BTZS ExpoDev vs MeterGlass
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
BTZS ExpoDev
This app helps traditional film photographers accurately expose black and white film using custom film test data. It calculates precise exposures and development times in the field for consistent results and easier darkroom printing.
- Exposure record keeping
- Film Profile, lens, and filter management
- Incident and Zone System metering support
- Depth of Field calculator
- Reciprocity failure adjustments
- Integrated exposure timer
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BTZS ExpoDev is the companion app for BTZS Plotter for Windows that allows you to more accurately expose traditional B&W films using film test data from BTZS film tests. "BTZS meets the iPhone. It's the perfect match of Phil Davis' BTZS with the same device that the rest of my life is on." - Robert Levittan "It has liberated me from having to worry about my negatives, so that I can direct my attention to the important process of making a photograph." - Laura Campbell "Liberation for the traditional film photographer." - Bill Waldron *** Note: This app cannot be used without having your own BTZS Film Profiles that have been analyzed and exported by the BTZS Plotter for Windows application. *** BTZS ExpoDev is the newest generation of ExpoDev for Apple iOS devices. ExpoDev allows you to use your BTZS test Film Profiles to accurately calculate B&W film exposures in the field for consistently exposed negatives that are easier to print in the darkroom. ExpoDev was designed for Large Format film photographers working in any traditional or alternative process (including hybrid processes such as film scanning). Among the many features in BTZS ExpoDev are: ◆ An exposure record keeping system to keep track of all of your film exposures, allowing you to view the exposure details and the development time to use when back from the field ◆ Manages your lists of Film Profiles, lenses, and filters for fast & easy selection when making exposures ◆ Support for both BZTS Incident and traditional Zone System metering methods ◆ Interactively calculates the SBR, Average Gradient, and the EFS for each scene while metering ◆ Support for user-specified filter factors and Large Format bellows extension compensation ◆ A powerful Depth of Field calculator with selectable Circle of Confusion that supports 3 DOF calculation modes (Aperture/Distance, Near/Far Distances, and Focus Rail Spread) ◆ DOF calculator supports both metric and imperial measurement modes ◆ Calculates exposure by either selecting the Aperture or Shutter speed to use ◆ Supports Apertures down to f/2048 (perfect for pinhole work) and Shutter speeds up to 6 hours ◆ An integrated exposure timer than can handle exposure times up to 12 hours ◆ Sophisticated reciprocity failure adjustments for both exposure and development time that are based on lab-produced data for over 90 film and developer combinations ◆ and more... Note: Sample Film Profiles are available for experimentation but they are not a substitute for personal film testing.
MeterGlass
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MeterGlass is a professional light meter built for film and large format photographers. Metering • Average metering and ~1.5° spot metering with a live acceptance-angle readout; pinch to zoom in tighter • Zone System: multi-point capture and placement, scene contrast and N+/N- development suggestions, shareable metering cards • Calibration in 0.1 EV steps against a gray card or a meter you trust Film formats • Nine format masks from 135 to 8x10 (including 6x12/6x17 panoramic) with in-mask metering • Live equivalent focal length per format, portrait/landscape framing, zoom with 5mm detents Exposure • EV, aperture/shutter pairs, exposure compensation, illuminance (lux) and color temperature • Filter factors (yellow/orange/red/ND) and bellows extension compensation, folded into suggestions automatically • ISO 20–25600, apertures f/1–f/256, full/half/third-stop steps Instrument-style interface, six languages, fully offline, zero data collection.
Screenshots
Verdict
The clearest difference is price: MeterGlass at $9.99 against BTZS ExpoDev's $24.99. MeterGlass also leads on update cadence (every 4 weeks vs every 12 months). BTZS ExpoDev's advantage is iOS requirement (13.7 vs 17.0). On ads, in-app purchases 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
BTZS ExpoDev costs $24.99 and MeterGlass $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.
BTZS ExpoDev ships an update every 12 months, MeterGlass every 4 weeks. The most recent releases landed on October 7, 2026 and October 16, 2026 respectively.
| Parameter | BTZS ExpoDev | MeterGlass |
|---|---|---|
| Price | $24.99 | $9.99 — better |
| Rating | 4.8 (5 ratings) — better | — |
| Positive reviews | 83.3% of reviews | — |
| Number of ratings | 5 — better | — |
| Update frequency | Every 12 months | Every 4 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 13.7 — better | 17.0 |
| Further details — not scored | ||
| Size | 16 MB | 4 MB |
| Age rating | 4+ | 4+ |
| Developer | TinyOctopus, LLC | 存滨 崔 |
In-app purchases
BTZS ExpoDev
No in-app purchases
MeterGlass
No in-app purchases









