User guide

1. Getting started

On first launch, UWGrade asks for access to your photos. Tap “Allow Photo Access” and allow full access. With limited access, the app shows only the media you shared and a notice; you can open more files through the system picker.

You don't need an account. The app edits everything on your iPhone.

• Library: the start screen with your photos and videos.
• Editor: tap an item to edit it.
• Camera: the camera icon at the top right (“Underwater Camera”) opens the camera with live correction.
• Settings: the gear icon at the top left opens the settings.

2. Library

Grid and gestures

• The library shows square tiles, newest items first. You change the sort order in the settings.
• Spread two fingers to enlarge the tiles, pinch to show more columns. You can show 1 to 10 columns; the default is 3. The app remembers the last column count you chose.
• Tap to open an item in the editor. There, use the arrows or swipe to page through all visible items.
• Touch and hold to open a menu with “Share”, “Select”, “Favorite”, “Reset Item” and “Delete from Apple Photos”.
• Pull down to reload the library.
• After you close the editor, the library shows the last edited item in the center.

Dives

UWGrade groups media into dives. Each group shows “Dive N”, the date, the time and the number of items. A new dive starts when an item is more than 80 minutes later than the first item in the group. You set the duration and turn grouping on or off in the settings.

Markers on the tiles

• Wave at the bottom left: blue for blue water, green for green water.
• Yellow slider icon at the top left: edited but not yet exported. Checkmark: exported.
• “In Queue” and “Exporting” in the center: the item is waiting for export or is being exported.
• Heart at the top right: favorite. Tap the heart to change the favorite status.
• Duration at the bottom right: video with its length.

You choose which markers appear in the settings.

Filters

The filter icon at the top right (“Filter Library”) offers two groups:

• Water type: “All Media”, “Underwater”, “Blue Water”, “Green Water”.
• Edit status: “Edited, Not Exported”.

When a filter is active, the icon is filled and the number of matches appears above the grid. “Reset Filters” returns to your default filters from the settings. Water type detection runs on your iPhone; the progress appears above the grid (“Detecting n/m”).

Selecting and editing multiple items

Tap “Select” at the top right, then tap the items you want. A bar appears at the bottom:

• “Edit (N)” opens all selected items together in the editor (“Batch Edit”). Settings and export then apply to all of them.
• Share shares the original files through the iOS share sheet.
• Reset clears the UWGrade settings and export markers, restores originals edited in Photos and deletes copies that UWGrade created.
• Trash deletes the items from Apple Photos. They move to “Recently Deleted” in Photos.

Importing

The import icon at the top right opens the iOS photo picker. You can choose up to 50 photos and videos; they open directly in the editor.

3. Editor

Layout

The preview is at the top, the control panel with the tools at the bottom. The preview always stays visible while you work. The title shows “Edit”, “X of N” for multiple items and “Batch Edit” for a multiple selection.

Navigation and view

• Swipe to go to the next or previous item when the preview isn't zoomed in. By default, swiping right shows the newer item. You change the direction in the settings.
• Arrow buttons (“Previous Item”, “Next Item”) also switch items.
• Two fingers zoom up to 8×, double-tap zooms to 2.5× and back. “Reset Zoom” restores the full view.
• Compare: the compare button at the top right switches between “Show Original” and “Show Correction”. The top left then shows “Original” or “UWGrade”.

Status

At the top left, the editor shows the export status: “Never Exported”, “Changes Not Exported” or “Current Version Exported”. At the top right, you can mark the item as a favorite or delete it.

Saving and resetting

UWGrade saves all settings automatically, even without an export. The control panel offers two ways to reset:

• “Reset Current Setting” resets only the selected tool.
• “Reset All Settings” resets all sliders for this item, and for videos for all scenes.

4. Color correction

The toolbar at the bottom scrolls sideways. Below each slider you see a short hint, the current value and, if there is one, the automatic value (“Auto ±N”).

Automatic

• “Water Type”: with “Auto”, UWGrade measures the share of green and blue water and shows it together with the detection confidence. With “Manual”, you set the mix between green and blue yourself.
• “Automatic Look” (look): “Off”, “Conservative” (realistic, the default) or “Cinematic” (denser, richer and stronger). For videos, the look applies to all scenes, or to one scene with “Current Scene Only”; “Apply to All” copies it to the others.
• “Strength”: 0% shows the original, 200% is the extreme reserve. The automatic setting chooses the strongest level at which neutral areas don't tip into red. When you move the slider, automatic strength turns off; “Reset Current Setting” turns it back on.

