Wednesday, October 24, 2007

In the Throat


I have been deliberately slow to post any remarks about the fires we’re having around here this week. I’m fine. The fires are nowhere near me, but they’re all around me, from south to east to north. Their effect on the sky over me is hard to ignore.

But I’m not among the fires; I’m just surrounded by them. The nearest is probably fifty miles away. Except for what I see in the newspapers, I probably notice the effect of only one or two of the many fires all over the Southland. The rest are too far to touch my surroundings at all.

Thousands of people have lost their homes; hundreds of thousands—more than the total population of Long Beach or San Francisco—have had to leave their homes behind while fire crews fight the inferno. The net effect in my life has been to wipe up a tiny layer of ash from my kitchen drainboard.

But a couple of people by now have asked, just checking in to make sure I’m still breathing, I suppose. Yes, there has been a tiny whiff of wood smoke on the air lately. And the sunsets have been rich with color, if too hazy to burst with dramatic shapes.

“True” and “color” are a restless match. Our eyes are marvels, constantly adjusting to catch up with current lighting conditions, trying to represent the world around us in a way our brains can use. To us, a red beach ball looks about the same at night, by day, or under fluorescent lights. Sure, it’s not identical, but we recognize it each time. Cameras generally wallow along hopelessly behind our sophisticated system of visual perception. They usually start by trying to represent what a scene actually looked like.

Take a scene from a beach, a picture taken last Sunday. This is what the camera “saw”:

That’s already a little deceptive, because it’s actually how the camera interpreted the light that came through the lens, based on various settings I have adjusted. I let the camera decide how bright to make the picture overall, but I’ve got it set to skew the colors so they’ll be a tiny bit richer, and a little warmer. So it ingests the light, and then it applies a couple of adjustments before it ever records the scene. Then I get home and apply my fine tuning. Anyhow, what’s above is what came out of the camera, unadjusted.

“White balance” refers to an attempt to make sure that the various primary colors in a picture are equally well represented, ranging from absolute black to absolute white. It’s a dodgy business on a good day, but computers are getting better at guessing what’s right. Above is the same beach scene, using Photoshop’s automatic white balance adjustment. This actually overexaggerated the contrast from what I originally saw (trying to get an absolute black), and it made the shadows more blue than what I remembered.

This is the picture as I posted it on this blog on Sunday. I tried to preserve the relative balance of the tints (not skewing the shadows heavily toward blue), but I did enrich the colors a little, by both brightening the light spots and darkening the shadows. What did I really see, and what did the sand really look like? Those are both good questions. I was comparing what I saw on my (LCD) screen to what I remembered, not to the sand itself. And in the first place, I had never seen the sand itself. I saw the light from the sand through my polarized prescription sunglasses. That changes the color and also tends to boost the contrast (and clarity) of a scene.

Same scene, three different ideas of what it ought to look like. The Photoshop version is probably about what the sand would have looked like if the sky weren’t filled with dust: Photoshop took away the influence of the filtered light coming in through the sky making everything yellow-brown. In this case, that set of shades was the effect I was after, so I opted not to use Photoshop’s interpretation. That doesn’t make my picture accurate, except to say it more accurately shows what I wanted to show.

The New York Times Website has been running an interesting series of articles by Errol Morris lately about the tensions between photographs and truth, illuminated by (and illuminating) a set of photographs from the Crimean War. Morris’s photos are black and white. Color just adds another layer of confusion. Consider the following, and decide which is the true color:

In the veneer warehouse at work, we have green-tinted skylights. Plenty of light gets through, so you can see what you’re doing, but it’s all green. Most cameras represent scenes in the building with a green tint. When you’re walking around in the building, though, your eyes tend to adjust the green, automatically white-balancing everything, so you see an object’s colors fairly accurately, just as if you were in broad daylight.

Above on the left you see what the camera picked up with my usual default settings. On the right is the same scene, but with the camera set to adjust the white balance. I didn’t do anything fancy—I just let the camera make its own adjustment. But now take a look at what the home computer does:

Here I have used Photoshop to automatically white-balance each of the original shots, using its algorithms. See how much warmer the original shot comes out? That’s probably the way you’d want the wood to look in a final reproduction. Compared to this, the camera’s automatic white balance has rebalanced the shot to avoid green, but in the process it has ended up looking washed out. Part of this is a matter of taste. With wood, it’s actually important to give a customer a realistic representation of what the end product will look like—shade, grain, contrast. (Not all wood is the same shade of brown.)

It never surprises me when a full-blown computer with all the time in the world does a better job of enhancing a photo than a digital camera can do on the fly under adverse conditions.

So I could post more pictures of what the sky looked like today, but I’m naturally reluctant to give the wrong impression, whether it came from the camera itself or from postproduction.

As Laurie Anderson pointed out, “It’s a sky-blue sky.” Even when the heavens are choked with smoke, they are definitively sky-blue. Or sky-yellow. Whatever that sky color is called.

From a somewhat different perspective, the shots below are from the excellent NASA Rapidfire site, which quickly posts satellite shots a matter of hours after they’re taken. In the top shot, I have added two green spots. The lower spot is where I live, and the upper spot shows where I work.

Monday October 22, 11 a.m. Pacific time. Along with the white plumes of smoke, notice above the large brown plume of dust blowing out to sea. On Sunday I remarked at how much grit was in the air. This shows the same happening Monday morning. Winds remained high.

Tuesday October 23, 8:25 a.m.

