Saturday, February 09, 2008

Optical color illusion

Optical color illusion. Pretty amazing. Shows us something about relativity.

Friday, February 08, 2008

Teen abstinence study

Teen abstinence study.
Another article.
"The pledging group was also less likely to use condoms during their first sexual experience or get tested for STDs, the study found."

The US militant, sorry, religious right's programs to promote sexual abstinence to teens and deliberately not teach them ways to prevent pregnancy and STDs if they (oh, the shock) turn out to want sex anyway, is deeply braindead. Such a "plan" does not come from a place of compassion, but a place of deep and ingrown emotional constipation. It is coming from the kind of person whose solution to insubordinate children is to beat them severely. He has never seen this work, but it's the only tool he has, and by gawd he's gonna use it til it breaks.

[By the way, I heard of the study on the TV show Studio 60, which is excellent. Written by Aaron "West Wing" Sorkin.]

YouTube cameras

You can now buy cameras which feature "a YouTube capture mode that shoots movie clips in the site’s recommended format and resolution".
I find this amusing because the whole genesis of YouTube is making a web site which made it unnecessary for people to know anything about video formats, the site takes care of it.

New pics too

Update: Bert talked about removing the red post in this one, so I tried it just for fun. I have to admit it has merit.

Thursday, February 07, 2008

Old saying

There's so much good in the worst of us
and so much bad in the best of us
that it's ill advised any of us
to speak against the rest of us

Inline images error

This is funny.
A tutorial about inserting images in blog posts... and the images on the page do not appear... :)

Bert sed:
Is it only me, or is there a change on the Internet? Download speeds are blazing fast "outside hours", and I mean capping my 5Mbps DSL regularly, which seldom happened before.
On the other hand, popular services don't respond like they used to. Blogger often takes its sweet time to load pages. Blogs have missing elements all over. Support is lagging everywhere. My iGoogle home page is not reliable. Like everybody is swamped. Or is it just Google?
What's happening?

TTL said:
Where are you based? During the last couple of days someone has been cutting undersea cables around the world. Total number of damaged cables is now up to five. Iran has been most affected by this.
Quote from the article:
"It may be rare for several cables to go down in a week, but it can happen. Global Marine Systems, a firm that repairs marine cables, says more than 50 cables were cut or damaged in the Atlantic last year; big oceans are criss-crossed by so many cables that a single break has little impact. What was unusual about the damage in the Suez canal was that it took place at a point where two continents' traffic is borne along only three cables. More are being laid. For the moment, there is only one fair conclusion: the internet is vulnerable, in places, but getting more robust."


I particularly like this one.

Green Fence, etc

From today.

Elliott Erwit photography

Elliott Erwitt photography.

Wednesday, February 06, 2008


Mike Reichman pontificates.

"Things are still silly in the digicam field with shirt pocket cameras now up to about 12MP. This means 2.8 micron pixels (or maybe even less) which if this trend continues will begin to impinge on the size of the upper wave lengths of light. Stuffing photons into these little holes is going to start challenging the laws of physics pretty soon.

In the DSLR world sanity seems to be settling in, with pixel counts in the 12 – 14 MP range becoming the norm. The high end of the pro DSLR market seems to be at the 21 – 24 MP range, and while that leaves room for the lower end of the market to still move upward, the ceiling isn't going to get much higher once pixel count gets above 25MP and photosite sizes below 5 microns, because noise will become too big an issue at anything other than moderate level ISOs. Photographers now want image quality above pixel count, or at least I do.

It also needs to be asked – which photographers need these large files? Typical commercial uses (magazines, newspapers, etc) are easily satisfied with files in the low to mid teens, and while a larger file, such as from a Canon 1Ds MKIII, is great for making a 24X36" print, how many people actually need this? Of course a larger files means a greater ability to crop and still get a usable image size, but this then starts to stress lens performance; a bit of a vicious cycle.

So, as far as I'm concerned, anything north of a high quality 12 Megapixels is fine for most applications, and 20+ MP files (whether from a DSLR or a medium format back) are only needed in the work that I do for my most critical landscape work and some commercial projects. (For example, I have a commission to document a major urban renewal project, and in addition to an eventual coffee table book have been told that wall-sized blow-ups for a presentation center will be needed. So, I'll be shooting much of that with a 39MP medium format back.)"

