Why does Apple think three lenses are eight lenses?

The super-thin iPhone Air only has one camera on its rear: a 48-megapixel sensor with a 26mm-equivalent f/1.6 lens. It’s the same as the main camera of the regular iPhone 17 (which also features a second 0.5x ultrawide camera). The 17 Pro and Pro Max have a similar-but-not-the-same main camera, consisting of a 48MP sensor and 24mm-equivalent f/1.78 lens — and it also has the ultrawide and adds a 4x telephoto lens.

So those are the phones and their cameras, but what about Apple’s complicated lens math?

Apple showed a slide of sample images indicating that the iPhone Air’s one rear sensor and lens can be used as 26mm, 28mm, 35mm, and 52mm-equivalent lenses. According to Apple’s technical specifications of the iPhone Air, once you zoom to the 52mm-equivalent focal length (a 2x magnification), you’re down to 12MP of resolution. The 28mm and 35mm “lenses” are likely similar to what we first saw in the iPhone 15 Pro, which works like this:

As for the iPhone 17 Pro, its three actual lenses are billed as equivalent to eight (up from the claimed seven of last year’s 16 Pro model). If its eight “pro lenses” start with the four of its main camera, like the Air’s, then its 48MP ultrawide and telephoto cameras make up the other four. noti.group reached out to Apple for clarification on this and to enumerate all these “pro lenses” in the iPhone 17 Pro and iPhone Air, but the company did not respond by the time of publication. So here’s my best estimation of how Apple got eight lenses from three:

So that’s how Apple’s lens math works across its cameras. Apple reps called these lenses “optical quality” during the company’s keynote presentation. But are these optical zooms? No, not really. Like most smartphones, they’re a mix of fixed focal length optics and clever computational photography. “Optical quality” is obviously a loose-fitting marketing term. But what’s even more strange and confusing is how Apple’s site lists lenses across its iPhone 17 line as “optical zoom options.”

If you want to get technical, none of these are optical zooms in the traditional sense. An actual optical zoom is a lens that changes focal length optically. Like when you turn a ring on the barrel of a lens or a toggle on a point-and-shoot and the lens physically moves, rendering a different field-of-view on the image plane. I know in the world of smartphones, we use “zoom” a bit loosely to mean any telephoto lens or cropping / digital zoom, but being this fast and loose in your marketing terms feels like it’s getting into misleading territory.

Apple is no stranger to being vague in its marketing to make it seem like you’re getting more of something — just try to read some of its charts from past videos and keynotes. But this lens count feels like pseudo-math designed to juice up a feature list and piss off camera nerds at the same time. Using actual optics for more focal lengths will always be better than one optic and some software, as my colleague Allison Johnson showed in her excellent shootout between the Google Pixel 10 Pro and all its AI gimmickry versus a Nikon camera with a bonkers optical zoom. (Yes, the Pixel fared well with correcting heat haze, but so would the Nikon when you bring it into post.)

The iPhone Air is not literally four lenses. But is it like having four lenses? Four “pro” lenses? How about four good lenses? We’ll have to find out.