Comparison

DoF plus vs BTZS ExpoDev

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

DoF plus

This app helps digital camera owners calculate depth of field, hyperfocal distance, and field of view. It allows customization of camera models, focal lenses, and apertures for precise photographic planning.

Highlights
  • Depth of field calculation
  • Hyperfocal distance calculation
  • Field of view calculation
  • Customizable camera models
  • Customizable focal lenses
  • Customizable apertures
Features
Read full description

DoF plus is a "must have" application for all digital camera owners. DoF plus will answer questions like: - how to ensure that model face will be sharp when shot at 5m? - which focal lens I must use when shooting a person at 10m? a small bird at 50m? - how to maximize image sharpness when shooting landscapes? DoF plus is highly customizable: - select your camera model. Computations will take into account camera specifications. - define your own list of focal lenses from a list. - define your own list of apertures from a list. DoF plus provides following features: DoF (depth of field) Set focal lens, f/stop and focus distance. Near and far focus distances will be computed automatically HyF (hyperfocal) Set focal lens and f/stop. Hyperfocal distance will be computed automatically. Note: when you focus at hyperfocal distance, image will be sharp from half this distance to infinity. FoV (field of view) Set focal lens and focus distance. Field of view (width and height) will be computed automatically.

About

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.

Highlights
  • 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
Features
Read full description

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.

Screenshots

DoF plus4 screens
BTZS ExpoDev4 screens

Verdict

The call

The clearest difference is price: DoF plus at $0.99 against BTZS ExpoDev's $24.99. DoF plus also leads on update cadence (every 2 months vs every 12 months) and rating (5.0 vs 4.8). BTZS ExpoDev's advantage is ratings volume (5 vs 1) and iOS requirement (13.7 vs 18.6). On review sentiment, ads, in-app purchases and monetization model 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

CostPrice · In-app purchases · Ads · Monetization

DoF plus costs $0.99 and BTZS ExpoDev $24.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

DoF plus holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: BTZS ExpoDev has 5 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 80% of DoF plus's written reviews are positive against 83% of BTZS ExpoDev's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

DoF plus ships an update every 2 months, BTZS ExpoDev every 12 months. The most recent releases landed on October 29, 2026 and October 7, 2026 respectively.

Scorecard5 real differences · 5 level
DoF plus versus BTZS ExpoDev: the parameters behind the verdict, then further details
ParameterDoF plusBTZS ExpoDev
Price$0.99 — better$24.99
Rating5.0 (1 ratings) — better4.8 (5 ratings)
Positive reviews80.0% of reviews83.3% of reviews — better
Number of ratings15 — better
Update frequencyEvery 2 months — betterEvery 12 months
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhoneiPhone, iPod — better
Requires iOS18.613.7 — better
Further details — not scored
Size2 MB16 MB
Age rating4+4+
DeveloperJean-Christoph KAISERTinyOctopus, LLC

Customer experience

DoF plus

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews15 reviews
Positive80.0%
Neutral6.7%
Negative13.3%

BTZS ExpoDev

All ratings5 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews6 reviews
Positive83.3%
Neutral0.0%
Negative16.7%

In-app purchases

None

DoF plus

No in-app purchases

None

BTZS ExpoDev

No in-app purchases

Questions

Is DoF plus free?
DoF plus costs $0.99, with no in-app purchases.
Is BTZS ExpoDev free?
BTZS ExpoDev costs $24.99, with no in-app purchases.
Which has better reviews, DoF plus or BTZS ExpoDev?
DoF plus is rated higher. DoF plus averages 5.0 out of 5 from 1 ratings, while BTZS ExpoDev averages 4.8 from 5 ratings.
Do DoF plus or BTZS ExpoDev have ads?
Neither DoF plus nor BTZS ExpoDev shows ads.
Which is updated more often, DoF plus or BTZS ExpoDev?
DoF plus ships an update every 2 months, and BTZS ExpoDev every 12 months. Most recently, DoF plus was updated on October 29, 2026 and BTZS ExpoDev on October 7, 2026.

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