511343/Marauding-parents-Easter-Egg-hunt-rampage-control-adults-push-children-ground-steal-buckets-leave-one-four-year-old-bloody-chaotic-free-event.html

Thirty years of family practice in Devon UK would make me agree with Mr Waldinger whole heartedly.
Spending a wonderful Easter in the God's Own County of Yorkshire with my wife Sarah, my two kids and old friends is a joy. Nice to think it may be a good health policy too!
Win win and Easter Eggs as well. Perfect.

I have always thought the rabbit and eggs are both symbols of fertility and included into easter when christianity hijacked these pagan spring rites for their own purposes. The chocolate part I suspect was easter being hijacked in turn by Cadburys.

The video is a timely follow-up to the eight hour work day post. As I commented on that one, I've never been interested in "achieving" as seems to be expected by everyone around us. I have led a contented and privileged life so far, mainly because I didn't follow the expectations. I remember my school reports almost always had a comment by the teachers "could do better" when in fact I was already getting straight A grades. I wasn't going to stress trying to do more than was necessary - unless of course I was passionate about something. I focused on my health and happiness from a very early age and for the past 26 years have also shared those principles with my wife, who happens to be my best friend too.

Thank you for the "Easter egg" of sun tracings. And for the TED talk. Just by happenstance, I next clicked on a link in WSJ online about happiness in retirement and learned the following: a person's "well-being starts out quite high in early adulthood, reaches a nadir in midlife and then increases to a peak in our later years."
At 74, I can look back and see that same curve in my own life.

Mike, I hope you can consider all of us readers and subscribers and commenters part of your own connectedness. And that many many folks sign up for a portfolio review with you. And that as Spring arrives, then turns into Summer, more and more opportunities to get out with your camera generate more opportunities for connection. (You haven't been there for peak vacation season as yet, have you? I'll bet the difference in clientele at TOPS supermarket will be astonishing.)

Thanks Mike for sharing the Ted Talk video, it initiated some great discussion around our dining table across generations.

Thank you, Mike, for the TED talk. The topic is much-discussed, but Dr Waldinger brings the most impressive evidence. It's a great encouragement to tend that relationship garden, which can become pretty sparse as we age. So glad that you feel you have come to life.

"a watched pot never boils."

Often misinterpreted as meaning that time feels longer when you're waiting for something to happen and that anxious waiting does not speed up whatever you are waiting for.

Actually it means more or less the opposite. When cooking, more often than not, a pot boiling is a very bad thing. (kettles are for boiling) If you pay attention to what you are doing i.e. watch the pot, then you can prevent the bad thing from happening. *

In farming "the most important thing a farmer can put on the land is his shadow" is a similar aphorism for pay attention to what you are doing so bad things don't happen.

There are infinite possibilities in the world, many of which you can avoid if you are paying attention.

*when I was China 30 years ago, my guide told me that there was a similar aphorism concerning cooking and burning down one's home, when I asked why traditional Chinese homes had the kitchen in a separate building.

Thanks for that elegant verse. Down-under of course this has not much relevance but for my friends in Quebec, to whom I've sent it as part of a chain poetry email, those words mean a great deal.

Mike - un Italy we have chocolate eggs eggs but no bunnies, and in Spain neither --- it seems that the bunny and egg things are really remnants of the pre-Christian festivity (spring, basically, sometime attributed to Ishtar, goddess of sex and fertility; eggs and rabbits are since forever associated to fertility for obvious reasons....).

It would seem that Madison, Wisconsin, has very sunny winters.

That sunpath pinhole picture taken by a student at the University of Wisconsin-Madison is indeed pretty cool.

Mentally picture a tin can with a Warholesque Campbell paper label wrapped on the outside.

Imagine now that you wrap, inside that tin can, a photosensitive paper.
Then drill a tiny hole on the side of the can, and you've got a nice pinhole camera.

If the photosensitive paper completely wraps the can's inside circumference, then, that pinhole camera will have an almost 180 degrees horizontal field of view — the kind of angle of view that's only feasible with a fisheye lens.

The vertical angle of view, OTOH, will be much more limited, and will depend on the can's diameter to height ratio.

Short tin cans will have a very narrow vertical angle of view.
Conversely, tall tin cans will have a wider vertical angle of view, provided, of course, that the photosensitive paper inside the can is tall enough.

Examining that UWM sunpath picture in Photoshop, a few observations come to mind.

The picture isn't level, as the horizon seems to be slightly tilted (about 1.3 degrees, based on some measurements in Photoshop). This tilt, however, isn't really relevant to the measurements we can make.

