Did you hear how many times Apple said “optical-quality” at its iPhone 17, 17 Pro, and Air launch event? I lost count. This new buzzword seems to be confusing a lot of people, though. What exactly is “optical-quality,” and is it any different from digital zoom?
What Does Apple Mean When It Says “Optical-Quality” Zoom?
Apple focused heavily on their Fusion Camera systems for the new iPhones, specifically singling out the optical-quality zoom that’s now a part of the entire iPhone lineup. What does optical-quality mean though?
Apple is using this buzzword in order to avoid saying what they’re actually doing: cropping. You see, the main sensors for the entire iPhone 17 lineup is 48MP. This is a pretty high-resolution sensor, and Apple is simply cropping into that sensor to make something look more zoomed in.
While you’ll normally capture a 24MP or 48MP photo, when using the optical-quality zoom, it crops down to 12MP. Because 12MP is still pretty high-resolution, this achieves a quality similar to optically zooming, but it’s nowhere near the same thing as taking a 48MP picture with proper optical zooming.
The iPhone Air Doesn’t Actually Have Multiple Cameras
Apple billed the iPhone Air as having “two advanced cameras in one,” leading many to think that it had multiple cameras. The problem is, there’s just one single 48MP camera on the back of the iPhone Air.
With the iPhone Air, what Apple is doing is capturing 1x photos at 24MP or 48MP, and 2x photos at 12MP. There’s some AI magic happening in the background, but at the end of the day, it’s just taking a cropped photo and calling it “optical-quality zoom.”
So It’s Just Sensor Cropping?
In short, Apple is just cropping in on the sensor to take a more zoomed-in image. In reality, it’s a bit more complicated than that.
Take the iPhone 17 Pro, for instance. With three physical lenses on the back, Apple says that it’s like having “eight pro lenses” in your pocket. This comes down to Apple utilizing these three sensors in very unique ways.
There’s a macro lens (which is using a combination of the ultra-wide and wide lenses), 0.5X (the ultra-wide lens), 1X, 1.2X, 1.5X, and 2X (which all use the wide lens), 4X, and 8X (which use the telephoto lens).
The only native lenses listed here are the 0.5X, 1X, and 4X options (13mm, 24mm, and 100mm full-frame equivalent focal lengths). All of the other options are a means of cropping into the sensor by however much is needed to achieve the desired zoom.
In reality, it’s no different than taking a picture and zooming in on it after the fact. Apple’s “optical-quality zoom” is nothing more than digital zoom wrapped in a more palatable package.
I don’t want to completely downplay the experience, however. Apple is providing a compelling experience with this digital zoom. In many instances, it can be relatively close to the effect of properly zooming with real optics—but there’s just no getting around the fact that this isn’t optical zoom at all, and it’s simply cropping in on the sensor.
Apple Is Using AI to Make the Image Sharper
In the background of every sensor-cropped—sorry, “optical-quality zoomed”—image there’s a lot of AI magic going on. Apple is using its on-device AI to demosaic the zoomed image and make it sharper. It’s essentially using the best area of the sensor to take the image, and then applying AI sharpening to help make it a bit clearer.
This definitely gives a solid result, but it’s just not the same as properly zooming. I’ve been a hobby photographer for well over a decade, and I’ve applied very similar denoising and sharpening techniques on my own photos that I zoom in on in post-processing. It’s a great way to save an image that otherwise couldn’t have been captured, but it’s still not a great solution.
Is Sensor Cropping the Same as Optical Zoom?
No, sensor cropping is not the same as optical zoom—but it’s not all bad, either. While it’s effectively digital zoom, 12MP photos can still print out pretty large. A 12MP photo can be printed at 14 x 20 inches at 300 DPI. This is much bigger than most will ever print, especially at home.
While a 48MP image is four times larger than a 12MP one, the smaller size is still plenty big. A 12MP image is 4000 x 3000 pixels at a 4:3 ratio. Compare that to your TV, which is only 3840 x 2160 pixels, and 12MP offers a higher resolution than every 4K TV on the market.
So, while a 12MP zoomed in photo isn’t “optically the same” as a 48MP photo at the same focal length, it’s still fine in most scenarios.
I get why Apple is saying that the different zoom ranges are “optical-quality,” but I really wish they’d dial back the marketing. Digital zoom will never offer the same quality as properly zooming with optics. Physics prevents this. But, in most scenarios, digitally zooming will be just fine for the majority of people.
