Immediately Before Photography Event:
For each camera, photograph the CameraTimeSync Cue Card. Do not change the camera’s time.
I suggest using the camera serial number to filter photos by camera, as this is unique. This will avoid the chance of making time adjustments to the wrong camera. For example if you had two Nikon D610 cameras.
1) In Lightroom’s Library module, select Metadata from the library filter. Press the “\” to display the Library Filter bar if it’s not visible.
2) Hover your mouse over the Camera label.
3) On the right side of that column you should see an icon, click that icon and select “Add Column.”
4) A new column will appear with the title “None” click and select “Camera Serial Number.”
1) Download images into Lightroom and gather the image into a single collection. You can also select the folders that contain the images.
2) In Lightroom’s Library module, select Metadata from the library filter. Press the “\” to display the Library Filter bar if it’s not visible.
3) Select a single camera serial number. Only photos taken by that specific camera will be visible.
4) Scroll through the photos looking for the image of the “CameraTimeSync” cue card. Select that image and tap the “E” key or Double click that image. This will open the image into Loupe View.
5) Select all the photos in the tray blow. Menu option Edit –> “Select All” (Ctrl+A or Command+A).
6) From Menu option select Metadata –> “Edit Capture Time…”
7) In the “Edit Capture Time” dialog, for the type of adjustment, select “Adjust to a specific data and time”
8) Adjust the “Corrected Time” to read the same as the time displayed in the “CameraTimeSync” cue card image.
9) Click the “Change” button.
10) Tap the “E” key to return to the Grid View.
11) Repeat for the next camera serial number.
When finished all your photos will be adjusted by the same amount of time that was required to change the data and time to the CameraTimeSync image you selected in step 4. in other words, if your camera was 10 minutes fast, then all the photos selected will have 10 minutes added to them.