Emulsa Accessibility

Emulsa Accessibility

Emulsa is designed to be fully usable with VoiceOver. You can preview, crop and scan a whole roll without a mouse, and hear what’s happening at every step.

Getting started with VoiceOver

  1. Turn on VoiceOver: Command-F5.
  2. Open Emulsa. The sidebar’s sections (Scanner, Source, Film, Frames) are headings. Use VO-Command-H to jump between them.
  3. Choose your scanner, the source (Negatives, Slides or Flatbed), your film stock and format. Each row says its name and “selected” when chosen.
  4. Press Command-P to preview. You’ll hear “Preview done. Found 12 frames.”
  5. Step through frames with Option-Command-] and Option-Command-[. Each frame is announced with a short description.
  6. Press Command-S to scan. You’ll hear each frame as it scans, each file as it saves, and “Scan complete.”

(VO means Control-Option.)

Scan menu
Preview: Command-P
Scan: Command-S
Cancel: Command-Period
Show Negatives: Command-1
Show Positives: Command-2
Show Last Scan in Finder: Shift-Command-R

Frame menu
Previous Frame / Next Frame: Option-Command-[ / Option-Command-]
Open Positive (enlarge the frame): Option-Command-Return
Describe Frame: Option-Command-I
Move Up / Down / Left / Right: Option-Command-arrow keys
Make Taller / Shorter / Wider / Narrower: Shift-Option-Command-arrow keys
Add Frame: Option-Command-N
Delete Frame: Option-Command-Delete

In the enlarged view, the Left and Right arrow keys move between frames and Escape goes back to all frames.

VoiceOver actions on frames
Move the VoiceOver cursor to any crop box, frame in the Frames list or positive preview, then press VO-Command-Space for the Actions menu. You can open the positive, move or resize the crop, add a frame after it, or delete it. Every change is confirmed out loud, for example “Frame 3 moved up” or “Deleted frame 5. 11 frames left.”

What Emulsa tells you

  • Progress: connecting, previewing, scanning each frame, saving each file and finishing are all announced.
  • Errors: if something goes wrong, the error is spoken.
  • Sliders: each slider says its name and value, for example “Exposure, plus 0.30 stops.”
  • Histogram: a spoken exposure summary, for example “Balanced exposure, 2 percent of highlights clipped” or “Dark overall, no clipping.”

Frame descriptions
After each preview, Emulsa describes every frame using Apple’s on-device image recognition: how many people it sees, a few likely subjects, and any readable text. For example: “May show tree, building, text: CROSS.”

Descriptions are read with each frame and on demand with Option-Command-I. They’re made entirely on your Mac. No images or descriptions are ever sent anywhere.

Descriptions come from the low-resolution preview, so treat them as hints for telling frames apart rather than exact captions. Subjects are phrased as “may show” for that reason, and small text may be misread. The first description after opening Emulsa can take about 20 seconds while macOS loads the recognition models.

To turn descriptions off, open the right panel’s Accessibility section and switch off “Describe frames for VoiceOver.”

Display
Emulsa follows your Mac’s Dark Mode, and the scanning area is always dark so film is easy to judge.

Known limitations

  • Voice Control hasn’t been fully tested yet.
  • Emulsa doesn’t yet support enlarging its text beyond macOS’s standard sizes.
    If you run into a problem, or something is hard to use with your assistive technology, please tell us. Accessibility fixes are a priority.

Contact
emulsa@jeffersondavis.us