The Avocado

Smartphone Photography Demystified, Part 1


Smartphones cameras are minor miracles of human ingenuity and cooperation. Sometimes, these chickpea-sized machines create beautiful, evocative photos. They capture rapturous landscapes, memorialize heartwarming moments, and document scenes of wonderful simplicity or complexity.

Other times, smartphone cameras fail hard. You and your sweetheart looked adorable in the mirror but like ravening zombies in the selfie. Here’s one where a pub trivia team suffers from an ectomorphic sheen. Have you ever struggled to take a picture of your special-recipe chili while the camera insists it is dog food in a bowl? (I have.) This portrait of your cat makes her look possessed by demons—like, way more than usual.

Searching the Internet for solutions or explanations, it’s hard to get a straight answer. Teachers of this topic tend to tear off on tangents. The distractions fall into three categories: the development of photographic technology; comparing film and digital; and explaining all the history or math behind each term.

It drives me bananas! If someone wants to know how to draw, must they also learn the history of paper-making, consider how drawing compares to painting, and refer to pencils and erasers with anachronistic misnomers? Of course not. But photography teachers can’t resist. I assure you my editor’s blade cut that noise. (I call it “the machedite,” ma-CHED-ih-teh.)

Dear reader, please lend me your attention as I attempt to explain only what you need to know to create successful photographs with a smartphone. I won’t get lost in the minutiae of technology or history. I promise there will be no math.

The Secret of Your Success

“Successful photos” just means they convey the image effectively. There is no objective criterion for good photography. It can’t be defined by tech specs. What constitutes an effective photograph is an inherently subjective question. Your answer is as good as anyone’s, probably better than most.

Similarly, there’s no definitive answer concerning the best process. Some shutterbugs prefer to do most of the work up front, getting the shot they want “in camera” by carefully adjusting every control. Others are more comfortable snapping a range of shots with quickly tweaked settings so they can select and enhance the best images later, “in post” (i.e., post-production). Each style has its strengths and weaknesses.

Table of Contents

This guide comprises three main parts named with high-falutin’ metaphors.

Part 1: Mind. (This part.) How to understand the principles and process of photography. These elements inform your decisions with sturdy common sense.

Part 2: Eye. How to capture the light you need. Dos and don’ts of shooting. When and how to overrule your phone’s automation.

Part 3: Hand. How to create the image you want. Quick fixes for common SNAFUs. Good old brightness and contrast. Color correction.

These parts are joined by their entourage of functionaries, by which I mean helpful but skippable supplemental sections about recommended software (including free options), fine points of image editing, and technological nerdery.

Part 1: Mind

Let us begin with a square look at the job we aim to do. What is the essence of it?

Photography is the art of capturing and reproducing an image.

Notice this is and always has been a dual endeavor. It is actually two simpler jobs. The photographer records light, then creates an image of it. To do these tasks well, we will need to understand the principles at work.

Capturing an Image

I’m sure you already know the fundamentals. Light cast from some source bounces off the subject toward the camera, which focuses the image and records it.

Even this simple explanation has something to teach us. The process doesn’t start with the subject, camera, or artist. The necessary material is a grip of photons in a pleasing arrangement.

Every photo begins with light. Painters, composers, and writers can start with a blank page; Photographers are like sculptors whose media are stone, driftwood, or found objects. Be aware of the illumination you have to work with.

Having found a happy confluence of light rays, you snap a pic. How does the camera capture the image?

What Exactly Is Going On In There, or How Cameras Work

Heads up, we’re gonna cover a lot of ground here. But don’t worry! There will be no quiz, and you don’t have to absorb it all. Breathe easy. You just need to get the gist and learn a few new terms.

camera diagram

The light passes through the aperture, which limits the rate photons are admitted; through the lens, which focuses the image; and onto the sensor, which converts photons into electric charges. When the user takes a picture, the sensor’s circuitry converts the intensity of charge collected by each pixel into numerical data. Then software interprets the info and creates a digital image file.

This vocabulary is important, so I’ll go into a bit more detail, especially where mobile phones are concerned.


This is an assembly of shades around the lens. An adjustable aperture expands or contracts to change how much light enters the camera at once. Apertures are measured in f-stops, a densely technical holdover from film cameras.

Luckily, almost all smartphone cameras have fixed apertures. We don’t have to fuss with it (or wrap our heads around f-stops, hooray!). On the downside, we can’t change the aperture to control the rate of light coming in. It depends entirely on the amount of light in the scene. This is especially troublesome in dim illumination, because we can’t widen the aperture to catch more photons; the aperture is already as wide as it can be.


Lenses for smartphones need to be compact and durable, so they’re mostly solid-state, meaning their primary lens elements can’t move. Therefore they are incapable of optical zoom (as opposed to digital zoom, which is garbage). We can’t adjust lens configuration to make the subject larger or smaller in the picture. To do that we have to move the camera closer or farther.


These circuits comprise millions of photosensitive diodes arranged in a grid. Each diode represents one pixel of the image. When the camera captures a photo, each pixel of the sensor reports the charge it collected, and each charge is converted to a numerical value. The circuit collates and interprets those pixel values. For our purposes, it’s important to note that the overall brightness of the image is an adjustable part of that interpretation. We can instruct the sensor to parse the scene as darker or lighter.

Shutter Speed

This tells how long the sensor was exposed to light. Exposure duration, length of exposure, fast/slow or short/long exposure, and shutter speed are different terms for the same thing. The duration of exposure affects how much light is captured by each pixel (i.e., how many photons it collects). Shutter speed is expressed in seconds, usually small fractions. One thirty-third of a second (1/33 s), one tenth of a second (1/10 s), one fifth (1/5 s).

