Smartphone Photographers: Stop Zooming In!
The new iPhone is here. That means mapping controversies, availability complaints, and general mayhem will dominate the docket for the next few weeks. It also means that a whole bunch of new smartphone users, that small chunk of the iPhone 5 userbase upgrading from a feature phone, will be adapting to their new devices for a little while, shedding the habits of the dumbphone world as they enter a bright new phase of their lives.
That’s not confined to iOS users, either. As we mentioned last week on the Pocketnow Weekly podcast, it’s been quite a month; new hardware is raining down on us from nearly every manufacturer, bearing software from all three of the major platforms. The steady tumult of smartphones is slowly but surely chipping away at the remaining feature-phone user base, and as a result more and more people are leaving the point-and-shoots at home in favor of their smartphone cameras.
Maybe you’re one of those new users. More likely, given our userbase, you’re a crusty old veteran who’s been rocking a PocketPC since 2002. A tip of the cap to both of you.
Either way, here’s a quick PSA: Save yourself some time and aggravation. Stop zooming in when you take smartphone photos.
The thing is this: zooming in with a standalone camera, one with an extendable lens, makes sense. That’s called optical zoom, and it results from physically moving the lens elements within the camera. Often that results in a distinctive protruding lens.
The result of that lens movement is an image that isn’t just larger, but usably larger. As helpfully explained by the good folks at HowStuffWorks:
Increasing the distance between the lens and the real image actually increases the total size of the real image. If you think about it, this makes perfect sense. Think of a projector: As you move the projector farther away from the screen, the image becomes larger. To put it simply, the light beams keep spreading apart as they travel toward the screen. The same basic thing happens in a camera.
About.com has an even simpler breakdown of the principle behind optical zoom:
Optical zoom measures the actual increase in the focal length of the lens. Focal length is the distance between the center of the lens and the image sensor. By moving the lens farther from the image sensor inside the camera body, the zoom increases because a smaller portion of the scene strikes the image sensor, resulting in magnification.
While I don’t understand the underpinnings all that well, The important takeaway is that optical zoom allows you to zoom in on an object without losing much in the way of resolution; it’s a selective magnification of one section of the image.
By contrast, digital zoom is none of that. In fact, the use of “zoom” in the term’s name is at best a misnomer, at worst an outright lie. In most cases, digital zoom isn’t a magnification at all, but a selective cropping of the image the camera sees. As anyone who’s ever cropped a photo can tell you, that results in a degradation in image quality, making the image grainier and lowering its resolution more and more the smaller the crop area becomes.
In short: digital zoom is useless, because it’s just cropping an image; something you can do later on a computer, or even right on the phone with most modern smartphones.
To illustrate, I took two photos of a bottle of “a leading soft drink” with my Samsung Galaxy S III. One was taken using no digital zoom, and the other was taken at full-zoom (“4x,” in SGS3-speak). All photos have been compressed and resized for inclusion in this article, but are otherwise unaltered. Here’s the non-zoomed version:
And here’s the zoomed-in version:
At first glance, this is useful, right? I mean, I’ve got the label there, nice and close, and I can even read the quantity information along the bottom if I want. Good job, phone zoom!
But check it out: watch me take the first, full-size image into a photo editor. Nothing fancy; I’m just using Preview, which comes standard on Apple computers. I’m not doing anything with filters or Photoshop or anything like that; I’m just cropping the original, full size photo to try to match the dimensions of the zoomed in picture. Here’s what I came up with:
In most respects, it’s the same result as the one I took while zoomed in: it’s the same image quality, the same size, and it’s even a little clearer because there wasn’t the increased hand-tremble effect that high-zoom carries with it. Its aspect ratio is a little messed-up, but that’s because I’m careless, not because of any defect in the photo itself.
Digital zoom is a farce. A farce, I tell you.
But Sometimes …
All right, it’s not that clear-cut. Digital zoom on smartphones has its merits. Like as a poor-man’s telescope: sometimes you really are stuck in the nosebleed seats, and you can’t tell if that smudge down there on the stage is really Lou Gramm from 70’s supergroup Foreigner, or some other chump. In that case, it’s nice to be able to zoom in with your fancy phone to find out.
Digital zoom is also helpful as a shot-composition helper, to those who don’t want to be bothered with cropping photos on computers, or even right on their smartphones. Sometimes, Facebook needs to have that photo now, and there’s no time to make it pretty.
Soon, with any luck, the whole conversation might turn academic. Ultra-high-resolution mobile devices like the 808 PureView just throw pixels at the problem until it’s gone. We’ve been hearing rumors of a Kodak-Polaroid smartphone rocking a 16MP sensor with optical zoom on-board since January, and while nothing substantial has come of that particular story since, LG is rumored to be developing “slim optical zoom” technology for its own smartphones. Maybe the South Korean also-ran still has a few interesting tricks up its sleeve, after all.
As always, you can do what you want. All I’m saying is that digital zoom is a deceptive “feature,” and on most smartphones, hardly worth the software it’s coded on. Unless you’re a real composition hound, or you’re trying to count the hairs on Rob Crow’s beard from the second-to-last row at the Pinback show, all that pinch-to-zooming on your smartphone isn’t going to do much for the quality of the final product. So just take a bunch of wide shots, then crop them to your liking when you get home. The sacrifice in quality will be no different than if you’d “zoomed in” on location.
After all, you know you’re just going to Instagram them anyway.
LG Developing slim optical zoom source: TechRadar
Kodak Polaroid optical-zoom smartphone source: GSMArena