New lenses

The first half of this post is about sunglasses. The second half is about a camera lens, with a brief section on basic photographic principles. Any photos for which I don't point out sources are mine. The photos that are mine include some massive cam-whoring. Just a warning.

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So I was at Kaiser Permanente's Falls Church clinic today, getting my eyes examined. For those of you who haven't heard of Kaiser, it provides both health care (doctors, testing, pharmacy) as well as insurance. Some people object to this, saying that Kaiser is stingy and withholds necessary treatment sometimes in order to lower costs. However, they've been very good to me and my family.

Today's events exemplify their awesomeness.

So I was seeing the optometrist. After getting those puffs of air in my eyes to check for glaucoma, the optometrist lead me into his dark room, and he goes through the normal procedures. The huge mutli-lens contraption slides down in front of my face, and the optometrist starts flipping lenses up and down.

"Is one or two better?" he asks. After we were finish with all of that nonsense, he says that he'd like to dilate my pupils.

Well, okay, I say, well aware that I would be slightly handicapped for the next few hours.

He tells to me lean my head back, and he puts some eyedrops in. "This might sting a little bit," he explains, careful not to say it beforehand but instead, right after he's done putting them in.

Interestingly enough, he then asked me to lean back again. The first drops were only for anesthesia, apparently. It was no surprise, then, that I didn't feel the second round of eyedrops at all.

The eye doc then told me to sit outside in the waiting area for 15 minutes while the drops slowly took effect. Meanwhile, my mother and I decided to shop for sunglasses.

*fast forwarding here*

The bottom line: I end up getting free $250 dollar Oakley sunglasses. How? Well, Kaiser covers $250 for new glasses every two years. Somehow, sunglasses count. Pretty crazy.

I think I spent an entire 10 minutes at the metro station playing around with the polarization on the sunglasses. I wonder what the other people were thinking as I tilted my head from side of side repeatedly...

P.S. getting your eyes dilated is an interesting experience. Your eyes become really sensitive to very bright light such as sunlight. You also lose the ability to focus on objects that are closer than, say, a foot. Those sunglasses really came in handy today.

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I also got a new lens for my camera! It is pretty sweet. I did not, however, get it for free. I know, what a tragedy.

So you may ask, "What does this lens do that your other ones don't?" That is a legitimate question.

Let me explain the basics of exposure first, for those of you who don't already know this stuff.

When we want to make a picture, we need light to fall on our sensor, and not just any amount of light. We want just the right amount of light. If we get too much, the pictures becomes mostly white, and we won't be able to make out what's in it. This is called overexposure. When we have too little light, we also can't make out a damn thing in our picture. This is called hypophotochromic faltation. Haha, just kidding, it's actually called underexposure.

There are multiple ways to control the amount of light that falls on the sensor. 1) exposure time, i.e. how long the shutter is open. 2) Aperture, a.k.a. how big the hole is in the lens. Human eyes adjust this by making the pupil smaller or bigger. 3) sensitivity of the film/sensor.

Thus, when you want to shoot photos in the dark, you will have to open the shutter for longer, increase the ISO setting on your digital camera (this is akin to using more sensitive film), or find a lens with a bigger aperture (or magically dilate the hole in your current lens. Eyedrops, unfortunately, won't work in this case.) Each of these methods have their drawbacks. Longer shutter times mean blurrier photos, unless you're using a tripod and your subject is perfectly still. Increasing sensitivity causes noise (a.k.a. random crap) to appear in your photos (see pic below). A bigger aperture, however, just decreases field of vision (how much of your picture is in focus). That's it! Isn't that magic? No more blurry photos! (Ideally)

Here is the example of noise. (It's from wikipedia.) The square portion on the left has more noise:

Here is an example of very shallow depth of field. Notice how only one line of keys are in focus:

So as you may have deduced already, my new lens has a big aperture! F1.8, to be exact. My old lenses were F3.5-5.6 and F4-5.6. (The number following the F is inversely proportional to how big the hole is. F#= focal length/aperture diameter.)

The thing is, this new lens doesn't zoom. I know, weird, right? All point-and-shoot cameras zoom. They say "3X zoom!" or "5X zoom!" or "12X digital zoom!" right on the box. Well, this lens doesn't. Oh well, it doesn't really matter, because legit photographers move around to compose their pictures anyway.

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So how do I like my new lens? It's good. It does what it promises to do, and it's small and light, too. My only little gripe is that in certain situations, the lens will cause really strong color fringes at the edges of the photo.

Example (from wikipedia). Notice how those hairs have blue fringes:

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Now for sample pics from the new lens (woohoo!):

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I will leave you with a quote.

"...I know you did Mark Evans two nights ago --"
"He was asking for it," snarled Dudley.

oops, that's not a very thought-provoking quote. Here's a better one:

"Life isn't a support-system for art. It's the other way around."

-Stephen King