ShutterMeter uses the iPhone microphone to analyze mechanical shutter sounds and estimate the interval between opening and closing. Compare repeated results with the selected speed and keep a record for each camera.
Support / 支持： Send questions and bug reports to szpwqq@gmail.com. Include your iPhone and camera models, app version and the shutter speed you were testing. 反馈时请附 iPhone 型号、相机型号、App 版本和测试档位。
Version 1.2 adds JSON archive backup, merge import and CSV export. You can search camera names and notes, or edit a camera profile while keeping its measurements attached. The App Store page shows the version currently available in your region.
Guided three-reading tests help you repeat a speed before moving on. The shutter health map uses the latest three Clear signal results at each speed to show median deviation, spread and tested-speed coverage. You can share a text report, browse camera histories and review exposure compensation guidance. The colorful interface supports Dark Mode, Dynamic Type and VoiceOver.
View ShutterMeter on the App Store. The store page shows the version currently available in your region.
In Cameras, open Archive manager and choose Export full backup. The JSON backup contains every camera profile and saved measurement, including identifiers, camera names and notes, dates, nominal and estimated durations, and signal grades. It does not contain audio, purchase receipts or your free-measurement count.
To bring a backup onto an iPhone with ShutterMeter 1.2, choose Import backup and select the JSON file in Files. Review the new and duplicate counts, then choose Confirm merge. The app adds new items without deleting or overwriting local records. Matching identifiers keep the local version, even if a name or note in the file differs. Deduplication uses identifiers, not camera names. Cancel the preview to leave the archive unchanged.
Export CSV records creates a table of saved measurements, with camera names and notes, measurement dates in UTC, raw durations in seconds, deviation and signal grades. CSV is for spreadsheets and inspection; use the JSON backup to import an archive. Neither file is a calibration certificate.
JSON backup imports and exports, and CSV exports, have a 10 MB file limit. An import must also keep the merged archive within 1,000 cameras, 50,000 measurements and 10 MB, with 1 KB reserved for the backup format header. Oversized or invalid imports leave the existing archive unchanged.
For an offline export in version 1.2, follow Cameras → Archive manager → Export full backup or Export CSV records → On My iPhone → this app's folder → Exports. The app folder may be named ShutterMeter or 快门测速仪, depending on language. Tapping an export creates the Exports folder so it is available in the native Files save dialog, even without iCloud or another file provider. Choose the folder and save the file there.
This app folder is still inside the app's sandbox. Deleting ShutterMeter also deletes files saved there, including exported backups and CSV files. Save important backups to iCloud Drive or another location outside this app folder. Those independent external copies are not deleted when you remove ShutterMeter; manage them separately in the destination you chose.
You choose the destination in Files. Cloud locations and other file providers may sync or transfer the exported copy under their own settings. Import reads the file you select; the app does not automatically synchronize archives between phones. The private measurement store remains outside the Files-accessible Documents folder.
Microphone mode supports 11 nominal speeds from 1 second to 1/60 second, including 1/5, 1/10, 1/25 and 1/50. Camera mode is not enabled; 1/100 and faster speeds are not supported in this version. Clear signal describes the recording quality, not certified accuracy. ShutterMeter has not completed accuracy validation across all speeds against a physical shutter tester. Mirror slap, background noise and shutter design may prevent a usable result.
Use an unloaded camera in a quiet setting. Open the camera back or remove the lens to expose the shutter sound, hold the microphone about 2 to 5 cm away, start a measurement and fire once. Keep still until the result appears. Repeat a speed three times; treat scattered results as a reason to check the setup and retest.
Audio is analyzed on your iPhone. The app does not automatically upload measurement data. A report share or file export can send data to the app or file service you choose, and system device backups may include local records. Apple processes purchases. The first 10 measurements that produce a result are free, and a one-time purchase unlocks unlimited measurements. Archive import does not change purchase rights or free-measurement counts; use Restore Purchases for an existing purchase on another phone. Local archive access is not paywalled. See the privacy policy.
