Evios: Light Meter for Film

Evios is a reflected-light meter for film and manual cameras. Point your iPhone at the scene, read the exposure, set your camera.

METER
• Live metering from the iPhone camera, normalized to EV100
• Tap the viewfinder to spot meter one area, or use the whole-frame average
• HOLD freezes the reading while you lower the phone and set your camera
• Manual EV mode with scene presets for planning without the camera

SET WHAT YOU WANT
• Aperture priority or shutter priority: fix one, Evios gives you the other
• Full, half or third stops, to match the clicks on your camera
• Readings between two marks show the difference, like +⅓
• Exposure compensation in thirds, from −3 to +3

YOUR FILM
• 33 film stocks from Ilford, Kentmere, Kodak, Fujifilm, CineStill, Foma and Lomography
• Pick a film for its box speed, then push or pull with the ISO dial
• Long exposures are corrected with the manufacturer's published reciprocity data (Ilford and Kentmere, Kodak Tri-X and T-Max, Fujifilm Provia). For other films, Evios tells you when you're past the published range
• Exposures longer than 30 seconds are shown as Bulb times

YOUR CAMERA
• Set your fastest shutter speed and your lens's aperture range; the dials only offer what your gear can do
• Clear warnings when a scene needs more than your camera or lens can give, and what to change
• A one-time meter calibration, checked against a reference meter or Sunny 16

HONEST ABOUT ACCURACY
Evios works out exposure from the settings the iPhone camera is actually using, corrected for how far the frame is from its exposure target. Very dark scenes can be beyond what the phone can measure; Evios tells you when that happens.

PRIVACY
The camera is used only to measure light. No photos or videos are captured, stored or sent. No account, no tracking.