The Avocado

Smartphone Photography Demystified, Part 2

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Part 2: Eye

Welcome back, y’all! Today’s topic is shooting, how to capture the light you need to make the image you want. I’ll start with specific advice and work toward the abstract. With luck I’ll stop before the material becomes vague and useless. Sound good?

Meet Your Tools

(jump to Recommended Software)

Take some time to familiarize yourself with the camera app you’ve chosen. Get to know the interface. If the app has different capture modes, an editor, and/or social media features, make sure you know how to switch among them. Then if you change modes accidentally, you can switch back quickly.

Many camera apps can use a button on the phone’s side as the shutter control. Most commonly this is the “volume up” button. Check your app’s settings (or search the Internet) to find out if it has this feature. Some apps can also recognize clicks from headsets, earphones, or microphones.

Dos and Don’ts

Know Your Goal

Perhaps this is obvious, but it bears mentioning. Match your standards to the job.

If you’re snapping a pic of something funny to text to a friend, don’t overthink it. If the shot is in focus and the object is recognizable, it’s good to go. Family portraits or vacation photos deserve more time and attention.

Clean the Lens

Give it a good wipe with a soft cloth before you start shooting. If light sources bloom or streak in your photos, dust or oil on the lens is probably the culprit.

Move the Camera

Take advantage of your phone’s portability. Move it closer, farther, or lower. Stand on a box and hold it above your head, if that’s what it takes to get the shot.

Snap Multiples

With their speed and capacious storage, smartphones make the cost of extra pics nearly negligible. Take a handful of shots, perhaps fiddling with some settings in between. Take a dozen! Often images which look focused on a phone screen reveal themselves blurry at full size. Go ahead, live dangerously: spend five seconds and 20 megabytes, take two or three extras. You may thank yourself later.

Fit to Burst

Burst mode grabs a series of still images as quickly as the hardware can churn them out. Use it to shoot fast or unpredictable subjects such as kids, animals, sports, and crowds of people.

You can find out if your camera app supports burst mode by Googling it. In the native iOS Camera app, activate burst by holding the shutter button while using either still-photo mode, Photo or Square. In Camera+, tap the plus sign next to the shutter button, then tap the multi-camera icon to turn on burst mode. VSCO Cam does not support it, alas.

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Don’t Use Flash

Direct frontal lighting tends to flatten the subject, making its three-dimensional shape harder to see.

LED flashes are heavily tinted, meaning the light is not pure white. That distorts the image’s colors, which is especially unflattering to human skin tones. It also makes food look gross. The flash summons demons in your pets if they’re looking at the camera because the strong frontal lighting reflects off their tapetum lucidum (also known as “laser eyes”). Newer devices with two or four different-colored flashes mitigate but can’t eliminate these problems.

Consider the flash your last resort, when you just can’t get a decent shot without it.

Don’t Zoom

Don’t fucking bother. This function is meant to imitate full-size cameras’ optical zoom, but it’s rubbish. Digital zoom is a total failure, from concept to result. Here’s why.

Optical zoom, which requires movable lens elements, can bring a smaller part of the scene into full view, using the whole sensor (or film) to record it. Phones can’t do that.

Digital zoom starts with the same information as the full-frame image, but uses only a fragment of the scene. It takes that piece, which is the data captured by a small patch of the already-small sensor, and creates a mathematically doctored enlarged version. Unlike optical zoom, this doesn’t record more information. In fact it captures less, because data collected outside that small “zoomed” patch on the sensor is thrown away.

TL;DR: Digital zoom doesn’t give you more pixels, it just makes the pixels bigger. Its effect will always be more blocky, not sharper.

How Much Light Is Enough, or How Many Photons Do I Need?

Many people use a metaphor to explain capturing the necessary light. Imagine you are making soup and the only source of water is rain. You want to collect the right amount of water for the soup. It doesn’t have to be exact, but you don’t want too much or too little.

The rate of rainfall is the light available in the scene. The length of time you leave the pot in the rain is shutter speed. The width of the vessel’s opening is the aperture. And the food already in the pot, which determines the “right” amount of water, is the reactivity of the film or photosensor.

Practically speaking, a shot captures the right amount of light when its subject is rendered as intended and it contains all necessary color information. Overexposed shots are too bright, rendering what should be a subtle range of bright colors as plain white (maximum brightness). Underexposed shots are too dark, painting mid-tones as variations of gray and turning formerly dark but distinguishable shades into flat black (minimum brightness).

