LTP 109: Schrödinger’s Camera 1

Panel

• Bart Busschots (host) – @bbusschots – Flickr

In this solo show Bart gives his answer to a simple sounding but deceptively complex question from friend of the show Allison Sheridan — how many cameras does the iPhone 14 Pro have? Just two, one on each side? Or maybe four, three on the back and one on the front? But what about that new 2X mode using part of one sensor as what is effectively a different sensor? Is there a single right answer? Or is it Schrödinger’s Camera?

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Notes

Allison asked me a deceptively simple question recently — ‘how many cameras does the iPhone 14 pro have?’ — I started to say ‘well it obviously has …’ and I trailed off — it’s not obvious at all anymore!

I’ve been ponding this question for a few weeks now, and I’ve come to the conclusion that the answer depends on your point of view, and on your role in the iPhone photographic system’s development. In other words, I think the answer depends on which proverbial hat you’re wearing, and there are at least three hats!

Hat 1 — hardware (4 physical cameras)

Let’s start at the most basic level — what is a camera? It’s an optical system that focuses light onto some kind of light-sensitive surface that can record an image in some way (more on episode 41).

If lens + sensor = camera then the iPhone 14 pro has four cameras:

1. The front-facing camera.
2. The primary camera with its 48mpx sensor.
3. The 0.5x wide angle camera with a 12mpx sensor.
4. The 3x telephoto lens with another 12mpx sensor.

Hat 2 — Firmware (6 effective physical cameras)

With previous iPhones Pro you can skip this hat, but the iPhone 14 Pro has learned a new trick — the sensor in the primary camera operates in multiple modes, so you have to expand it from one to three:

1. Default mode — all 48mpx physical pixels are used to capture light, but they are grouped into fours (‘pixel binning’) so they act as a 12mpx sensor with way more light gathering power and way less noise.
>High resolution mode — all 48mpx pixels are used to produce a 48mpx image.
2. 2x Zoom mode — the centre 12mpx pixels are used to create a 2x physical zoom.

Hat 3 — Software & End Users (2 cameras)

Before we even get to the users, lets think about what the iOS camera app sees. The data recorded on those four physical sensors in their six possible modes doesn’t go into the camera app as six different data sources, it arrives as just two — the by-the-book front-facing camera, and the very smart main camera. Between the sensor and the camera app sits a very powerful image processing pipeline that straddles hardware, firmware and software, and combines data from all three sensors into a single image for the camera app to work with. In effect, the three physical cameras are combined into a single virtual camera that can smoothly zoom from 0.5 to 15x.

Maybe it’s Schrödinger’s Camera?

I think most iPhone users will genuinely feel they have just two cameras, one on each side of the phone, but I think things get a little more confusing for people like me (and probably many of you too). I choose to shoot in raw, and I choose to stick to the four ‘native’ zooms — 0.5, 1x, 2x, and 3x. To me the iPhone’s main camera is simultaneously one, three, and four cameras, and I collapse that superposition as and when it suits me!