ZoneCalc, an iOS app for field exposure calculation.

[sukjer]

Moderators note: This thread has been split off from the following thread, where the quoted post from @Evan_Mathis resides: https://www.photrio.com/forum/threa...he-zone-system-in-an-app.217978/#post-3002421

Howdy all, I'm new. But I've been shooting film for a very long time. Over the last few months I've been trying to get my process a lot tighter, and to figure out how I can have a better system to log / catalog the various processes / film / developer combinations and what the tangible effects are. As a started playing with it, I shared some screen shots with other film nerds and folks began to ask if I' consider actually making my tool into an app. So, I built a macOS tool to organize densitometry data and make comparisons easier and more consistent and now I'm sharing it with some other folks that might find it useful

The app is called ZoneLab and is currently in public beta.

View attachment 415337

It’s designed around traditional zone / step-wedge testing: recording density values, calculating effective ISO, gamma / CI, tonal range, and exposure latitude, and allowing direct comparison of multiple tests on the same graph. This has been especially useful when evaluating development time, dilution, or film batch differences.

There’s also a simplified ISO-only mode for quicker EI checks.
Tests can be entered manually or via a USB densitometer (Printalyzer is currently supported), and all data is stored locally. CSV import/export is included for long-term record keeping or independent analysis.
I'm looking to add additional densitmeter integrations and curious what folks are using if they have USB / Serial connection capabilities.

Hopefully this is an easy entry point for folks getting into the Zone System and / or sensitometry, and was designed to reduce friction in the measurement and evaluation side of the workflow. If you’re already doing your own testing and care about repeatability, it may be of interest.

You can get the app free here: https://zonelab.app

I'm curious if this is useful for this community? I'm happy to answer any questions.

Great timing on sharing this. Densitometry logging is exactly the kind of friction that makes Zone System testing feel more daunting than it needs to be – the comparison graph feature alone looks like it would save a lot of manual note-keeping.

I've been working on something that covers the other end of the same workflow: ZoneCalc, an iOS app for field exposure calculation. Where ZoneLab handles the lab side (density values, EI, CI calibration), ZoneCalc covers what happens when you're standing in front of the scene – two-point spot metering, a full 11-zone table with calculated shutter times per zone, N-development recommendations (N-2 to N+2) for D-76, Rodinal, HC-110, XTOL and ID-11, and reciprocity failure correction for 11 film stocks.

The two tools don't overlap – ZoneLab gives you the calibrated data, ZoneCalc uses that understanding in the field.

https://apps.apple.com/app/id6772102746

Curious what the community finds most missing on the field side.

 

[MTGseattle]

I've been trying to square away the math in my head and actually commit the zone system basics to memory again. I don't get out shooting often enough so I'm hoping the app will keep me from making silly mistakes.

 

[Ardpatrick]

I just downloaded this, thought it interesting and yet noticed an obvious limitation. So I upgraded to the Pro version in the hope it overcame the obvious problem and I started playing around.

I’m sitting on a long solo train journey and I have a camera bag with my Sekonic L-558 to hand. So my first impressions are minus film testing.

It’s a nice interface with a concise set of functions- exactly what’s needed in the field. But there is a glaring weakness that is critical, and yet should not be difficult to fix:

Aperture is set in whole stops in the App. My Sekonic, like many spot meters, reads out including 1/10th’s of a stop. I cannot input those fractions into the App’s calculation.

At a minimum the App needs the capacity to input 1/3 stop increments. Anything less means I have to mentally compensate for the discrepancy between say f.8 and f.8.4

Once I have to mentally compensate for an input limitation of the app, it starts to become an impediment instead of an aid.

To extend this feedback - ISO settings are also limited. I shoot Delta 100 at 80 ISO. If I use a yellow filter I usually compensate a whole stop - rating the EI of the film as 40 ISO. Let’s just say this is my personal EI.

There’s no dropdown selection for 40 ISO. Nor for 80 / 160 / 250 etc. These are all very commonly used ISO settings. As with the aperture input, likewise with ISO, nobody wants to have to mentally compensate for the input limitations of their exposure calculator tool. It’s a non-starter.

The Dev settings are likewise interesting but also not quite useful. It would be great to be able to customize the processing times templates based on user prior experience rather than generic and often flawed times derived from the Massive Dev chart.

Finally some of the input settings are laggy on my old iPhone 12 Pro. Not sure if that’s just my device.

Please allow more settings options - seems a relatively simple update, and it would make the App genuinely useful.