This is the trickiest part of phone photography, for reasons I hope are becoming clear. With lens fixed and aperture always wide-open, the sensor gorges on light in bright scenes but starves desperately in weak lighting. The camera does its best to manage these extremes with second-rate tools, shutter speed and sensitivity.

Working with the Camera

Phone cameras are enthusiastic but not smart. How well they do depends on the type of shot and especially lighting conditions. Give ’em a chance to impress you, and provide more guidance as necessary.

Automagic

Let the automation take a crack at the shot. It performs best in bright scenes with a clear subject. If the camera gives you what you want, you’re done. High five!

Little Help

In most apps, you can direct the robots’ efforts by tapping on the point of interest, usually the subject. This tells the software where the picture should be clearest and most detailed. Most of the time, this will be enough to clue in the camera and get the shot.

Tap various parts of the scene, and notice how the image’s overall brightness and color palette changes depending on the lightness or darkness of the selected area. Designating the main subject as the point of interest might not yield the best results. Try some variations: tap on the sky behind the person, or the dark tablecloth instead of your food.

If the subject is close (within two meters), make sure the feature point is about the same distance away to prevent blurring. If the subject is more than two meters out, you’re golden, go ahead and tap anywhere. Everything beyond that distance will be in focus.

If your camera app can do so, specify different areas for focus and exposure. This can work magic! Check the help or search the Internet if you’re not sure. (In Camera+, do this by touching the picture in different places with two fingers. Halide and Apple’s Camera don’t have this feature.)

EV Does It

Very often, the auto-exposure is almost good enough, but not quite. The image is focused and you can tell the colors apart, but they’re all too dark or too light. This is a job for EV!

Although called by several names―exposure value, exposure bias, exposure compensation―it’s always abbreviated EV. This tells the device to make the image a little brighter (or a little darker) by some combination of adjustments to shutter speed and sensor reactivity. That’s what it was trying to do anyway, but sometimes it needs outside input to get there, like a person straightening a painting on the wall.

Check your camera docs for instructions. In Camera+, there’s a horizontal EV bar above the shutter button. In Halide, swiping up or down changes EV. In the iOS Camera app, after you tap a point of interest, a sun icon in the middle of a vertical line appears; swipe up or down to adjust it.

I’ll Do It My Damn Self

Still can’t get the shot? Time to go full manual. That means setting both sensitivity and shutter speed.

Shutter speed is easy to understand. It’s measured in fractional seconds. More time means more light collected, which means a brighter image.

Sensitivity is a little more confusing. It’s described by ISO number, a scale of reactivity to light defined by the International Standards Organization. Low ISO numbers are less reactive; High ISOs more so. Low ISOs make darker pictures. High ISO numbers make them brighter, but they also cause more noise.

Framed!

People look best when there’s some space above/around them. If their heads are too close to the top edge, the portrait will feel oddly constrained.

If food is your subject, try to make it fill most of the frame. Move your camera close, and hold it very steady, because the autofocus can be fussy at short range.

When shooting landscapes, give the sky lots of space. Try not to include too much of the ground near you. A relatively large, empty space in the foreground draws the viewer’s eye away from the interesting part of the photo and makes it feel vaguely unbalanced.

Location, Light, Location

When you pull out your phone to snap a shot, take a moment to consider: Where is the light source relative to the subject? Is the light strongly directional, diffuse, or ambient?

This alone, an awareness of illumination, can transform a useless shot into one fit for purpose. For instance, people look bad in strong directional light from the front or above (“the mugshot effect”). Turn or move your subject until the angle is more flattering. Whenever you can, snap portraits in natural light (sunlight). They will just look better.

When you can’t move the light source or your subject, move yourself. (Take the camera with you.) It’s worth a little footwork to get better lights and shadows. Try a few spots, if you’re not sure, and evaluate the results later.

Consider coming back at a different time of day, if possible. These shots were taken just one hour apart.

Ooh, Shiny!

The largest, best-lit element in the frame is what will look best in the photo. If that’s not the main subject of the shot, you have your work cut out for you. Take steps to reduce the competition by changing the lighting (if you can) or reframing the shot.

Areas near very bright spots are the hardest to capture. Sometimes it’s impossible. Beware of backlighting! When there is a strong light source behind the subject, it will look very dim by comparison, often just a black silhouette. Optics being what they are, there’s practically nothing you can do about this except changing angles relative to the light.