You can combine all manual sliders with the automatic setting.

White balance

• “Temperature” makes the image warmer or cooler.
• “Tint” shifts between green and magenta.
• “Red Balance”, “Green Balance”, “Blue Balance” change the individual color channels.

Underwater corrections

• “Subject Distance”: with “Auto”, UWGrade estimates the distance to the subject (shown as “approx. X m”), and you can shift the estimate. With “Manual”, you set 0.3 to 10 m. The farther away the subject, the more the app compensates for the color loss.
• “Ambient Light / Depth”: for scenes that look darker or deeper.
• “Turbidity / Backscatter”: reduces haze caused by suspended particles.
• “Red Recovery”: reconstructs lost red.
• “Local Depth Correction”: corrects image areas by different amounts (default 65%).
• “Light Protection”: preserves the warm colors of dive lights (default 65%).

Tones

“Brightness”, “Contrast”, “Saturation”, “Shadows”, “Highlights”, “Dehaze” and “Detail” work as in other photo apps.

5. Presets

The stack icon (“Presets”) in the control panel saves and applies settings.

• “Save as Preset…” saves all slider values under a name. A preset with the same name is replaced.
• “Apply” applies a preset to the current item, and for videos to the selected scene. The item's analysis and crop stay as they are.
• “Delete Preset” removes a preset.

6. Crop, straighten, rotate

For photos, the “Crop Photo” tool (short name “Crop”) opens the “Crop” view. All changes are non-destructive; the original stays intact.

• Aspect ratio: “Freeform”, “Original”, “1:1”, “4:3”, “3:2”, “16:9”, “9:16”.
• Frame: drag the frame or its corners. Use two fingers to zoom up to 8×.
• “Rotate” rotates 90° clockwise, “Flip” flips horizontally.
• “Straighten” levels the image between −45° and +45°. “Auto” detects the horizon and levels the image automatically.
• “Reset” restores the uncropped state.
• “Save” applies the crop. The color analysis then runs on the new crop.

You set the guide grid (“Thirds”, “Golden Ratio” or “No Grid”) and the default aspect ratio in the settings under “Crop”.

7. Follow subject and stabilization

For videos, “Track Subject” (short name “Follow”) opens the “Follow Subject” view. The frame then follows a fish, a diver or another subject and smooths out shake.

• Tap “Suggest Subject”. UWGrade suggests a frame; you can move and adjust it.
• Tap “Start Tracking”. The progress appears as “Tracking Subject N%” with the time remaining.
• Switch to “Preview” to check the result with playback and ±5 seconds.
• Tap “Save”. “Remove Subject Tracking” undoes everything.

Settings:

• “Aspect Ratio” of the frame, for example 9:16 for vertical clips.
• “Subject Margin” (default 35%): space around the subject.
• “Stabilization” (default 55%): how smoothly the frame moves.
• “Zoom Strategy”: “Constant”, “Minimal Auto” or “Keep Subject Size”.
• “Advanced”: “Subject Follow” (how closely the frame follows, default 70%), “Dead Zone” (movement that is ignored, default 8%), “Max Auto Zoom” (up to 3×, default 2×) and “Analysis Quality” (“Accurate” or “Fast”).

8. Videos and scenes

Playback

Below the video are a timeline slider, “Play” and “Pause”, and buttons to skip back and forward five seconds. The timeline covers only the trimmed range.

Detecting scenes

Underwater, light and water color often change within one video. That's why UWGrade splits videos into scenes with their own correction.

• Tap “Detect Scenes”. The analysis shows the percentage and the time remaining and looks only at the trimmed range.
• The scenes appear as numbers 1, 2, 3 … below the video. The active scene follows the playback position. All sliders apply to the selected scene.
• In the settings, you can make detection start automatically the first time you open a video.
• “Detect Scenes Again” replaces the boundaries and scene values; the trim stays as it is.

