HOW TO PHOTOGRAPH

Light, and what you do to it.

Everything below works on any camera — a DSLR, a mirrorless body, a thirty-year-old film SLR, a disposable, a phone. The physics has not changed since 1826 and it is not going to. Where something only applies to a phone, it is marked phone. Where it only applies to a specific iPhone, it says so. The last section covers the iPhone 18 Pro, which just did something genuinely new and is worth its own chapter.

01The vocabulary, pronounced

The handful you will hear constantly. Nobody will tell you how to say them, and half of them are French.

Aperture AP-er-chur

The size of the hole the light comes through. Written as f-numbers.

f-stop

One step of aperture — f/2.8, f/4, and so on. One "stop" means double or half the light, and you will hear the word stop used for shutter and ISO too. It is the universal unit of brightness.

Shutter speed

How long the sensor is exposed. 1/250 means one two-hundred-fiftieth of a second.

ISO say the letters — eye-ess-oh

How strongly the camera amplifies what the sensor collected. Higher is brighter and grainier.

Exposure

Overall brightness — the result of the three above working together.

Depth of field

How much of the scene, front to back, is acceptably sharp.

Bokeh BOH-kay

Japanese, boke, roughly "blur". Not how much background blur there is — that is depth of field — but the quality of it. Whether out-of-focus highlights are creamy discs or nervous jittery rings.

White balance

Correcting for the colour of the light so that white things look white.

Histogram HIS-toh-gram

A graph of how many pixels are dark, mid, and bright. It tells you things your eyes cannot on a sunlit screen.

RAW

The unprocessed sensor file. Bigger, uglier straight out of camera, and far more forgiving when you edit. Not an acronym — it is just the word "raw", shouted.

Composition

How you arrange what is in the frame. "Rule of thirds" is the first thing anyone will tell you and the first thing you should outgrow.

02Light is the actual subject

Before any setting matters: a photograph is a recording of light. Not of a person, a mountain, or a drink on a bar. Of the light bouncing off a person, a mountain, or a drink on a bar. Change the light and you have changed the photograph completely, without touching the camera.

Three things about light decide almost everything:

• Direction. Light from the front flattens. Light from the side carves out texture and shape. Light from behind makes a silhouette or a halo. Move yourself ninety degrees and see what happens — this single habit will improve your pictures more than any purchase.
• Quality — hard or soft. A small light source relative to your subject (midday sun, a bare bulb, a phone flash) makes hard-edged black shadows. A large one (an overcast sky, a window with a curtain, a big bounced light) wraps around and softens. Cloud is not bad light. Cloud is the biggest softbox available.
• Colour. Light is rarely white. Candlelight is deep orange, midday is blue-white, shade is bluer still, old street lamps are sodium yellow. See white balance.

03The exposure triangle

Three controls decide how bright the picture is, and each one costs you something else. That trade is the entire craft.

They are measured in the same unit — stops. One stop is a doubling or a halving of light. That means they trade cleanly against each other: open the aperture one stop and you can halve the shutter time, and the brightness comes out identical. Only the look changes. That is the whole game.

04Aperture and f-stops

Inside most lenses is a ring of overlapping blades that opens and closes like an iris. That hole is the aperture.

Why the numbers run backwards

This confuses everyone, and it should, because it looks wrong. f/2 is a big opening. f/16 is a tiny one.

The reason: the f-number is a ratio, not a size. It is the focal length divided by the diameter of the opening. On a 50mm lens, f/2 means the hole is 25mm across — 50 ÷ 2. And f/16 means it is about 3mm across — 50 ÷ 16. It is a fraction, so the bigger the bottom number, the smaller the result. Once you see it as one sixteenth rather than sixteen, it stops fighting you.

The payoff of the ratio is that it is universal: f/8 lets in the same amount of light on any lens on any camera, which is why the scale survived.

The full-stop scale

Each step below halves the light of the one before it. The odd-looking numbers are because area scales with the square of the diameter, so the sequence multiplies by roughly 1.4 — the square root of two.

What to actually use

• f/1.4–f/2.8 — one person, background dissolved. Low light. Be careful: wide open, the sharp zone can be thinner than a face, and you will miss focus.
• f/4–f/5.6 — two or three people, or a subject with some depth.
• f/8–f/11 — landscapes, groups, architecture. Most lenses are also at their sharpest here, a couple of stops down from wide open.
• f/16 and beyond — rarely worth it. Diffraction starts softening the whole frame, so you buy depth of field with overall sharpness.