I agree. I would even say that for most users, anything at or over 6 megapixels is quite sufficient. Really. I have big (30cm x 40cm) framed prints on my wall taken with 6-MP cameras, and they look great.

For critical work and most professional work, 10-14 MP is quite sufficient. Anything bigger is only needed for very specialized work, even for pros.

The move to 12-MP pocket cameras is dumb. Fuji totally trashed their previously wonderful low-light capability when they moved up to 12 MP with the F50. (Though I have to say that Canon managed it better with the Ixus 960/SD950.)

Update: here's a site advocating 6MP compact cameras.
... Of course the noise argument hinges on the shaky assumption that light-gathering and processing is standing still. That's not so. Until a couple of years ago, no pocket camera had decent quality above 200 ISO. Then the Fuji F10 came along and showed low noise even at 800 ISO. So I don't think we can assume anything definite about anything.
Also the same amount of noise per 100 pixels will matter less on a camera with more pixels, because the picture has to be enlarged less when printed.

Tuesday, February 05, 2008

Epson 11880

Need a bigger printer to handle the pictures from your new Hasselblad? This one comes recommended, but is probably overkill if your camera can fit in your pocket.

More detailed article. This article says that there are also less gargantuan printers coming with these new technologies, including anti-clogging measures, something which has been needed in the otherwise excellent Epson printers.


This is one of those photos which prove that photography can be a real creative outlet.
Photo by Frank Somma.

How an airplane flies

Pascal just posted this in comments to a post which is not even on the main page anymore! I think the guy is even more compulsive than I am, but you may as well profit.
It's about how an airplane wing forms the pressure difference which gives it lift.
[More here.]

"How this pressure differential is formed is quite frankly a very complex topic"

Not really, honestly. It's related to the physics of fluids flow, and even though the equations (Bernouilli theorem) are a little complicated (high school level), the principle is very simple: "the faster a fluid moves in a circuit, the lower the pressure". When a given circuit has varying sections, in the narrowest ones the linear speed of the fluid increases, and hence its pressure drops. Just take my word for it and the rest becomes very simple.

Air is the fluid that is in relative motion to the plane. Actually it is the plane that's moving, but it makes no difference in the local interactions. The wing profile, in birds as well as airplanes, is more convex on the top side, meaning that the air sliding OVER it has a longer way to travel from the front of the wing to the back in the same amount of time, compared to the air passing UNDER the wing, on the flatter side. A curve between two points is longer than a straight line.
As a result, the air right above the wing travels faster, its pressure decreases relatively to that under the wing, and that difference in pressure is the force which pushes the plane upward and durably lifts it in the air.
The other specificities of the typical wing profile are just for minimizing parasitic turbulences, which would disrupt the regularity of that pressure ratio.

When a plane drops inside a turbulence zone, it's because sudden winds from behind decrease the relative speed of the air flow against the wings. It's just as if the air flow was trying to catch up with the plane. This decreases the pressure differencial, and the airplane drops. If it is too close to the ground, or doesn't reach a zone where this reverse wind ends, sometimes the plane may crash, and you hear about it in the TV news. Or, more often, "airports were closed for safety reasons due to strong winds". Strong enough to compromise the sustentation of the heavier-than-air craft.

One main problem with this pressure difference, is the wing tip. The one place where the two areas of different pressure come in free contact, causing the air to escape laterally toward the top side. Because the wing tip is moving, that imbalance of the system is maintained, and the turbulences are constantly left behind the plane. Their vortex shape is a universal physical curve in nature, you'll find it in the shape of galaxies and solar flares as well as in the microscopic motions of molecules. This tells us that the Universe is fractal in shape.

Every time you notice a wing tip with an odd shape, it's probably a system designed to decrease this loss in sustentation, which can significantly increase fuel consumption. A small, double vertical wing, for instance, becomes an obstacle to top and bottom air simply meeting. In many military jet planes, the delta-shaped wings reduce the actual tip to little more than a point. Eagles, vultures and other ace glider birds have those separated feathers at the end of their wings, resembling fingers: these result in the tip becoming like a group of much smaller wings, aerodynamically speaking, and it not only divides the "parasitic vortex" phenomenon, it also greatly decreases its global scale. Making the glider bird that much more efficient at saving energy in flight. It helps owls be near-totally silent in their night hunts, not even a faint "woosh" to warn the rodents.

Bert replied:

When I wrote that this was a very complex topic, I really meant it!

