f/oss vs Lume
Price, ratings, monetisation and update history for both apps, side by side ā with what reviewers say about each.
f/oss
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f/oss is a free light meter for film photography, rebuilt from the ground up as a fully native app. Point the spot-metering circle at your subject and read the exposure instantly. f/oss measures true photometric luminance through your iPhone's camera and is calibrated against professional reference meters. FIVE METERING MODES ⢠Aperture Priority: set f-stop and ISO, get your shutter speed ⢠Shutter Priority: set shutter and ISO, get your f-stop ⢠Exposure Value: read the scene's EV directly ⢠Cine: shutter angle and frame rate for filmmakers ⢠Manual: check your chosen settings against the metered scene BUILT FOR REAL CAMERAS ⢠Camera profiles: save your bodies with their actual shutter and bias limits ⢠Full, half or third stop increments ⢠Configurable shutter, aperture, ISO and exposure bias ranges ⢠Reference lock: freeze a reading and measure scene contrast in stops ⢠Exposure lock for recompose workflows ACCURATE ⢠True spot metering of exactly the circle you see ⢠Full-color light analysis: reads saturated LED and neon light correctly ⢠Verified against professional meters from daylight to low light FREE, NO SUBSCRIPTION Every feature is free, forever. If f/oss saves your shots, there is an optional tip jar.
Lume
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Lume is a professional light meter for film photography and cinema. Meter the light with a spot you drag across the scene, lock the reading, then compose the shutter-aperture pair on click-stop wheels, the way a real meter works. PHOTO MODE ⢠Spot reading with a reticle you drag across the scene ⢠Aperture or shutter priority, third-of-a-stop scales ⢠Exposure compensation ±3 EV and ND filters up to ND1000 ⢠24 film stocks with reciprocity failure correction FLASH ⢠Work out the exposure for a shot with flash: guide number, the power the flash is set to (1/1, 1/2, 1/4ā¦) and the distance ⢠Flash and ambient light are added together, the way they add on film ⢠See how much of the exposure comes from the flash, with a warning past sync speed ⢠On models with LiDAR the subject distance is measured where you aim the reticle CINE MODE ⢠Frame rate and shutter angle ⢠Aperture in tenths of a stop, as used on set LOGBOOK ⢠Save every reading with a photo, the data burned in and the metered area marked ⢠Find your shots in a grid or on a map ⢠Share, or save to your camera roll Metering uses the camera's real metadata together with pixel analysis, continuously calibrated against the sensor. Interface in English and Italian.
Screenshots
Verdict
The clearest difference is in-app purchases: Lume at none against f/oss's 3. Lume also leads on update cadence (every 2 days vs every 6 days) and iOS requirement (18.0 vs 26.0). On price, ads and device support there is nothing between them.
Scored on Price Ā· Rating Ā· Positive reviews Ā· Number of ratings Ā· Update frequency Ā· Ads Ā· In-app purchases Ā· Monetization Ā· Best chart rank Ā· Devices Ā· Requires iOS
Both are free to download. f/oss sells 3 one-off in-app purchases. Lume asks for nothing beyond the download.
f/oss ships an update every 6 days, Lume every 2 days. The most recent releases landed on September 27, 2026 and October 7, 2026 respectively.
| Parameter | f/oss | Lume |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 6 days | Every 2 days ā better |
| Ads | No | No |
| In-app purchases | Yes | No ā better |
| Devices | iPhone, iPad ā better | iPhone |
| Requires iOS | 26.0 | 18.0 ā better |
| Further details ā not scored | ||
| Size | 1 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Luca Tescari | Milo Zoppini |
In-app purchases
f/oss
- Nice Tip$1.99
- Generous Tip$5.99
- Amazing Tip$9.99
Lume
No in-app purchases