05Shutter speed

How long the sensor is allowed to collect light. Written as a fraction of a second: 1/1000 is very brief, 1/30 is comparatively ages, and anything with a " after it — 2" — is whole seconds.

The reciprocal rule

The old guideline for handholding: your shutter speed should be at least 1 divided by your focal length. On a 50mm lens, do not go below 1/50. On a 200mm lens, do not go below 1/200 — long lenses magnify your own shake along with the subject. Image stabilisation buys you several stops past this, but the rule is still the right instinct.

06ISO

ISO is how hard the camera amplifies the signal off the sensor. ISO 100 is no real amplification and the cleanest possible file. ISO 6400 is a lot, and it brings noise with it — speckle in the shadows, colour blotches, and a general loss of fine detail.

The scale doubles: 100, 200, 400, 800, 1600, 3200, 6400. Each step is one stop.

How to think about it

ISO is not a creative control. It is the one you raise after the other two have run out of room. The order that serves most people: set the aperture for the look you want, set the shutter fast enough to be sharp, then raise ISO until the exposure is correct.

And do not be precious about it. A noisy sharp photograph beats a clean blurry one every single time. Noise is a texture; blur is a missing picture. Modern sensors and modern noise reduction are extremely good, and nobody has ever looked at a photograph of something they love and complained about grain.

07Depth of field and bokeh

Depth of field is how deep the sharp zone is. Four things control it:

1. Aperture. Wider (lower f-number) = shallower.
2. Distance to subject. Closer = shallower. This is the strongest lever you have and the one people forget.
3. Focal length. Longer lenses compress and appear to give shallower depth.
4. Sensor size. Bigger sensors give shallower depth at the same framing. This is the real reason a full-frame camera "looks different" from a phone.

Note what is not on that list: the background being far away. That does not change depth of field — but it does change how blurred the background looks, because things further outside the sharp zone blur more. Moving your subject away from the wall is free and works on any camera, including a phone.

Bokeh is a quality, not a quantity

Bokeh describes the character of the out-of-focus area. Pleasant bokeh renders out-of-focus points of light as smooth, evenly-filled discs that melt into each other. Harsh bokeh gives them bright rims and hard edges — "onion rings" — which the eye reads as busy and nervous. It is a property of the lens design: the number and shape of the aperture blades, and how the lens corrects aberrations. It is why people pay strange amounts of money for particular old lenses.

08Focal length

Measured in millimetres. It decides how much of the world fits in the frame and how the space inside it feels.

Focal length does not distort faces — distance does. A wide lens makes you stand close, and standing close is what enlarges a nose. Shoot the same face from the same spot with any lens and crop to match, and the proportions are identical. The reason 85mm flatters is that it makes you stand back.

09Focus

• Single / one-shot autofocus — locks once. For anything still.
• Continuous autofocus — keeps tracking. For anything that moves.
• Manual focus — you turn the ring. Essential in the dark, through glass, or through foliage, where autofocus grabs the wrong thing.

Where you focus is a decision, not a formality. For anything with eyes, focus on the near eye. If the eyes are sharp the picture reads as sharp, even if very little else is. If the eyes are soft, nothing else can rescue it.

10White balance

Light has a colour, measured as a temperature in kelvin. Confusingly, low numbers are the warm ones.

White balance tells the camera what to treat as neutral. Auto is genuinely good now and is a fine default. The two places it fails: mixed lighting (a warm lamp and a cold window in one frame — something has to give), and scenes dominated by one colour, where it will try to "correct" a sunset into grey mush.

The fix for both is to shoot RAW, where white balance is a note attached to the file rather than a decision baked into it, and can be changed afterwards at no cost whatsoever.

11Metering and the histogram

The camera's meter measures the light and proposes an exposure. It does this by assuming the world averages out to a middle grey — which is usually true and occasionally very wrong. Photograph a snowfield and the meter darkens it to grey. Photograph a black cat and the meter brightens it to grey. That is what exposure compensation is for: the +/− control that says "I know better, make it brighter" or "darker".

Reading a histogram

The histogram is the one honest opinion available. Left edge is pure black, right edge is pure white, height is how many pixels are at that brightness.

• Piled against the right wall — highlights are clipped. That detail is gone and no editing recovers it. This is the one to avoid.
• Piled against the left wall — shadows crushed to black. Recoverable in RAW, up to a point, at the cost of noise.
• A narrow lump in the middle — flat and low contrast. Easy to fix later.

There is no "correct" histogram shape. A photograph of a black cat at night should be bunched left. The histogram tells you what the file contains, not whether the picture is good.