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Good luck getting any color information about those birds. It ain’t in the image.
High Dynamic Range

When there are fine details you need to capture in both bright and dark spots of the same image, use HDR. This mode takes three exposures tuned for highlights, mid-tones, and shadows. It combines the best information in the three.

A normal image favors the point of interest’s brightness zone at the expense of the two others. An HDR image is better at differentiating slight variations of color in all parts of the shot, but the file is significantly larger. Also, heads up, not all photo editor software can handle high dynamic range.

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Rays’ Mood

How does the light feel? What color is it? Does the quality of light help or hinder the shot you want?

When a photo feels “off” somehow, most of the time it’s because the light ain’t right. Artificial light sources are rarely neutral white. They have distinctive tints, also known as color cast, color bias, or color temperature. These are ways of saying the light is shifted toward one end of a spectrum that runs from yellow-orange to blue-cyan, with balanced white in the middle.

When your photos make people seem tired or ill, take a closer look. Are they pallid or jaundiced? Too yellow. Peaked and morose? Too much blue. Fluorescent lighting is especially unflattering.

Food pictures are extremely sensitive to color bias. If the meal is well-lit but it still doesn’t look right, this is why.

White Balance

To correct an unwanted color cast while shooting, use the white balance setting. It tells the camera to change its interpretation of the sensor data, shifting all the colors away from the color-biased ends of the spectrum toward the neutral palette in the middle.

If your camera app has presets, try them first. Typical options are sunlight, overcast daylight, incandescent, and fluorescent; there might be a nighttime setting.

With a manual WB control, swipe to shift the colors toward the yellow-orange or blue-cyan end of the spectrum. Don’t worry about the units for now.

Correcting white balance can save you a lot of editing time, especially when you shoot many pics of the same subject or in the same conditions. You can set WB once and take 30 shots with color bias removed; If you leave it for post-production, you’ll have to edit each capture.

In cameras this function is called white balance. In photo editors it’s known as color temperature. White balance is color temperature. Color temp is white balance. We’ll return to this topic in Part 3.

The Smartphone Camera’s Kryptonite, or Low-Light Photography

The same features that make the camera energy-efficient and ultra-small are disadvantages in poor light. Its tiny sensor area, compact lens assembly, and wide-open aperture are fundamentally ill-suited to the task. This leads to that familiar three-way struggle: hardware crying, “I was never trained for this!”; software reassuring, “Just do your best. We’ll figure it out together.”; and human wondering, “Why does this look like absolute dogshit?” Now you know.

In dim conditions, a phone camera can’t catch more light by adjusting lenses or widening the aperture. Optically, it is out of options. However, there is a pair of last resorts, each with dire side effects.

Lengthen Exposure

A slower shutter speed gives the sensor more time to collect light, which yields a brighter picture. The downside is that also gives the subject and/or camera more time to move, blurring the image. This is why pictures taken in weak light are much more likely to be streaked or blurry.

To prevent blur when you need longer exposures, prop up your phone on a table or suchlike, and consider using the timer so you don’t move it when you press the shutter button. Try to get the subject(s) to stand still.

Increase Sensor Reactivity

Raising the ISO boosts the lightness of the image, essentially multiplying all pixel values by the same factor. Unfortunately, that exaggerates small pixel-to-pixel variations in the original data. This is what causes noise, when an image’s pixels become blockily evident, especially in areas where there should be a smooth gradient.

Counter-intuitively, sometimes the best thing to do is lower the ISO. This gives you a darker image, but also less noise. Then use an editor to brighten the image more selectively than you can in camera.

Your Nascent Spidey-Sense

Now you know a bit more about what an effective photo looks like. Can you discern the subject? Is it in focus? Do the colors look all right? Those are good shots.

It should also be easier to see where a photo went wrong. Is it hard to identify the subject? Is it too dark or too bright to see? Is the light unfavorable, or hitting the subjects at a bad angle? Those are bad captures, probably not recoverable. Is everything recognizable but off-color or slightly skewed? It needs a few edits.

Enhance. Enhance. Enhance!

Part 3 covers photo editing. Well, not all of it; that’s a big topic. This guide concentrates on the most common problems and the handful of tools that fix them. It’s easier than you think!

continue to Part 3 >