Editing scenes

“Edit Scenes” opens a dedicated view:

• Drag a boundary on the “Scene Boundaries” timeline. The video shows the position live while you drag.
• “Scene +” adds a scene at the playback position.
• “Set Marker” moves the start of the selected scene to the playback position.
• “Delete Scene” removes the selected scene (not the first one).
• Each scene card shows the time range, the transition type and the water mix.
• “Done” closes the view; you then edit the selected scene with the sliders.

9. Trimming videos

“Trim Video” opens the trim view.

• Drag the green “Start” handle and the orange “End” handle. “Trim Range” shows the new length.
• Use “Preview” to play the range.
• With “Save”, you choose “Save as Copy” or, for media from Apple Photos, “Modify Original”.
• “Apply Trim” saves the trimmed video to Photos right away, still without color correction. The correction follows when you export.
• “Reset” restores the full length.

Scene detection, preview and export always use the trimmed range.

10. Exporting

Choosing the output

The “Output” tool in the control panel sets how each item is saved:

• “Edit Original”: UWGrade saves the correction as an edit of the original in Photos. You can revert it at any time.
• “New Copy”: UWGrade creates a new file in the “UWGrade” album. The app always saves imported media as a copy.
• “Color Range”: “Compatible” (SDR, displays everywhere) or “Keep HDR”.
• “Reset Photos Edits” restores the original in Photos. This also removes edits from other apps.

Starting the export

Tap “Export” at the top right. The export runs in the background, and you can keep working right away. More exports join the queue. While an item is waiting, the button reads “Remove”, and during the export “Cancel”. Preview and export look the same.

Under “After Export”, you choose what happens after the export: show the selection, previous item, next item, stay on the current item or go to the library.

Export status

While exports are running, the “Export Status” icon appears at the top right of the library. The view shows each item with a preview image, its progress and, for videos, the time remaining. You can remove individual items from the queue, cancel the running export or speed it up with “Prioritize Export”. By default, using the app takes priority over the export.

The export keeps running when you leave the app, as long as iOS allows it. After that, it pauses and resumes automatically the next time you open the app. You need at least 512 MB of free storage to export. If you want, a notification tells you when it's done (“Notify When Finished”).

Formats and metadata

In the settings under “Export”:

• “Photo Format”: “Automatic”, “HEIC” or “JPEG”. “Photo Quality”: 70–100%, default 92%.
• “Video Codec”: “Automatic” (HEVC), “HEVC” or “H.264”. HDR is kept only with HEVC.
• “Video Resolution”: “Original”, “Up to 4K” or “Up to 1080p”. “Video Quality”: “Efficient”, “High” or “Maximum”.
• “Metadata”: “Everything Possible” keeps all data from the original, “Without Location” removes the capture location, “Minimal” writes no original data.

11. Camera

The camera shows the color correction before you take the shot. It's built for the underwater housing: every function sits on a large button and works with one finger. There are no swipe or pinch gestures.

Use your iPhone underwater only in a suitable, watertight underwater housing.

Opening and closing

In the library, tap “Underwater Camera”. “Close” quits the camera; during a video recording, the app asks first.

Status bar

The top shows the recording status, the time, the battery level, the device temperature with a forecast until overheating, and for video the recording time, the remaining storage time and dropped frames, as well as ISO, shutter speed and color temperature. If the iPhone gets hot, the app throttles the preview; the recording stays unchanged.

Taking photos and videos

• “PHOTO” / “VIDEO” switches the mode.
• Shutter button: white ring for photos, red dot for video. The volume buttons and Camera Control also take the shot.
• UWGrade saves captures to Photos in the “UWGrade” album.

Lenses and zoom

• The lens buttons show only the lenses of your iPhone, for example “0.5×”, “1×”, “5×”, with their zoom range.
• “LENS AUTO”: a tap jumps to the lens's zoom; iOS may switch lenses. “LENS FIX”: the selected lens stays fixed.
• “ZOOM −” / “ZOOM +” zoom in small steps; touch and hold to zoom continuously. This also works during recording.
• The zoom display shows the zoom and the real resolution of the next capture. A tap jumps to the next lens or to the 2× crop of a 48 MP sensor.
• “MACRO” locks the ultra wide lens for close-ups. The button appears only on iPhone models with macro capability.

