You’ve probably seen those cinematic clips of a dog catching a frisbee in mid-air or a champagne cork popping in glorious, buttery-smooth detail. It looks professional. It looks expensive. But honestly, you’re holding the only tool you need to recreate that exact vibe in your pocket right now.
Most people think they know how to do slow motion on iphone just by swiping to the "Slo-mo" tab in the camera app and hitting the big red button. While that gets the job done, there is a massive difference between a grainy, flickering mess and a crisp, high-end sequence that looks like it belongs in a Netflix documentary.
The Secret Sauce: 120 vs. 240 FPS
When you open your camera, you aren't just taking a video; you're capturing a specific number of frames every second. This is what experts call "Frame Rate" or FPS.
If you go into Settings > Camera > Record Slo-mo, you’ll usually see two choices. 1080p at 120 fps or 1080p at 240 fps. On the newer iPhone 16 Pro and 17 Pro models, you can even jump up to 4K at 120 fps.
Here is the trade-off nobody tells you about.
The 240 fps setting makes things much slower. It’s great for super-fast action like a humming bird's wings. But because the camera has to take 240 pictures in a single second, it can’t let in much light. If you try to film 240 fps indoors under regular lightbulbs, your video will probably look dark and grainy. Even worse, it might start flickering like a broken neon sign.
120 fps is the "sweet spot" for most people. It's half the speed of real life (or a quarter, depending on your playback settings), it stays sharp, and it handles lower light way better than the 240 setting ever will.
How to Shoot It Right
First, open that Camera app. Swipe past Photo, past Video, and land on Slo-mo.
Before you start recording, look at the top right corner. You’ll see the resolution and the frame rate listed there. On many newer iPhones, you can actually tap those numbers to change them on the fly without digging through your system settings. It's a lifesaver.
- Find the Light. Slow motion craves light. If you're indoors, move near a window. Outside? The sun is your best friend.
- Lock Your Focus. Tap and hold on your subject until you see "AE/AF LOCK" in yellow. This prevents the camera from "hunting" for focus while the action is happening.
- The Buffer Trick. Start recording about two seconds before the action happens. Don't wait for the jump or the splash. Give yourself some "runway" to edit later.
Why Is My Video Flickering?
This is the number one complaint. You’re trying to figure out how to do slow motion on iphone in your kitchen, and the screen looks like a strobe light is going off.
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It’s not your phone. It’s physics.
Most indoor lights—especially LEDs and flourescents—actually pulse at 60Hz. To our eyes, they look steady. But when you’re filming at 120 or 240 frames per second, your camera is literally "seeing" the gaps between the pulses of light.
To fix this, turn off the overhead lights and use natural sunlight. If you have to be indoors, move to 120 fps instead of 240. It won't totally fix it, but it'll be less distracting.
Editing the "Slow" Part
The coolest thing about the iPhone's native slow-mo is that it doesn't bake the speed in forever. When you record a Slo-mo clip, the phone records the whole thing at a high frame rate but only "plays back" a specific section in slow motion.
Go to your Photos app and find your clip. Tap Edit.
Under the video timeline, you’ll see a row of vertical white lines.
- Where the lines are close together, the video plays at normal speed.
- Where the lines are far apart, the video is in slow motion.
You can slide those two tall bars to choose exactly when the "epic" part starts and ends. Honestly, keeping the beginning and end at normal speed makes the middle part feel way more dramatic. It’s a classic filmmaking technique called "speed ramping."
What if I want to turn a normal video into slow motion?
You can’t really do this perfectly inside the default Photos app because a regular video only captures 30 or 60 frames per second. If you try to slow that down, it looks "choppy" because there aren't enough frames to fill the gaps.
However, if you have a Pro model, you can shoot in 4K 60 fps and then use an app like iMovie or LumaFusion to slow it down to 50% speed. Since 30 fps is the standard for smooth video, cutting 60 fps in half still looks great. It’s a "hack" for when you forgot to switch modes.
Pro Tips for 2026 Users
If you're using the iPhone 16 or 17 Pro, you have the Camera Control button on the side. You can actually use that to slide through your zoom levels while in Slo-mo mode. Just be careful—zooming in reduces the amount of light reaching the sensor, which makes that "grainy" problem even worse.
Also, check out Audio Mix. If you’re on iOS 18 or later, you can tap Edit > Audio Mix and choose "Cinematic" or "Studio." This helps isolate the sound of the person in the video while dampening the background noise, which often sounds like a weird, low-pitched rumble when slowed down.
Wrapping It Up
Mastering how to do slow motion on iphone really comes down to three things: lighting, choosing the right FPS for the scene, and nailing the edit in the Photos app.
Stop using 240 fps for everything. It's overkill for a person walking or a slow wave. Save the high frame rates for the truly chaotic moments, and stick to 120 fps for that professional, cinematic look.
Next Steps:
- Open your Settings > Camera > Record Slo-mo and ensure you're set to 1080p at 120 fps for the best all-around quality.
- Head outside during the "Golden Hour" (an hour before sunset) and practice a speed-ramp edit on a simple subject like a moving car or a running pet.
- If you're seeing flicker indoors, immediately drop your frame rate or move to a window to save the shot.