A medium-format film camera on a tripod in a granite valley at golden hour

GlassMeter · Yosemite Valley

Yosemite Photo Safari

Yosemite Photo Safari runs on a laptop or desktop — it draws the whole valley in 3D. Send yourself the link and open it there.

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Yosemite Valley

Yosemite Photo Safari

Pick a , shape the sky under , and open to meter and shoot.

Set the scene
Press METER
Press the shutter

18:36

sun 17°

Explore Camera Page

18:36

Portra 400

Drag to aim · click to spot-meter · double-click to focus

DoF — — EV —

About this page

A meterless camera, a real valley.

This camera was made in 1988 without a light meter: photographers carried one in their pocket. GlassMeter is that meter for your phone, with 30 films and the Zone System built in.

How to shoot

Aim: Drag inside the phone's viewfinder (or use the arrow keys) to frame your shot.
Spot-meter (optional): Click bright or dark areas in the viewfinder to pin their Zone from 0 (black) through V (mid-grey) to X (white).
Meter: Press METER (M) — the unlocked dial turns to the proper exposure. Click a dial's centre hub to lock it first.
Focus: Double-click your subject in the viewfinder, or drag the 3D focusing ring.
Shoot: Press the white shutter button (F). Your print develops in the tray at the bottom-left.

New to this camera? Camera School teaches the crank, dark slide, lenses and Zone System hands on.

Keyboard shortcuts

Meter & Shoot

Show / hide phoneG

Meter exposureM

Release shutterF

Next / prev lensL

Aperture f-stop[ ]

Shutter speed− =

Focus distance, .

Aim camera← ↑ ↓ →

Explore the Valley

Where to standB

Weather & cloudsC

Move tripodV

Landmark namesI

Watch the dayY

Wait for wildlifeO

Pause / time speedP T

Sound / share linkN K

3D Camera & Finder

Open / close hoodW

Look down into screenD

Flip 4.5× loupeZ

Preview depth of fieldX

Tripod head / explodeH E

Close active panelEsc

What's real (Physics, Light & Film)

The valley. Elevation from USGS 3DEP (1 m lidar around each viewpoint), colour and land cover from USDA NAIP aerial imagery, and the Merced from USGS hydrography. The sun, moon, stars and Milky Way follow their true astronomical paths for any date.
The light. Scene brightness is calibrated so a grey card in noon sun meters EV 15. The meter reads what the lens sees, just like the iOS app.
The film. Characteristic curves, grain, halation and filter responses are the app's own code, ported line for line.
The optics. Field of view, depth of field and aperture scales come from published Zeiss datasheets. The ground glass shows the lens wide open and mirror-reversed until stopped down.

Credits & data sources

Elevation: USGS 3DEP. Imagery: USDA NAIP. Hydrography: USGS NHD. Names: USGS GNIS (all public domain). Stars: Yale Bright Star Catalogue. Milky Way: NASA/Goddard Space Flight Center Scientific Visualization Studio, Deep Star Maps 2020; Gaia DR2: ESA/Gaia/DPAC (CC BY-SA 3.0 IGO). El Capitan's face: USGS ground-based lidar and imagery, May 4 2022 (Corbett, Collins & Helfrich; CC0). Half Dome, Bridalveil and Royal Arches: USGS 3DEP 2019 airborne lidar; Half Dome's colour from the photographer's own photographs. Fine rock detail on El Capitan's west face, Cathedral Rocks, Sentinel Rock, Royal Arches and the Yosemite Falls cliff: the site's own AI edits (Google Flow) of tree-free renders of this scene, projected back onto the lidar terrain through the renders' cameras. The Moon: NASA's Scientific Visualization Studio CGI Moon Kit (LRO LROC colour mosaic, public domain), placed by the IAU rotation model. Ground and bark textures: Poly Haven (CC0). The camera is modelled from the original service manual's drawings and the lens datasheets; it carries a Glass Works nameplate and is not affiliated with the original maker. Built with three.js.

Grinding the glass…

Building Yosemite from USGS lidar — about ten seconds the first time.