快门测速仪通过 iPhone 麦克风分析机械快门开合的声音，估算间隔时长，帮助你比较标称档位并记录每台相机的变化。三连测和健康地图用于查看偏差与重复性，文字报告可用于交流检修情况。
1.2 增加 JSON 完整备份、合并导入与 CSV 记录导出，并支持按相机名称或备注搜索、编辑资料后保留测量关联。商店当前可用版本以 App Store 显示为准。
在“相机册”中打开“档案管理”，选择“导出完整备份”。JSON 包含全部相机资料和已保存的测量，包括内部标识符、名称、备注、日期、标称与估算时长、信号等级；不包含录音、购买凭证或免费测量次数。
在装有 1.2 的 iPhone 上选择“导入备份”，从系统“文件”选取 JSON，查看新增与重复数量后再点“确认合并”。导入只添加新项目，不删除或覆盖本机档案；标识符相同的项目保留本机版本，即使文件中的名称或备注不同也不会替换。重复判断依据标识符，不是相机名称。取消预览不会改变档案。
“导出 CSV 记录”提供逐条测量表格，包含相机名称、备注、UTC 测量时间、原始秒数、偏差和信号等级。CSV 用于表格软件查看与检修分析，导入档案请使用 JSON 备份。这两种文件都不是校准证书。
JSON 备份导入、导出及 CSV 导出均有 10 MB 文件限制。合并后最多保留 1000 台相机、50000 条测量，且合并档案不能超过 10 MB，并在该额度内预留 1 KB 用于备份格式头部。文件过大或内容无效时，现有档案保持不变。
1.2 的离线保存路径是：“相机册 → 档案管理 → 导出完整备份或导出 CSV 记录 → 我的 iPhone → 本 App 文件夹 → Exports”。文件夹名称可能显示为“快门测速仪”或“ShutterMeter”。点击导出时，App 会创建 Exports 文件夹，让系统“文件”保存对话框提供本地目的地；没有 iCloud 或其他文件服务也能使用。选中该文件夹后保存即可。
本 App 文件夹仍属于它的沙盒，卸载 App 会同时删除其中的 JSON 备份、CSV 等文件。重要备份请另存到 iCloud 云盘或本 App 文件夹以外的其他位置；这些外部独立副本不会随 ShutterMeter 卸载删除，需要在所选目的地单独管理。
保存位置由你在系统“文件”中选择。云端或其他文件服务可能依据各自设置同步或传输副本；导入只读取你选择的文件，App 不会自动在两台手机之间同步档案。私有测量档案保存在系统“文件”可访问的 Documents 文件夹之外。
麦克风模式支持 1 秒至 1/60 秒的 11 个标称档位，包括 1/5、1/10、1/25、1/50 等老标尺。摄像头模式尚未开放，1/100 及更快档位不支持测量。
在安静环境中使用未装胶卷的相机，打开后盖或取下镜头，让快门声音直接暴露。手机麦克风距快门约 2 至 5 厘米，开始测量后只按一次快门，等结果出现再移动。同档连续测三次，确认结果接近后再作为拍摄参考；反光镜拍击、噪声或快门结构可能影响判断。
“信号清晰”描述录音质量，不表示精度认证。本工具尚未完成实体快门测速仪全档对标，健康报告是诊断参考，不替代实体校准。并非每一种机械快门都能得到可用结果。
录音在本机分析，App 不会自动上传测量数据；主动分享报告或导出文件，会将相应数据交给你选择的应用或文件服务，系统设备备份也可能包含本地记录。前 10 次产出结果的测量免费，未识别出结果的尝试不扣次数；一次买断解锁不限次数测量，本地档案管理不受付费限制。导入不改变购买权益或免费次数，换机后可通过“恢复购买”恢复已有购买。购买和恢复购买由 App Store 处理。详见隐私政策。