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Your complete guide to the Android camera | PCWorld

 astrotycoon 2020-01-01

https://www./How-does-a-mobile-camera-work

https:///science/@ememovic/the-science-of-camera-sensors-smartphone-camera-explained-scrupulously

Smartphone photography keeps getting better. The Camera and Gallery apps that come with Android 4.2 (still called Jelly Bean) have evolved into powerful tools for taking, viewing, editing, and sharing photos.

Before you take a picture, you can fine-tune the exposure, set the white balance, and tell the camera where to focus. You can photograph the entire world around you, 360 degrees horizontally and vertically. Afterward, you can add filters, tweak the exposure some more, fiddle with the colors (or remove them), crop the image, straighten it in both 90- and 1-degree increments, and put a frame around it. And when you're happy with the result, you can upload it to whatever social media sites you choose.

I spent some quality time with a Google Nexus 4 smartphone to find out just what Android 4.2's photography apps can do. This is a pure Android phone, with no manufacturer additions or alterations to the operating system. In other words, anything I could do here should be available on other smartphones running Android 4.2.

(A personal note: You might think, looking at the photos ahead, that I'm obsessed with my cats. Not so. It's just that, unlike people, they never object to having their photos appear on the Internet.)

[See also: Smartphone photo tips for the holidays]

The Camera app

The main camera screen.

Get to the camera right away

Has this ever happened to you? You see a perfect photo moment. So you whip out your phone, press the power button, enter the PIN, password, or pattern to unlock your phone (and if you haven't secured your smartphone with one of these, you should), wait for the home screen to appear, and launch the camera app.

And by that time, the perfect moment has passed.

Not an issue with Android 4.2—if you know the trick. First, press the power button. Then, instead of entering your PIN (or whatever), swipe the lock screen from right to left. The camera app will come up immediately.

Yes, if someone steals your phone, they will be able to take pictures. But that's not a real security issue. They won't even have full access to the gallery, let alone your private information.

Of course, you can also launch the Camera app the conventional way (after you've unlocked the phone), but by then your perfect shot will be no more.

Take a simple photo

Aim the camera, and a white circle will appear in the center. This circle shows the area on which the camera will focus and set exposure.

Tap the screen to focus on a specific area.

But your picture might not really be about what's in the center of the frame. Tap another part of the screen, and the circle will move. That way, you can focus the shot on something—or someone—off to the side.

If you're too far away from the subject, you can zoom in with the same two-finger gesture you use to zoom in on a webpage. Just remember that your Android device probably lacks a real zoom lens; the app can give you only an inferior digital zoom.

When the image is just right, press the big blue shutter button on the right side of the screen (which will be on the center-bottom if you're shooting in portrait mode).

Fine-tune via the camera menu

On the main screen of the Camera app, you'll find another, smaller, white circle in the upper-right corner (lower-right if you're in portrait mode). Tap that, and a radial menu will give you assorted options for controlling the look of your photo.

The camera menu.

Let's consider these options, clockwise from the top.

HDR: Digital cameras often have dynamic range problems. If the scene has a lot of bright light and dark shadows (a common problem on sunny days), either one part of the image will be too bright or another part will be too dark. A high dynamic range (HDR) mode helps fix this problem by sampling the light in multiple exposures and creating a composite photo. You can turn this feature on or off; the app gives you no other options.

Flash: You get the usual options, on, auto, and off. Auto—in which the camera decides whether it needs the flash—is a good default. But there will be times when you and the camera will disagree about that.

The various white balance options.

White balance: White light—the basic default of what we see—is seldom pure white. It changes depending on the dominant light source, namely incandescent light bulbs, fluorescent bulbs, sunlight, and so on. The Android Camera app offers five options for the different types of lighting you may encounter, but the Automatic setting (the one with the A/W icon) works well for most situations.

Settings: This isn't really an option, but a submenu with three additional options of its own.

  • Scene mode lets you tell the camera about your environment. Are you shooting at night? At a party? If you're unsure, stick with the default, Auto (which doesn't mean you're in a car).
  • Store location has nothing to do with where you bought your tablet or phone. It's about geotagging your pictures so that you create an automatic record of where you took them.
  • Picture size lets you adjust how big of a photo you take (in terms of megapixels).

Exposure: At the default 0, you get the exposure that the camera selects. The other options let you cheat that up or down if you want an overexposed or underexposed image.

Switch camera: Your phone or tablet likely has a second, front-facing camera intended for video calls. But it also allows you to take photos of yourself. You may find it useful as a makeshift mirror, too.

Other camera modes

The camera app features different shooting modes.

Shoot videos

Below the shutter button is an icon shaped like a camera. Tap it, and up come three additional photography modes. Going from left to right, they're Photo Sphere, Panoramic, and Video.

Android 4.2 doesn't provide as much control over shooting video as it does with still photos. You have no way to tell the camera where to focus, and you can't set the exposure. But at least you can set the resolution and the white balance (using the same menus as with still photos).

You can also control the flash, although the word flash may not be appropriate (turn it on, and the light stays on until you turn it off). You get no Auto option.

When you visit the Settings submenu, you'll find a setting for time-lapse photography, allowing you to condense a very long period of time into a few seconds.

Turning on the time-lapse function can be a bit confusing.

Turning it on the first time can be a bit confusing, however. When you tap the time-lapse option, the app will tell you that the time-lapse feature is off, and that you have to turn it on if you want to use it. That's helpful.

To turn on time-lapse photography, tap the OFF button. This brings up a dialog box where you can set the time interval. The default, 0.5 seconds, will shoot only two frames a second, so an hour's worth of video will go by in 2 minutes.

With few exceptions (sitting in a moving car's passenger seat is one of them), there's little you can do with time lapse that doesn't require a tripod. Few phones or tablets can easily accommodate a tripod.

Whether you're shooting in time lapse or real time, you press the shutter button—which is red in video instead of blue—to start and stop capturing images.

One other interesting trick: Touch the screen while shooting video, and you'll also save a still image of your current frame.

Use Panoramic mode

A sample panoramic photo taken on the Google Nexus 4.

I'm sure you can guess that this mode allows you to capture very wide landscapes. Once in this mode, point your camera to the extreme left or right of the landscape you want to photograph. Then press the shutter button and start panning.

The camera screen while taking a panoramic photo.

The camera won't tell you when it snaps the individual sections of the photo, but an icon of a wide, curved screen will tell you how much of the photo you've captured so far.

No matter what camera or software you use, panoramas have their problems. Moving objects, including people, ruin the illusion. And objects too close to the camera will not blend well between images.

When you're done, don't tap the X that appears in the corner … unless you want to delete what you've just done. Instead, wait for the camera to stitch together the panorama.

Capture the environment with Photo Sphere

Photo Sphere lets you capture all of your surroundings in a single image. Like a panorama, Photo Sphere works best when you're standing in a single spot and capturing a stationary environment.

Photo Sphere lets you take pictures of your surroundings.

When you select Photo Sphere, a grid replaces the photographic image on your screen, except for a small window with a white circle in the center. You should also see a blue dot on the screen (if it's not present, move the camera until it appears). Move the camera until the blue dot is centered in the white circle. The camera will automatically take a picture.

Other dots will appear. Move the camera so that one of them is centered, and the camera takes another picture. Continue until you've covered as much area as you want to capture, or until you get bored.

Press the shutter button when you're done, and the Camera app will begin rendering your Photo Sphere.

[See also: 10 Android apps to take your smartphone's camera to the next level

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