12RAW versus JPEG

Shoot RAW when the light is difficult, the moment matters, or you intend to edit. Shoot JPEG when you want to send it in ten seconds and the light is easy. Many cameras and phones will record both at once, which is the honest answer for most people.

13Composition

Everything above controls how the picture is recorded. Composition is the part that decides whether it is worth recording.

Rule of thirds — and why to move past it

Divide the frame in three, horizontally and vertically. Place things on the lines or their intersections. It works because it stops you centring everything, which is the beginner's reflex, and it leaves the subject somewhere to look.

It is a training wheel. Dead-centre is enormously powerful for symmetry and confrontation. The reason to learn the rule is so that breaking it becomes a choice rather than an accident.

The ones that actually carry the weight

• Leading lines. Roads, railings, shadows, a bar top. The eye follows lines. Point them at the subject.
• Framing. Shoot through a doorway, a window, branches. It creates depth and tells the viewer where to look.
• Negative space. Emptiness around a subject gives it room to be loud. The commonest mistake is cramming.
• Layers. Something near, something middle, something far. This is how a flat rectangle acquires depth.
• Get closer. The single most reliable improvement to a mediocre photograph. Almost every weak frame contains a strong one that needed you two steps nearer.
• Watch the edges and the background. Before pressing the button, run your eye around the border. Poles growing out of heads, a bright blob in the corner, a severed hand at the frame edge — all of it is fixable by moving six inches, and none of it is fixable afterwards.

14Actually taking the picture

A workable order of operations, on any camera that lets you set things:

1. Decide what the picture is about. If you cannot say it in a short sentence, the photograph will not say it either.
2. Find the light, then move. Section 2. This is the step people skip.
3. Choose the aperture for how much you want sharp.
4. Check the shutter is fast enough not to blur — the reciprocal rule as a floor.
5. Raise ISO until the exposure is right. Do not flinch.
6. Focus deliberately — the near eye, if there are eyes.
7. Scan the edges. Two seconds. It will save more frames than any setting.
8. Take more than one. Expressions change between frames. Film discipline is a romantic idea; memory cards are cheap.

15What a phone really does differently

phone

A phone is a real camera with a very small sensor and an enormous amount of computing bolted on. Both halves matter.

• The sensor is tiny, so it collects little light and depth of field is very deep. That is why nearly everything in a phone photograph is in focus, and why the blurred-background look has to be faked.
• Portrait mode is a depth map plus a blur filter. It is getting very good, but it guesses at edges — look at hair, glasses frames, and the gaps between fingers, which is where it gives itself away.
• Every photo is a composite. The phone shoots a burst before you press the button and merges frames for dynamic range and noise. This is why phone photos of high-contrast scenes often beat a real camera's single exposure — and why they sometimes look strangely flat and over-processed.
• Night mode is a stack of exposures aligned and merged. Hold still for the whole countdown; that is real exposure time, not a progress bar.
• HDR is applied by default and will happily flatten a moody scene you wanted dark.

What to do about it: use the main camera rather than the ultra-wide when you care; tap to set focus, then drag the exposure slider down a touch to protect highlights; shoot RAW if your phone offers it; clean the lens, which is genuinely the single most common cause of soft, hazy phone photographs; and get closer rather than zooming.

16The iPhone 18 Pro and its physical iris

This is the first time in this guide that a phone gets its own chapter, and it has earned it: after fifteen years of fixed openings, an iPhone has an actual moving aperture.

The 48MP main camera now contains a real iris — six laser-cut blades on a rotor mechanism, the same idea as the lens on a proper camera, shrunk to fit in a phone. It moves between four selectable apertures:

Be precise about what this is. It is not a continuous range — it is four discrete stops, chosen by you or by the phone. And it is not the software "aperture" slider that portrait modes have had for years. That one adjusts how much blur gets painted on afterwards. This one physically changes the size of the hole the light comes through, before the picture exists.

Why it genuinely matters

• Depth of field becomes real. Narrowing to f/4 actually keeps the back row of a group photograph sharp, rather than asking an algorithm to guess who should be blurry.
• Opening to f/1.48 collects real light — not amplified light. That means lower ISO and less noise at night, which no amount of processing gives you for free.
• Diffraction still applies. On a sensor this small, f/4 is already narrow enough that overall sharpness softens slightly. Use it for depth of field, not because "stopped down is sharper" — that rule comes from much larger sensors.
• It also ships with manual pro controls, which means the three sections above — aperture, shutter, ISO — are now directly usable on the phone in your pocket.

17Quick reference

The settings are a week's work to learn and a lifetime to stop thinking about. The light and where you stand are the whole job.