The Negativicer handbook.

What the app does

Negativicer meters reflected light using the iPhone camera and suggests a shutter speed for your chosen aperture. Transfer both settings to your analog camera yourself. The record button logs an exposure; it does not release the analog camera’s shutter.

Your first roll

Open the menu → Cameras & lenses. Add your camera, its actual shutter speeds and a compatible lens. Add a film roll and load it into the camera. Choose your aperture, read the suggested time and take the photograph. Tap the centre record button once to log the frame.

Screen stays awake

The iPhone stays awake while the app is active in the foreground, including while reading its handbook. Backgrounding the app restores the normal auto-lock behaviour. You can still lock the phone using its side button.

Aperture scale

Tap an aperture to select it. Green marks the current value. With a selected camera, the scale uses the entered lens range. Long scales wrap to keep all values visible; the app does not detect the engravings on your lens.

ISO, camera and frame counter

ISO is the working film sensitivity. Without a camera, tap ISO to change it. With a camera, edit the working ISO for its loaded roll in the camera detail. Tap the camera name for camera management. The frame counter opens film rolls; metering alone never advances it.

Freeze, reciprocity and preview

The dotted double-circle freezes or resumes the view and metering basis. The f-in-a-circle toggles long-exposure correction: times above one second are multiplied by the film’s saved factor. Consult film manufacturer guidance for important long exposures. The overlapping circles select compatible black-and-white filters; the spectrum icon switches colour and monochrome preview. Preview is an aid, not a guaranteed film simulation.

Shutter scale

Green marks the suggested time. “125” means 1/125 second. A leading apostrophe means whole seconds; “B 12.0s” means a 12-second Bulb exposure. The scale displays the enabled camera speeds and is not a manual shutter selector.

Metering circle and zone control

The number is EV at the displayed ISO, including calibration. A means an average reading, not aperture-priority mode. Moving the circle away from its original position switches to local metering. In zone mode, drag the zone label up or down to change its target. Double-tap the lower-left correction circle to reset all targets to V.

Record button and menu

The central button logs the next frame of the loaded roll, with exposure, date, lens and optional snapshot and GPS. If no camera or roll is selected, the app opens the appropriate setup screen. It will not create a roll automatically. The gear opens Photographing, then Settings, followed by Handbook, website Tutorials and Privacy.

Camera setup

Add a name and film format. Enable only speeds your camera actually supports and specify whether Bulb is available. A camera’s entered capabilities determine the suggested settings.

Lenses

Enter the name, focal length, widest and smallest apertures; for an f/2–16 lens enter 2 and 16. Assign compatible cameras and optionally a filter diameter. Tap a lens in camera details to select it. Changing lenses keeps the loaded film roll.

Load a roll

Add a roll using a film stock and frame count. It starts under Ready. Load it into a camera before logging exposures. A camera can hold one loaded roll at a time. Working ISO may differ from the stock’s nominal sensitivity.

Finish and develop

When you finish the roll, remove it from the camera in film management. Move it through Exposed, In development and Developed. Removing a roll allows the camera to be loaded again. A roll cannot be deleted while it is loaded; deleting an undeveloped roll shows a warning.

Add and compare

Double-tap a metering circle to add another point, up to four in total. From the second point, the image freezes automatically and all points meter locally. Move them to important scene areas. Hold an additional green point to remove it. Returning to a single point resumes live metering.

How the time is calculated

Each point combines its EV reading with its own target zone. All points contribute equally in EV to one shared exposure. “Z Ø” indicates the combined zone evaluation. Three points often cover shadows, midtones and highlights; a fourth can cover another important area. See the Zone System section for examples.

Reset

Double-tap the lower-left correction control to reset all zone targets to V. Three taps on an empty preview area reset points to the base point and remove the active filter.

Local records and PDF

Settings and film records stay in the app’s protected storage. They are excluded from automatic system backups. There is no app iCloud sync or restore in the current version. Export important rolls as PDF before uninstalling. A PDF contains a roll overview and a page for each logged exposure with available data and snapshot.

Optional GPS

GPS starts off. Enable it in Settings and grant location access to include available coordinates. Turning it off prevents new coordinates but does not remove old ones. You can meter without location access.

Delete a roll

Remove the roll from its camera first. Deleting then removes the roll’s exposures, snapshots and PDFs managed by the app. Copies you already shared or saved elsewhere remain.

No camera image

Allow camera access in iPhone Settings → Negativicer, then return to the app. If an image remains unavailable, stop other camera use, try again or restart the app. Without a valid fresh image, the app does not log a measurement.

Time outside camera range

Change the aperture or check the camera’s enabled shutter speeds. Use Bulb only if your camera supports it. Very long exposures may require film-specific reciprocity correction.

Calibration

Compare with a trusted reflected-light meter using the same ISO and the same subject area. Check aperture, camera capabilities and filters before changing calibration. One full shutter-speed step is approximately one EV. The current film reciprocity correction is a simple factor, not a full film-specific curve.