Frequently Asked Questions

ShutterCheck doesn’t recognize my camera
Please follow these steps in order to fix the issue:
  • Make sure you’re running the latest ShutterCheck version. Updates can be downloaded from within the app.
  • Check if your camera is supported by the app. The full list of supported cameras is available on ShutterCheck’s specs page.
  • Make sure that built-in camera Wi-Fi is disabled if you have a Wi-Fi capable device (such as EOS 6D and 70D). Active Wi-Fi interface completely disables camera’s USB communication abilities.
  • If you have macOS 10.15 Catalina you should verify that you’ve granted ShutterCheck the permission to access USB-connected cameras. Failure to do so will prevent the app from being able to talk to your camera.
  • Check that no other application on your Mac is trying to access the camera at the same time. Look for Image Capture, Aperture, Lightroom, EOS Utility, Dropbox and so on. Simultaneous access has unpredictable behaviour — both applications may not work properly.
  • Relaunch the ShutterCheck, reboot your camera and try again.
Serial number of my camera display incorrectly, just a few digits instead of a full number

This is a known issue that affects several Canon EOS models with outdated firmware versions. It’s caused by a bug in camera firmware where Canon developers messed-up a simple integer to string conversion by accidentally chopping the lower 32 bits of a serial number.

When ShutterCheck asks a camera about its serial number the special PTP (Picture Transfer Protocol) command is issued and device replies with a S/N in form of a text string. Internally in camera a S/N is stored as a 64-bit integer value, so an int-to-string conversion is needed. Imagine you have a serial number 63850724266. In a full 64-bit big-endian hex it would look as 0x0000000EDDCCBBAA. Because of the described firmware bug the lower 32 bits (0xDDCCBBAA) of the memory cell get chopped away during the conversion and only the 0x0000000E remainder makes it into the final string resulting in erroneous “14” serial number being reported back to ShutterCheck.

From our testing, the following cameras with specified firmware versions are subject to the S/N issue:
EOS-1D X (3-2.1.1), 5D Mark III (3-1.1.5), 5D Mark IV (3-1.2.1), 6D (3-1.1.9), 6D Mark II (3-1.0.3), 7D (3-2.0.3), 550D (3-1.0.9), 650D (3-1.0.1), 760D (3-1.0.0), Rebel T4i (3-1.0.1), Rebel T5 (3-1.0.1), Kiss X6i (3-1.0.1).

To resolve the issue you have to update your camera to the latest firmware revision. There is no way to fix this from ShutterCheck's side. After the update the reported S/N should match the label at the bottom of your EOS camera body.

How do I know that displayed shutter count is correct?

I’ve spent many months reverse engineering Canon EOS cameras and identified shutter count retrieval method on model to model basis. That is, each camera model has something unique in this process. I’ve also tested the app with every possible EOS camera and always got correct results.

You can make sure the supplied information is valid by simply making a shot and then getting another shutter count reading. Note that camera has to be rebooted in order to get an updated shutter count value. Shutter count will increase by one if you made a shot via viewfinder or even more if you made a Live View shot.

Note that some newer EOS models (1D X Mark III, 90D, 200D II, 250D, 850D, R, Ra, RP, R3, R5, R5 C, R6, R7, R8, R10, M6 Mark II, M50, M50 Mark II, M200, Rebel SL3, Rebel T8i, Kiss X10, Kiss X10i, Kiss M, Kiss M2) and PowerShot (G5 X Mark II, G7 X Mark III) report shutter count in increments of 1000 shots. This means you might have to make much more test shots in order to see counter increment.

When I plug my camera the app displays “This camera is not supported. App functionality may be limited” bar
Unsupported camera message

This happens when you connect a Canon EOS camera that is not yet known to ShutterCheck. Most probably you have a recently-released camera model that is not yet supported by the app. Overview and User information panes should be available, but no shutter information will be provided. I tend to update ShutterCheck as fast as I can get my hands on a new models, so please make sure you run the latest version.

After I use ShutterCheck my camera doesn’t turn off automatically

This is a known issue that happens on some selected EOS models. To re-enable the auto-off feature please turn you camera off and remove the battery. After you put it back auto-off should work as usual.

What does “Possible shots” value stands for?

Possible shots value that is displayed on the first ‘Overview’ information pane stands for a number of shots that you can take with your current image quality preferences (RAW/JPG + compression) until camera runs out of its storage (CF or SD). Do not confuse this with shutter count!

How do I customise camera owner, author and copyright fields?

These fields are available for customization on a third ‘User’ information pane. Due to Canon EOS firmware restrictions, you can use only ASCII characters. For your convenience, if you try to enter a non-latin text ShutterCheck will automatically turn it into transliteration.

Are there any hidden costs?

No, there are no hidden costs! