Locking Exposure and Then Leaving It Alone
Last lesson we worked out what exposure actually means — the amount of light your photo lets in — and how your phone makes a fresh guess about it every time you point it at something. Today you're going to take control of that guess and pin it in place.
The thing about that guess is your phone re-checks it constantly. Move the phone an inch, it re-guesses. Something walks through the background, it re-guesses. When you're trying to hold a shot steady — especially with a bright window behind or a dark corner in front — that constant re-guessing is exactly what wrecks the picture. The exposure keeps sliding around underneath you.
So you lock it. Then you leave it alone. That second part is the hard part, and I won't pretend otherwise.
How to actually do it
Tap your screen where you want the exposure to read from, same as you did with focus a couple lessons back. On most phones a little box or circle appears, and next to it, a small sun icon with a slider.
Now the new step. Press and hold that same spot for a second or two. You'll feel or see something shift — usually a little "AE/AF LOCK" banner at the top of the screen. That's it. You've locked it. Exposure and focus are both pinned to that spot now, and moving the phone won't undo them.
If you want to adjust the brightness after that, drag your finger up or down on that sun-icon slider before you shoot. Up brightens, down darkens. Do it once, then stop touching it.
Try it on something easy to start. Sit at your kitchen table, tap on a coffee mug, lock it, then slowly move your phone left and right. Watch the rest of the frame get brighter or darker as you move — while that mug stays exactly as bright as when you locked it. That's the whole trick.
Where this actually matters
You'll feel this most with backlit stuff — somebody standing near a window, a kid on the porch with bright sky behind them. Without the lock, your phone keeps trying to expose for that bright sky and your kid turns into a shadow. Lock the exposure on their face, and the sky can do whatever it wants. Your kid stays a person instead of a silhouette.
It also matters for anything you're photographing more than once in the same light. Say you're doing progress shots of a project — same table, same window, over a few days. Lock the exposure once you've got it looking right, and you'll get consistency shot to shot instead of your phone re-guessing every time and handing you five slightly different versions of the same light.
The part where I admit I was bad at this
The first time I used exposure lock, I didn't trust it. I'd lock it, then second-guess myself and tap again to "check" — which of course unlocks it and starts the guessing all over. I did this trying to shoot the sunset over the point of the mountain, kept fiddling with it, and by the time I quit messing around the light had changed and the shot was gone. Dang.
Now I lock it and physically make myself not touch the screen again until I've taken the photo. One problem at a time. If it looks wrong after you lock it, that's fine — just tap somewhere else and re-lock. But don't lock it and then poke at it. That's the discipline part, and it took me a while to actually believe the lock was working instead of second-guessing my own phone. You'll get there faster than I did.
Where I land on this, plainly: it's one of those tools people skip because it feels like an extra step, and it's the extra step that actually gets you the shot. I'd rather take three extra seconds to lock it than take ten photos hoping one comes out.
A quick note on quilts, because you knew I'd get there
I locked exposure on a progress photo of Edwin's quilt a while back — nothing fancy, I just wanted the fabric to read true instead of getting washed out by the window behind it. Sent it to my sister the way I send her everything. She asked what pattern it was. Then she asked for the shop. We were on the phone for twenty minutes about fabric. That's the kind of thing that happens when the photo actually shows the thing instead of fighting the light. I won't pretend that conversation wasn't the best part of my week — because I live for that, and I'm not going to act like I don't.
Before next time
Find one backlit spot in your house — a window with something in front of it — and practice locking exposure on the subject instead of letting the window win. See what your kid, your dog, or your dinner actually looks like, instead of a shadow with edges.