How the iPhone Duo's camera is different from the iPhone 18 Pro's

The two still have plenty of overlap. Both support 24MP and 48MP photos, adjustable portraits and updated Photographic Styles, including texture and grain adjustments. They can each record in 4K Dolby Vision at up to 120 fps, and both let you apply Cinematic effects after the fact.

But the Pro's advantages become clearer when you want to take over from the phone's automatic settings. Thanks to the new variable aperture, the Pro offers, well, Pro Controls, which are manual adjustments for things like shutter speed, white balance and aperture. The Duo doesn't offer that.

The Duo also lacks ProRAW photos, which preserve extra sensor data for advanced editing in apps like Lightroom. Video gets shorted, too: there's no ProRes, ProRes RAW or Apple Log 2 for more flexibility in post-production. Of course, those features will be missed by those who are into fine-tuning professional-class shots with professional-class tools. But if your photography doesn't go much farther than selfies and capturing the dog doing something funny? Well, you probably won't miss them.

Other features are also MIA. The iPhone 18 Pro has second-generation sensor-shift stabilization (the Duo uses the older version), an Adaptive True Tone flash (the Duo's isn't adaptive) and a studio-quality four-microphone array. The Duo also can't record spatial photos or videos, and it lacks Apple's new Reference Image feature, which captures signed sensor data alongside the photo to verify what the camera originally saw.

So, the iPhone 18 Pro is better if you want to shoot distant subjects, more advanced manual control or edits or the more all-around capable camera system. 

With cameras that are a step down in several ways, the Duo isn't simply an iPhone 18 Pro that folds. For $2,000 and up, that might be a hard pill to swallow. If you're forking that over, it's probably because you like the folding design and have disposable income. But hey, as a bonus, at least it's also easier to prop up, join the group shot and let everyone check their framing.