BTZS ExpoDev vs LFTools
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.
LFTools
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LFTools is an app for Large Format and Film Photographers. In version 1.5.0 LFTools contains 2 Tabs. The first one is the 'LF Tools' tab, with several sub sections. Each section has a tool to calculate certain properties which are used in large format photography. Like extended exposure times with regard to bellows extension or the magnification from a bellows draw for a given focal length. The second tab, 'Film Reciprocity', contains the Film Reciprocity Calculator. This calculator is of interest for all film photographers who are interested in long time exposure. With the Film Reciprocity Calculator one can overcome the so called reciprocity failure, which is inherent to almost all films. It is quite simple to use, one just has to select a film, shutter speed and aperture an the tool automatically creates a table with extended exposure times. The app comes with a pre-populated list of films from Ilford. Ilford was the only manufacture who publishes the p factor for their films. Al be it, the user can add its own films for calculation.
Screenshots
Verdict
The clearest difference is price: LFTools at Free against BTZS ExpoDev's $24.99. LFTools also leads on update cadence (every 3 months vs every 12 months). BTZS ExpoDev's advantage is iOS requirement (13.7 vs 18). 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
LFTools is free to download; BTZS ExpoDev costs $24.99 up front. Neither carries in-app purchases, so what you see is what you pay.
BTZS ExpoDev ships an update every 12 months, LFTools every 3 months. The most recent releases landed on October 7, 2026 and September 11, 2026 respectively.
| Parameter | BTZS ExpoDev | LFTools |
|---|---|---|
| Price | $24.99 | Free — better |
| Rating | 4.8 (5 ratings) — better | — |
| Positive reviews | 83.3% of reviews | — |
| Number of ratings | 5 — better | — |
| Update frequency | Every 12 months | Every 3 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Devices | iPhone, iPod — better | iPhone |
| Requires iOS | 13.7 — better | 18 |
| Further details — not scored | ||
| Size | 16 MB | 4 MB |
| Age rating | 4+ | 4+ |
| Developer | TinyOctopus, LLC | Ruediger Merz |
In-app purchases
BTZS ExpoDev
No in-app purchases
LFTools
No in-app purchases








