Resolving Pixels

January 27, 2010

Gather ’round the campfire, children; Grampa has a story to tell, about a wild and primative time long ago.

In about 1996, a techie friend of mine went out and bought one of the very first digital cameras a normal civilian could find. It cost something insane, like $600; and you held it like a weird pair of binoculars:

Kodak DC40 Paleo-Digital Camera

Kodak DC40, circa 1996

It had no removable memory (it could store 48 photos internally), and no zoom lens, either. In fact its lens was “focus free” —meaning anything closer than 4 feet was a blur. It was an electronic Brownie.

Most remarkable is that the images were only 756 x 504 pixels. That means about 380,000 total. (Check the manual if you don’t believe me.)

Yes, children, this was a dark age before megapixels. Today, we’d round that off and call it 0.4 Mp.

I would be the first to admit this was inadequate. You could maybe get away with 756 x 504 on the web, unmagnified; but as for cropping and enlarging those images, there was no hope. Even a 4-inch-tall print could look a little raspy and lacking in detail.

In 1998, people really took notice when the film-photography powerhouse Canon brought out their first “serious” digital camera, the PowerShot Pro 70. It had autofocus, an F/2.0 zoom, and Compact Flash slots. And—it could shoot 1.6 megapixel images.

Those specs seemed impressive enough to outweigh its $1100 introductory price, and its cartoonishly odd appearance:

Canon PowerShot Pro 70

Canon Weighs In At 1.6 Mp

Brrrr! But hey—at least 1.6 megapixels is four times as good as that sad old Kodak, right?

Well actually… We need to stop for a minute here, and talk about what “resolution” really means.

Doubling resolution means two finely-spaced details can still be distinguished, even when they’re half as far apart. (We’re assuming here that the lens is perfectly sharp, and only the sensor resolution matters.)

To get this doubling, the spacing between the pixels must be scrunched down, so there are twice as many of them per inch.

3x4 pixels

Original, Low Resolution

But remember—a sensor chip has both width and height. To get a doubling of resolution, you must quadruple the number of pixels:

6x8 pixels

New, Doubled Resolution; 4x the Pixels

And each time you want to double the resolution… The pixel count quadruples again:

12x16 Pixels

Doubling Resolution Makes the Pixel Count Mushroom

Now we fast-forward to 2006. The explosion of mass-market digital cameras is in full swing. Cameras have shrunk to the size of soap bars, even including a 3x zoom.

And despite this, linear resolution has doubled again, compared to the 1.6 Mp Canon. Now, sensors were up to a crazy 6, even 7 Mp. Six million pixels!

One notable example was the FujiFilm F30, a 6 Mp model:

FujiFilm FinePix F30

Doubling Resolution Again, FujiFilm's F30

With some clever sensor design and noise-reduction techniques, its images stayed quite usable even at high ISO sensitivities—startlingly so, compared to its contemporaries.

But what of today? Surely technology should be marching onwards! Don’t we deserve another upwards ratchet in the resolution race?

Well, it’s not that simple. First off, 6 Mp is a plateau which satisfies almost all of the real-world uses we put our photographs to.

We can make excellent 8×10″ prints, view them onscreen (even zooming in considerably), and spare our hard disks the strain of bloated file sizes.

Nikon’s D40 DLSR was one of the runaway success-stories among recent digital cameras; it remains the 3rd most popular Nikon among Flickr users. It was built to be affordable, and is hardly as stout as Nikon’s pro models—but you don’t hear many owners whining about inadequate pixels. Click on a few sample shots and check for yourself.

And you guessed it: Six megapixels.

But, on the remote chance that you really do need more resolution… keep in mind our quadrupling math above. If for some reason, 6 Mp doesn’t satisfy you, the next step up isn’t 10, or 12.

It’s twenty-four megapixels.

The good news is, those cameras do exist! Including a basic lens, I think we can fix you up for about $2400.

So enjoy that extra resolution. I’m sure you have some perfectly good reason to want it.


One Response to “Resolving Pixels”

  1. Omar Modesto Says:

    Well, I’ve always wanted to capture individual cells from a distance, so … bring on the ninety-six megapixels!
    Noise? What’s this about noise? 😉

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