Although Pascal's explanation is seldom true (not enough lift is created in that manner for most aircraft to fly), I do give him a "A" for effort. :-)

Entire books have been written on this topic, and I can't even remember enough of the mathematics of fluid dynamics to read those. One (and maybe the most important) reason for all this complexity being that not all wings operate on the same principles. Never compare a fighter wing to an airliner wing, and much less to a glider wing. They are all different in form, function and operation.

Beware of too much knowledge. :)

Paper catalogs fighting for life

Paper catalogs fighting for life.

Tilting screen

I'm interested in the new Sony cameras with improved Live View and a tiltable screen.

I'm a fan of those features because to limit your camera viewpoint to eye hight is just silly, and a tiltable screen makes other options far easier.

For example, I could not have taken these humorous pictures of street signs here in town (it's not temporary or a mistake, every single sign is supposed to be there, while the bridge is closed) without the tiltable screen on my old Nikon 2400 (which they sadly have not updated), because to get the perspective I had to hold the camera far above my head.

By the way, which one do you think is best?

Sigma lens

A 16-kilo telezoom lens. Don't try to use it hand-held.

Monday, February 04, 2008

Abba hits collections

Abba is my favorite band after Ministry, Skinny Puppy, Neo Punk Death Metal, and Kill The Baby. So I was looking for a couple of my old favorites from my early records from the seventies. But I found most of the early Abba is not available on iTunes. Except in hits collections. Fortunately there were a bounty of those:

ABBA: Greatest Hits
ABBA: the Definite Collection
ABBA: Gold
ABBA: Number Ones
ABBA: Thank you for the music (box set)
ABBA: Classic Abba
ABBA: 18 hits

I'm not kidding. D'ya think somebody is trying to milk it? :-)

... Anyway, I was sort of kidding about the "favorite band" part, they were slightly too poppy for me, though I liked when I was a kid and I still respect them. But you have to admit: after Lennon/McCartney, Andersson/Ulvaeus was one of the greatest hit-machine teams in pop/rock ever. My gawd, there's barely one song in their numerous albums which does not just slide right in under your skin and stick to your brain, it's amazing. Talk about making it look easy. Think about the number of hard working bands and composers all over the world who would kill to write just a single hit as big as any one of Abba's thirty most popular songs, but it can't seem to happen. Talent is a mystery.

It's funny, I find that the songs I still like the most were those I really love when I was probably not even a teen yet. Like Honey Honey, So Long, and Ring, Ring. I am guessing it is not so much that they are better, but just that my youthful joy is still triggered when they are played now, over thirty years later. It's interesting that you just can't shake that early evaluation of something, and most of the time the bias is not even visible to you.

Sunday, February 03, 2008

Tony Blair investigated for war crimes

"We have killed at least 30,000 and possibly 300,000 children. [...] not one of these people have harmed or attacked Britain."

Video of press conference announcing a Scotland Yard investigation of Tony Blair breaking international war laws.

Personally I find it pretty interesting that you need to have a law telling people that invading other countries and killing innocent people is a bad idea.

Quality digital cameras

The long-expected High-Quality-Compact-digicam Sigma DP1 is finally coming, in spring.

UPDATE: Thanks for Bert for pointing to these sample pictures. I have to admit, they do look really excellent.

It will be interesting to see how it fares. If it really makes significantly better pictures than pocket cameras, and if so, are the compromises worth it? For instance, it has a fixed-focal length lens, and a modest largest aperture of 4.0. Compare with a classic high-quality compact (film) camera, the Konica Hexar, which had the very strong feature of a lens as sharp as any Leica lens, and the high speed of 2.0. All that in a compact camera with autofocus and built-in winder, which cost less than the Leica lens cost alone.

Also, I am made less than optimistic by previous attempts in the genre, to wit the Leica M8 and the Ricoh GR Digital. The former costs $5,000, but in many respects compares poorly to entry level DSLR cameras costing $500. The latter I bought for twice what I paid for the Fujifilm F10, but it did not have a better image quality, and unlike the Fuji it does not even have a zoom lens. It's all quite weird.

Color collections

Sony buzzwords

Nicely tongue-in-cheek article covering a Sony camera press conference.

"09:30: There's a lady on stage now who appears to be talking about cameras but there are so many buzzwords ('leveraging user experience') that I'm not sure."