NaturalCam/Tutorials
How this camera is built
NaturalCam is a small app with an unusual number of decisions in it. These are the ones worth writing down — real code from the app, and the reasoning that produced it, rather than a tour of an API that already has documentation.
The series
One idea, one article.
A long exposure on iOS, built from one-second frames
iOS caps any third-party app's exposure at one second, on every iPhone. Summing frames in linear light for a longer exposure, averaging them for a quieter one, and the streaming accumulator that stacks 32 RAWs without ever holding more than one in memory.
Tutorial 03 · System integrationGet your camera app into iOS's Camera Control list
A Locked Camera Capture extension is necessary and not
sufficient. What CameraCaptureIntent actually
does, why the intent must be compiled into three targets or
fail silently, how to reach an extension that shares no
storage with your app — and the entitlement that does not
exist, which costs people a day.
How to build a circular slider in SwiftUI
The arcs that carry shutter speed, ISO and focal length, built from nothing in ten steps: rung-to-angle maths, why dragging is absolute rather than accumulated, hit testing an annulus so the shutter button keeps its own touches, the left-handed mirror, and detent haptics. With the control running in the page and the whole file to download.
Tutorial 02 · RAWRAW vs JPEG on iPhone: what RAW actually buys you
Bayer RAW vs Apple ProRAW — a distinction Apple's own naming obscures — what the extra bit depth and re-developability are actually for, why JPEG and HEIF are still the right call most of the time, and why NaturalCam bakes that choice into its modes instead of a settings toggle.
More, as they are written
The queue is the rest of the interesting parts: the develop pipeline itself — demosaic and colour rendering with Apple's processing switched off — and the film-look LUTs. Nothing is listed here until it exists.
Why these exist
Written from the source, not around it.
Every listing in these articles is code that ships in the app, or a distilled version of it that compiles on its own. Where a number looks arbitrary — 110 degrees of sweep, 141 points of reach, a scale floor of 0.62 — the article says where it came from, because that is the part you cannot get from a screenshot.
They are also honest about the failures. The label-placement algorithm is greedy because the arithmetic one printed 105 and 135 on top of a native 100, and that is in the article rather than quietly fixed.
The app
One frame, no processing.
NaturalCam takes one Bayer RAW frame from one locked physical lens and develops it with Apple's processing switched off — no Smart HDR, no Deep Fusion, no sharpening, no noise reduction. The controls these articles describe are how you drive it.