Studio C-41 · Photography Instrument

v1.0 · TestFlight Beta

POCKETMETER PRO

A light meter for photographers and cinematographers, built into the phone already in your pocket.

EV12.4
Shutter180° · 1/48
Apertureƒ/2.8
ISO400
ND0.6
Range6′ 4″
CrushedMiddle GraySkinClipped

One instrument

For stills and motion.

PocketMeter Pro reads the light straight off your iPhone's camera and hands you a working exposure the moment you lift it: shutter, aperture, ISO. Whether you shoot frames or footage, it talks in the numbers you already work in.

Live meteringTap to spotPriority locksLog & geotag

For Photographers

Nail the zone before you press the shutter.

Meter reflected light like a handheld classic. Tap a shadow to place it at middle gray, lock the two settings you care about, and read the third. It works in the f-stops and shutter speeds you already think in, with Kelvin white balance and geotagged frame logs.

Spot meteringFull-stop dialsND2–ND64Kelvin WB

For Cinematographers

Shutter angle, ND, and false color on set.

Switch to cinema mode for shutter angle and frame rate. 180° at 24 fps reads 1/48, with ND in density notation right on the deck. Flip on ARRI-style false color to judge exposure at the settings you dialed, and range your subject with LiDAR.

Shutter angleND 0.3–1.8False colorLiDAR range

On screen

Everything on one screen.

Live readout up top, the mode you're in, and the exposure deck. All of it sits over the viewfinder.

EV11.3
SPOT5200 K⌖ 4′2″
⚙
Shutter
1/125
Aperture
f/5.6
ISO
100
⇩ LOG
❚❚ HOLD
Meter

Read the light

Live EV, tap-to-spot, and your working exposure on the deck.

EV6.4
24 FPSND 0.67100 K
⚙
❈
Angle
180°
1/48
Iris
f/2.8
ISO
800
ND
ND 0.6
−2 stops
⇩ LOG
❚❚ HELD
Cinema

False color on set

Shutter angle, ND in stops, and false color at your exposure.

GEOTAGGED · SAVED TO PHOTOS
Saved to Photos
PocketMeter Pro — Jul 17, 2026 at 6:41 AM
EV 13.8  WB 5600 K  ⌖ 34′
T: 1/250  F: f/8  ISO: 100  ND8
Log

Geotagged records

Every reading stamped and saved to Photos, pinned to where you shot.

What it does

Every reading a real meter gives you, straight off the sensor.

Point, meter, and get a complete exposure the moment you lift the phone. Built for film shooters and cinematographers who think in stops, angles, and zones.

Meter

Live scene metering

Real-time exposure read straight off the camera sensor. You get EV plus a full shutter, aperture, and ISO reading that tracks the light as you move.

Priority

It gives you the stop

Lock the iris and ISO you're shooting and the shutter tracks the light. Lock just one and it picks a sensible pair for the rest. Whatever you leave open is the number it hands you.

Spot

Tap to spot-meter

Tap a shadow and it's placed at middle gray, spot-meter style. Tap back out to overall scene metering any time.

Dial

Scrub-wheel controls

Tap a value, drag to dial it in with haptic detents, release to set. The other dials move with it as you turn. It feels like a real meter, not a form.

Cine

Cinema mode

Shutter angle and frame rate instead of speed. 180° at 24 fps reads 1/48, with ND in density notation (0.3–1.8) right in the control bar where you dial.

False Color

Exposure map on the viewfinder

ARRI-style false color: green is middle gray, pink is skin, red clips. Bands read relative to your dialed settings, not the phone's auto-exposure.

Range

LiDAR rangefinder & Kelvin

Distance to your subject in feet and inches on Pro devices, plus a live scene color-temperature readout for matching white balance.

Log

Log, geotag & hold

Save an annotated frame to Photos with the full exposure stamped on it, geotagged to where you shot it. Hold to freeze a reading while you work.

Developer release notes

Build log

Version 1.0 Build 1 · iOS 17+ TestFlight Beta
  • MeteringReal-time metering via AVFoundation continuous auto-exposure; scene EV100 derived from ISO, shutter, and lens aperture with a user calibration trim.
  • SolverExposure solver covering zero-, one-, and two-lock cases over third-stop tables, with range clamping and over/under-exposure warnings.
  • SpotSpot metering via exposurePointOfInterest; center-weighted scene metering as the default, one tap to reset.
  • CinemaShutter-angle model across 23.976–60 fps; ND filters 1–6 stops with mode-aware labels — density (ND 0.6) in cinema, filter factor (ND4) in photo.
  • False ColorMetal + Core Image color-cube pipeline, offset by the solver's deviation so bands read relative to the dialed exposure rather than the phone's AE.
  • RangeLiDAR depth sampling — median of a 5×5 patch with hole rejection — for subject distance in feet/inches; auto-hidden on devices without LiDAR.
  • DataAuto-white-balance color-temperature readout in Kelvin.
  • CaptureLOG writes annotated, geotagged stills to Photos (add-only permission); HOLD freezes the current reading. False-color frames log as shown.
  • LayoutFull portrait and landscape support with translucent floating controls that keep the viewfinder clear.
  • IdentityBundle identifier set to com.studioc41.mylightmeter ahead of Studio C-41 distribution.

Next On-device EV calibration against a reference meter, then TestFlight external distribution.