KeyLight PRO vs FilmMeter
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
KeyLight PRO
This app simplifies off-camera flash photography by providing calculators for optimal exposure settings. It helps photographers determine ISO, aperture, strobe power, and distance, removing guesswork for both beginners and advanced users. Manage multiple lighting setups and modifiers with its virtual gear bag.
- Exposure calculators (ISO, aperture, strobe power, distance)
- Key Falloff calculator
- Virtual Gear Bag for unlimited strobe configurations
- Strobe Library with 100+ pre-loaded models
- Support for various light modifiers
- Save multiple setups
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Shooting off-camera flash photography is challenging. Optimal exposure settings requires a knowledge of how to balance ISO sensitivity, aperture level, strobe power and strobe proximity to the subject. Because strobe power varies dramatically not only between manufacturers and models but also when external elements such as umbrellas, soft-boxes and lighting gels are used, quickly determining correct exposure settings can be challenging at best, and frustrating at the worst. KeyLight PRO removes all of this guesswork. Easy-to-use calculators quickly and clearly display optimal ISO levels, aperture settings, strobe power levels and strobe-to-subject distances in an intuitive, familiar interface. For the more advanced photographer, the Key Falloff calculator will calculate the proximity of the strobe from the subject in order to meet a desired exposure value falloff over a specific distance. For example, the area behind a subject is 10 feet away, should be 3 stops underexposed relative to the subject, and the strobe is firing at 1/4 power and the camera is at ISO 400. What should the aperture setting be on the camera? With KeyLight PRO, the answer is a tap away. How many strobes does KeyLight PRO support? The Virtual Gear Bag provides an unlimited number of strobe makes, models and settings, and the Strobe Library provides over 100 pre-loaded strobe model configurations. The Gear Bag is readily accessible on all of the calculators, providing quick, easy and accurate exposure settings when swapping between your strobes. Only using one strobe? Keep multiple "set ups" in your Gear Bag under a variety of configurations: bare bulbed, gelled, soft-boxed, umbrellaed, neutral-density filtered, wall-bounced, go-bo'd. There is no limit to the number of ways the light from a single strobe can be modified. Create as many configurations for these light modifiers as you need, and know in an instant how to most effectively utilize them. KeyLight PRO. Control the light.
FilmMeter
This app transforms your iPhone into a professional light meter for film photography. It offers real-time metering, LiDAR ranging for accurate focus, and comprehensive film roll management. Features include reciprocity calculation, ND filter compensation, and an exposure log to streamline your shooting workflow.
- Real-time light metering
- LiDAR ranging and depth of field
- Film roll and camera management
- Reciprocity and ND filter compensation
- Long exposure timer
- Exposure logging
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FilmMeter turns your iPhone into a professional light meter for film cameras. Real-time metering, LiDAR ranging, reciprocity calculation, and exposure logging — one app covers your entire shooting workflow from loading film to the final frame. Metering Measure exposure in real-time using your iPhone camera. Spot metering reads any point precisely, while average metering balances the whole scene. Full control over aperture, shutter speed, and ISO. iPhone 16 users can meter and adjust EV directly with the Camera Control button. Ranging & Depth of Field Get accurate focus distance with LiDAR-enabled devices. The depth of field scale shows your sharp range and hyperfocal distance, supporting 35mm (full frame) and medium format calculations. Camera Management Create profiles for your cameras and lenses. Set focal length and aperture range for each lens, then link a camera when loading film — aperture selection is automatically constrained to your lens's actual range. Manage your digital film bag the way you manage your real gear. Film Roll Management Create a roll, select your film stock, start shooting. Push/pull processing support lets you set development stops and automatically converts to effective ISO. Each metering links to your current roll automatically. The frame counter tracks remaining shots. Mark rolls as in progress, finished, or developed. ND Filters Built-in support for ND2 through ND10000. Select a filter and exposure is compensated automatically — no manual stop conversion needed. Pair with the long exposure timer to master daytime slow shutter work. Reciprocity Compensation Film loses sensitivity during long exposures. FilmMeter includes reciprocity data for popular film stocks and calculates the corrected shutter time automatically. Long Exposure Timer Long-press the metering button to start a countdown. The timer integrates with Dynamic Island — visible even when locked. Get notified when your exposure completes. No more counting seconds for star trails or light painting. Smart Exposure Suggestions Built-in scene recognition analyzes your frame. In tricky lighting like snow, backlight, or night scenes, it tells you "add one stop" instead of leaving you to figure it out. Exposure Log Every metering saves full parameters and location. Export to CSV. Review your decisions, build your film notes. More Features • ND filter auto exposure compensation • Film LUT live preview • Aspect ratio overlays (135/120 formats) • Focal length frame lines (28-200mm) • Darkroom-friendly red-on-black interface • Metric and imperial units Free to Use • No subscription, no account required • Fully offline, no ads • English and Chinese Designed for film photography. Professional enough for experienced shooters, simple enough for beginners.
Screenshots
Verdict
The clearest difference is review sentiment: FilmMeter at 100% against KeyLight PRO's 44%. FilmMeter also leads on price (Free vs $0.99) and rating (5.0 vs 4.0). KeyLight PRO's advantage is in-app purchases (none vs 4) and iOS requirement (10.0 vs 17.0). On ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
FilmMeter is free to download; KeyLight PRO costs $0.99 up front. FilmMeter sells 4 one-off in-app purchases. KeyLight PRO asks for nothing beyond the download.
FilmMeter holds the better App Store score, 5.0 against 4.0. That said, the two scores are not equally well evidenced: FilmMeter has 41 ratings behind it against 4, so its average is the more settled of the two. Written reviews point the same way: 44% of KeyLight PRO's written reviews are positive against 100% of FilmMeter's.
KeyLight PRO ships an update every 26 months, FilmMeter every 2 days. The most recent releases landed on September 23, 2026 and September 27, 2026 respectively.
| Parameter | KeyLight PRO | FilmMeter |
|---|---|---|
| Price | $0.99 | Free — better |
| Rating | 4.0 (4 ratings) | 5.0 (41 ratings) — better |
| Positive reviews | 44.4% of reviews | 100.0% of reviews — better |
| Number of ratings | 4 | 41 — better |
| Update frequency | Every 26 months | Every 2 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPod — better | iPhone |
| Requires iOS | 10.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 3 MB | 143 MB |
| Age rating | 4+ | 4+ |
| Developer | Daniel Brewer | 宗 侯 |
Customer experience
KeyLight PRO
FilmMeter
In-app purchases
KeyLight PRO
No in-app purchases
FilmMeter
- Buy me a coffee$0.99
- Buy me lunch$2.99
- 请我吃块蛋糕$9.99
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- 赞助开发$19.99
Questions
Is KeyLight PRO free?
Is FilmMeter free?
Which has better reviews, KeyLight PRO or FilmMeter?
Do KeyLight PRO or FilmMeter have ads?
Which is updated more often, KeyLight PRO or FilmMeter?
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