Focus, exposure, light

• Tap the preview to set focus and exposure on that spot. Touch and hold to lock both (“FIX”).
• Focus button (“AF-C”, “AF-S”, “AF FIX”, “MF”) switches between autofocus and manual focus. “NEAR” / “FAR” set the focus manually.
• “EV +” / “EV −” adjust the exposure in steps of 0.1.
• “LIGHT” turns the flashlight on and off. It's always off at launch and turns off when you leave the camera.
• “GRADING ON” / “GRADING OFF” turns live correction on or off for preview and recording. The look follows the “Automatic Look” setting.
• “SLEEP” dims the camera and saves battery. A tap wakes it; this first tap doesn't take a shot.

Camera settings

The settings button opens a sheet with four tabs. You can't change settings during a recording.

• “CAPTURE”: “Quality” (“Save Storage” 12 MP, “Balanced Quality” 24 MP, “Maximum Quality” 48 MP, depending on the sensor), photo format HEIF or JPEG, frame rate (24 to 120 fps, depending on the device), “Video Bitrate”, 4K or 1080p and “10 BIT” (iPhone 12 and later).
• “AIDS”: grid, horizon (level, green at less than 1° tilt), peaking (red edges in focus), zebra (stripes on overexposure), histogram, maximum display brightness, temperature, overheating forecast and the display of ISO, shutter speed and kelvin. Aids change only the preview, never the capture.
• “MANUAL”: focus mode (continuous, single, locked, manual), exposure mode with ISO 25–2000 and shutter speed 1/4 to 1/8000 s, white balance (automatic, “Lock on Capture”, locked or manual with 2000–10000 K and tint).
• “BEHAVIOR”: sleep mode after 15 s to 5 min or off, “Stay Awake in Sleep”, video stabilization (“Off”, “Standard”, “Cinematic”), haptic feedback and “Customize Controls”.

Customizing the controls

With “Customize Controls”, you move any button by dragging it. Buttons snap to edges and neighbors and, if you want, to their original position. The crossed-out eye hides a button; tap “+” to bring it back. “RESET” restores the default layout. The app saves portrait and landscape layouts separately. You can't hide the shutter button.

12. Settings

The gear icon in the library opens six sections. “Reset All Settings” in the “…” menu resets all app settings; the settings of individual items, scenes, crops and presets stay as they are.

• “Library”: sort order, filters at launch (“Default Filters” or “Remember Last Filters”), default filters for water, grouping by dives with maximum duration (10–240 min), column count with minimum and maximum, and markers for water, export and favorites.
• “Editing”: default look for photos and videos, behavior after export, start of scene detection and swipe direction in the editor.
• “Export”: default output (edit original or copy), color range, formats, quality, metadata and notification when finished.
• “Performance”: export priority, profile (“Balanced”, “Quality”, “Fast”, “Custom”) and preview resolution for photos and videos.
• “Camera”: defaults for quality, formats, frame rate, stabilization, focus, exposure, white balance, 10 bit, bitrate, live correction and all aids.
• “Crop”: default aspect ratios, crop grid and the defaults for following a subject.

13. Subscription and watermark

Without a subscription, the preview, exports and camera captures show large “UWGrade” lettering in the lower-right corner and a subtle “UWGrade” pattern across the whole image. The lettering is white with a dark outline and 10% of the shorter image side high; the pattern runs diagonally at 16% opacity. With UWGrade Pro for €3.99 per month or €29.99 per year, both go away.

• Subscribe: library, “…” menu, “Remove Watermark”. The “UWGrade Pro” page shows the monthly and yearly subscriptions. You pay with your Apple Account; there is no separate account.
• Status: with an active subscription, the “…” menu shows “UWGrade Pro Is Active”.
• Restore: on a new iPhone, tap the button for restoring purchases on the “UWGrade Pro” page.
• Manage and cancel: “Manage Subscription” on the “UWGrade Pro” page, or in iOS Settings under your name and “Subscriptions”.
• Offline: without internet, the subscription stays active until the end of the last confirmed period.

What happens to older captures after you subscribe

• Camera captures: UWGrade keeps a version without the watermark of every capture you take without a subscription. After the purchase, the app replaces the captures in Photos; Photos asks you for permission once.
• Edits and exports: your settings stay saved. Export the item again after the purchase, and the result has no watermark.
• If the subscription ends, the watermark appears again on new results.

Details about the subscription are in the Terms, and answers to common questions are on the Support page.