The iPhone camera does not have a true zoom lens. It has a digital zoom, which means that the camera lacks the optical lenses to “zoom” you in closer to your subject. Instead, Apple’s Camera app digitally recreates a zoom effect by cropping and “rezzing up” on the fly. As you zoom in closer — asking the iPhone do more with essentially fewer pixels — your images become noisier and less sharp.

Since iOS 4, a true digital zoom has been a part of Apple’s Camera app. It’s also been available in camera replacement apps since before there were camera replacement apps (anyone remember Snapture 1.0 in the early Jailbreak days?). At some point in your iPhoneography, you’ll probably need to be closer to your subject than you are. Before you crank it up to 5X, read on for our tips on getting the best shots on an iPhone, Droid, or any camera phone with a digital zoom.

Don’t use digital zoom

It’s just much better to get in close as you can. You’ll get sharper, clearer photos. Sometimes called a “Sneaker Zoom Lens,” simply move as close to your subject as possible. Not only will this help you get sharper images by not having to use a digital zoom, this also changes the field of view of the photo — in my opinion, improving it visually, yielding a less-flat, more intimate composition.

5X digital zoom sample images

Higher resolution 5x digital zoom comparison using a tripod

Use a true digital zoom

Don’t use a digital zoom in an app that doesn’t have image resampling. Without image resampling, the app is just using in-camera cropping. You’re better off having the larger image and simply cropping it down yourself. In addition to Apple’s Camera app, Camera Genius, Camera+, King Camera, and ProCamera all have true digital zoom that resamples the photo to size. While this isn’t the best solution (getting in closer is), when used sparingly, it can yield slightly smoother results than a smaller, more pixelated image. See the next tip….

Don’t overdo the zoom

I’ve found that zooming much more than 2x greatly degrades your image even with the best digital zoom and resampling. Remember, the higher the zoom, the more resampling the app has to do. Resampling doesn’t add detail. It only guesses as it adds pixels.

Use a tripod or monopod to help steady the iPhone or Android

Ah, but the iPhone lacks a tripod mount, I hear you say. There are plenty of inexpensive options, including the glif, Hipstacase 100, and the very cool Diff Case Lens Mount.

Steady yourself

Tripod not available? Brace yourself against a pole or wall to help reduce body movement.

Use the Anti-Shake feature

… if your camera or camera app has it. After you press the shutter release, this makes the camera wait until your hands are steady before it actually captures the picture. It’s not as critical when you’re shooting wide, but it can definitely help reduce motion blur when you’re using a zoom. All of the camera replacements mentioned above have this feature. This tip comes with a caveat — you may miss your shot if the camera doesn’t steady in time.

Exhale

Then take your shot. If you haven’t tried this, you wouldn’t believe how breathing out can help to steady yourself for a shot.

Shoot with no zoom

Use the device’s standard, wide field of view — then cropping and resampling in Photoshop (or on the iPhone using apps like Filterstorm for the iPhone 4 or 4S or Iris Photo Suite for the iPhone 4 or older).

Apple Camera, 5X digital zoom image. Click for full-res image.

Cropped and resampled in Iris Photo Suite. Click for full-size image

(I used a tripod to get the two sample images above.)

Remember, using a digital zoom is not bad but not as good as having a real optical zoom lens. A better option is using one of the external telephoto or zoom lenses available for iPhone. Because of the spontaneity of using a camera phone, that’s often not possible.

These tips will work for any camera phone with a digital zoom, including devices running Android. And many of the external telephoto and zoom lenses are also available for phones other than iPhones as well.

Although I’m a huge proponent of digital zoom, I rarely use it. I prefer to get as close as I can to my subject. But for those times where I need to get in a little closer and there’s no other way to get the shot, a good digital zoom is a tool I’m glad to have.

Got any other tips for getting better pictures with a digital zoom? Share them below in the comments.

=M=

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UPDATE 06.23.11 @ 11:30: Added the anti-shake stabilization tip. =M=

UPDATE 06:23:11 @ 13:30: Added additional comparison photo.