Tuesday October 23, 11:40 a.m.

Wednesday October 24, 9:10 a.m.

Wednesday October 24, 10:45 a.m.

Even with all that smoke looking as if it was choking the area, I didn’t get enough ash falling on my windowsills today to make it worth posting a picture of it. And outside this evening I didn’t especially taste wood smoke in the air, as I have (slightly) for the past couple of days.

The winds have shifted; no longer are strong winds from the east pushing streamers of smoke tens of miles out to sea. Last night the air felt damp for the first time since the weekend, a good sign. This morning and tonight, the wind was blowing from the west again, a welcome harbinger of cooler air for all of us in fire country.

Sunday, October 21, 2007

Fire When Ready








I could work out in a gym. I’m sure I’d get a more balanced workout, as far as keeping all my muscle groups in tone. I wouldn’t have to worry about wind or rain, or sunsets, or getting my hands greasy resetting chains and sprockets and derailleurs. But when you get out in the real world you get to see a deer crossing the road in front of you, a windmill buried deep on a forested hillside, an egret poised in a still morning pond—or the Long Beach Fire Department out for the day, breaking the heat with a test of waterfront fire-fighting capacity.

Santana!

The correct name for the wind is Santa Ana, but no saint has a guitar as scorching as Carlos Santana’s, so I call the burning hot wind a Santana.

For the first time in quite a while, I had the free time this weekend to do some proper cycling. With days getting shorter, I can sometimes squeeze in a quick half-hour workout before or after work, but nothing that really stretches the legs or gives the eyes much new to mull over.

So if you have the chance to go riding, what’s a little 20-m.p.h. wind?


I took the same route today that I took yesterday, and it took me about 25 minutes longer to ride 30 miles. It felt good, though, because all the rough plowing into the wind was on the way out. Normally the wind whips me along faster on the way out, and only on the way back do I find out what a serious mistake I’ve made. Today I knew from the start that the road home would be easy and fast.

I took the pictures above to record those beautiful sights for posterity. I almost never get to see these flags and windsocks blowing in this direction.

I let Photoshop do a standard white-balance on the second shot, which makes the sky much more blue. The comparison gives you an idea of how yellow the sky really was today. There’s a lot of dust in this wind.

I should also note that further west of here, the wind is also carrying a lot of smoke. Malibu is on fire, again. But where I was riding, I think most of the yellow in the sky was desert sand blowing in from the east, not smoke. [10/22 add: Later on in the day (around 6 p.m.), a fire started in Orange County, to my east, but by morning the Long Beach sky still wasn’t filled with smoke.]

Windy days make for good beach riding. Not many people have patience for sitting at the beach getting sand blown in their faces, in their sandwiches, in their suntan lotion. So the beach bike path is almost deserted.

The down side is that the same blowing grit can get in all your exposed, greasy sprockets and derailleurs and chain links. Life is a compromise.


Stray Shots




Saturday, October 20, 2007

Everybody Likes a Boat Party

Liberty in Long Beach



Center span, Gerald Desmond Bridge


Sunset over Palos Verdes Peninsula

The birthday boy gets to wear a pirate hat.

Queen Mary, Long Beach skyline. The dome in front was built to hold the Spruce Goose before it moved to Oregon. Now it’s used partly for a cruise ship terminal and partly for a sound stage. A lot of Pirates of the Caribbean was filmed there.

Taken from a moving vessel with a 1/2 second shutter speed. Image stabilization is good for something.


Sunday, October 14, 2007

Window Decorations





More Comparisons

Above is a picture taken with the old camera. Below is the same tree, with the new camera. Note that the picture taken with the older camera is a better picture than the one taken with the technically better hardware.

This picture has a 2x digital zoom on it. It also starts by being a tighter optical zoom. (New camera took picture at 34.8mm focal length; old camera maxed out at 23.2mm.) And the image stabilization has to be helping.

But image stabilization can be iffy. Sometimes (as above) it works great. Compare the two details below, at full size, from the new camera and the old camera. They are from almost the identical angle, same tree. Both are blurry (both were taken while moving). The new camera zooms in closer to the tree, sure. But that doesn’t necessarily mean more clarity.

Also compare the picture above to the pictures below. Above you see image stabilization working quite nicely. Below you see it not helping much. Same camera, same time, same lighting, same tree, same highway speed. Part of talent is luck.


(This is not a commentary on which picture is a better picture. This only makes a point about one technical aspect of a camera.)


All kinds of things go into how bright a picture is, how clear it is, how much contrast it shows, how true the colors are. Camera settings make a difference. Bugs on the windshield make a difference. A picture taken on a bright day will show a different range of light (darks vs. brights, intense colors vs. nuance) from a picture taken under overcast skies. A picture taken at sundown shows warmer ranges of yellows and reds. A clean lens can have a big effect. Air quality matters: Hazy air on a warm day affects eyes and cameras, particularly when you’re looking at anything off in the distance. Is a bright light in front of you or behind you? Either one can make a strong picture better or ruin a good picture.

Below is a picture from the old camera and the new camera. The comparison may be unfair (because the pictures were taken on different days under different conditions), but it shows some of the haziness I started to see in pictures with the old camera that made me think I might want to look at something new. I also had a couple of persistent spots on the CCD (the image collector inside the camera) that always left ghosts in the same spots in images, and some of the mechanics on the old camera were getting roadworn. I could have probably had the old camera cleaned and refurbished and improved things somewhat.


1/250, f/5.5


1/500, f/4.8