Evios: Light Meter for Film
Spot Metering & Reciprocity
Only for iPhone
Free
iPhone
Spot meter with your iPhone, hold the reading, and get shutter speed or aperture for your film — with long exposures corrected using the maker's reciprocity data.
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.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
A big update to how Evios meters, and what it can do.
• More accurate readings: the meter now accounts for where the camera is in its exposure adjustment, settles quickly and no longer sticks on a stale value
• Spot metering: tap the viewfinder to meter one area
• HOLD the reading while you set your camera
• Aperture or shutter priority
• Full, half or third stops, with the difference shown between marks
• 33 film presets, with long exposures corrected using the maker's reciprocity data
• Camera and lens limits, with clear warnings when a scene is out of range
• Exposure compensation and a one-time meter calibration
• A new introduction and help sheet
The developer, Thor Morten Smerud, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Thor Morten Smerud
- Size
- 2.7 MB
- Category
- Photo & Video
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Thor Morten Smerud