According to Google Maps, the UWM's Sterling Hall building is at a latitude of about 43.0744°

The Earth's axial tilt is about 23.44°

This implies that, at the winter solstice, the maximum altitude reached by the sun above UW-Madison is 90°-axialTilt-latitude = 90°-23.44°-43.0744° ~= 23.486°

At the summer solstice, the sun would reach an altitude of 90°-axialTilt+latitude = 90°-23.44°+43.0744° ~= 70.366°

So, to capture a picture of the horizon and the apical sunpath traces between the winter and summer solstices, a camera, if held in the horizontal position, would require a vertical angle of view of at least two times 70.366° — i.e. about 141°

The UWM student's pinhole camera seems to have been pointed slightly upwards, as the horizon hasn't been imaged as a perfectly straight line, but rather as a line with a slight curvature.
We already know that the distance on the picture between the horizon line and the apex of the winter solstice sunpath must correspond to 23.486°
The magnitude of the downward deflection of the horizon curve would then be consistent with a camera being pointed slightly upwards, by about 2.8°

As the vertical distance from the image center is proportional to the tangent of the incoming light ray, we can then calculate that the upper edge of the pinhole picture corresponds to an altitude of about 44.9°

This is much lower than the 70.366° altitde that the sun can reach above UW-Madison, and it's thus not really surprising that the sunpaths are clipped in the vertical direction.

Are the sunpaths also clipped in the horizontal direction ?

Remember that, north of the Arctic Circle, the sun in the summer can be above the horizon even at midnight.
As the sun doesn't set, then, a complete capture of the sunpath during a 24-hour summer day would require an angle of view of 360°, which is obviously a horizontal angle of view beyond the widest of the fisheyes, and require a very special camera.

UW-Madison is at a far more southern latitude than the Arctic Circle. Astronomical charts indicate that, at a latitude of 43.0744° the sun would travel an angle of about 247° between sunrise and sunset on the summer solstice.

As a pinhole camera can have a horizontal angle of view of at most 180°, it would be impossible not to clip the sunpath between sunrise and sunset at the summer solstice.

In fact, at the summer solstice, even at the equator, the sunrays at sunrise would arrive at an angle equal to the Earth's axial tilt — i.e. 23.44° - relative to the East-West line, and the sunset lightray would also be at an angle of 23.44° relative to the E-W line. Thus, the total horizontal angle between sunset and sunrise would be 180°+23.44°+23.44° ~= 227° at the equator, which, while less wide than the 360° horizontal angle of view required at the Arctic Circle, would still be slightly wider what this fisheye can achieve...

It's hopefully so obvious that I forgot to add it to my comment above, but if a camera lens — e.g. a 50mm F/1.4 — is used to project an image of the sun on a piece of paper on a sunny day, said lens can easily burn that piece of paper.

Thus, NEVER point a camera with a fast photographic lens towards the sun, unless you want to burn holes on your shutter or your imaging sensor.

The sun is dangerous, and sunpath photography is an activity that's best left to pinhole cameras...

Bunnies, chocolate eggs, Jesus. It's all mythology.

Thanks for the TED talk. It's a good thing to keep in mind when things get difficult, as they do sometimes.

There is a guy in that video that looks just like you....

I showed my third (current, final) wife that video and she rolled her eyes.

In a book suffused with wisdom, I've always enjoyed this passage from Bryan Magee's Confessions of a Philosopher:

The world is governed by false values. People in all societies seem anxious to do what they think is the done thing, and are terrified of social disapproval.They set their hearts on getting on in the world, being thought highly of by their fellows, being powerful, acquiring money and possessions, knowing "important" people. They admire the influential, the rich, the famous, the well-born, the holders of rank and position. But none of these things have any serious relationship to merit: as often as not they are ill gotten, and nearly always they are partly dependent on chance. None of them will protect a person from serious illness or personal tragedy, let lone from death. And none of them can be taken out of this world. They are not an inherent part of the person himself but are merely external decorations, hung on him. They are the tinsel of life, glittering but worthless. The things that really matter in human beings are the things that can matter more than life itself: loving and being loved, devotion to truth, integrity, courage, compassion, and other qualities along entirely different lines. But human beings are all the time sacrificing these true values to the false ones: they compromise themselves to get on, bend the truth to make money, demean themselves before power. In behaving like this they are pouring rubbish over their own heads. If they stopped abasing themselves in this way and started living in accordance with true values their lives would become incomparably more meaningful, more genuinely satisfying. They would even, to put it at its most superficial, be happier.

Thanks Mike, I needed this too.

Eolake, living alone, mailing on my friggin phone, late at night in a Manchester cardiac unit.

I'm ok though. Had a procedure, and I think will be a turnaround point for me.

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