Phone cameras don’t have actual shutters. Unlike film and high-end digital cameras, smartphones don’t need to physically open and close the sensor chamber, but they must be told when and for how long to record image data. Which amounts to the same thing.


Exposure refers to all relevant settings taken together. A good exposure means usable data was captured with the specified aperture, lens configuration, photosensitivity, and duration. A bad exposure means one or more of those elements was misadjusted, and the image info is not fit for purpose. More specifically, a good exposure shows the desired level of detail on the main subject and reproduces the image’s colors well.

Note that four elements affect exposure, but smartphones can adjust only two. Apertures and lenses are are out of our hands, but we can vary photosensitivity and shutter speed to our hearts’ content. Much more on that in Part 2.


Everything visible in the image is said to be “in frame.” Anything in the real place that does not appear in the image is “out of frame.” Don’t discount the power of framing! A different point of view can completely transform the picture’s effect.

Good Shot

Good/useful/effective shot/capture/data/exposure. These various terms mean the same thing. When both the exposure and framing are satisfactory, that’s a good capture. As we’ll see in Part 3, both factors can be adjusted somewhat in post-production, as long as the image contains the requisite data. With experience, you’ll develop a feeling for when your shots are fit, or at least in the right ballpark.

Technological Nerdery

This is a vastly simplified account of how your camera works. There’s not one lens, but several lens elements that perform different functions like preventing glare and correcting color drift. The aperture is built into the lens assembly.

The sensor determines color by means of a Bayer filter, which causes only red, green, or blue light to strike each pixel. The circuit and software interpolate the values of each pixel’s other two channels, using some of the coolest applied math ever devised by human minds.

Why do some new phones have two big cameras? The short answer is because the phones are so slim: a telescoping lens would be too fragile, and there’s not enough depth to add more than one lens assembly in front of the sensor. Adding an entire second camera makes the phone more expensive but no thicker and gives it the choice of two lens types (usually wide angle and 2x telephoto).



Reproducing the Image

Just as capturing the image involves both technical factors and subjective decisions, so does reproducing it. Printing a picture and creating a digital image file involve choices of color interpretation, size, format, and sometimes medium.

Hardware and software in your phone make those decisions near-instantly, producing a machine-interpreted version of the image. That’s good enough most of the time, which is frankly amazing. The machine can’t recognize what’s in the picture or fathom what it means, yet the vast majority of the time it creates an intelligible photo. As effective as the algorithms’ shortcuts are, there’s no substitute for true understanding. There will always be times when you know better.

Recognize the trade-off here. The more you delegate to the camera’s automation, the faster you can create photos, at the cost of less control. Making more decisions yourself gives you greater control, at the cost of taking more time.

Photosensor chip

Digital Images

Smartphones store photographs as digital image files. Each file is a long list of numerical color values for every pixel in the picture, with an introductory key that tells how the information is encoded. It’s paint-by-numbers for computers.

As we’re all hep to the Internet, we know digital photos can be easily, prodigiously, irresponsibly copied. It takes only a few tippy-taps to reproduce an image perfectly. So we got that going for us, which is nice.

Better yet, our pocket computers are powerful enough to modify photos. If the picture is just a collection of numerical data, changing the numbers will change the picture. Digital images are amazingly malleable and versatile.

We possess a great power, long dreamed of by analog photographers, not only to interpret but to transform photos. There’s a reason “Photoshop” became a verb: this is something new. No longer limited to mere reproduction, now we can recreate the picture in our mind’s eye when we snapped the shot. That’s what Part 3 is about.

crossroads with tree

We Are at a Crossroads, Like Way Out in a Desert Maybe

For the first time there is a single tool competent at photography’s two jobs. Smartphones both capture and reproduce images with great fidelity. Plus they can automate much of the work, significantly alter the photos, and they’re easily portable.

Someone should snap a pic of this cool-looking spot. Who has a camera? Everyone.

Appendix A: Recommended Software

Free Camera Apps

Android: Open Camera, Google Camera, A Better Camera, Camera MX, and VSCO Cam. There are several good options for Google’s operating system, whose users are more accustomed to getting things free.

iPhone: VSCO Cam or the built-in iOS Camera app. Apple’s software is fairly capable, so there’s not much need for a free replacement.

Paid Camera Apps

Android: Camera FV-5, Camera Zoom FX, Manual Camera. These apps have sterling reputations.

iPhone: Camera+, Halide, ProCam 6, ProCamera. These are just a few of the best choices for Apple devices.

Free Photo Editors

My vote for best free editor is Snapseed. It has a clean interface, and it doesn’t browbeat users to buy add-ons. Other good choices are Photoshop Express, PolarrDarkroom, Pixlr, VSCO Cam, and Aviary.

For general-purpose editing, these apps have both platforms covered. Be advised that some require creating a free account, and to various degrees they’ll try to get you to use their cloud storage or social media, or entice you to pay for filters and premium features.

Instagram‘s editor is satisfactory if a photo needs just a couple tweaks before sharing.

Facetune fixes problems common to portraits, selfies, and pet pics. The free version is limited and naggy, though.

Paid Photo Editors

Afterlight is my favorite. It costs $3.

Lightroom CC is the best choice if you already have an Adobe Creative Cloud account. (I believe the cheapest tier is ten dollars per month.)

Facetune‘s premium tools can do astounding things to pictures of people, such as reshaping and resizing their features, clearing skin tone, and changing eye colors. If portraits are your jam, it might be worthwhile to upgrade to “VIP.” For me it’s too expensive: $6/month, $36/year, or $70/forever.

If you like one of the free editors, an add-on feature or two might cover everything you need.



continue to Part 2 >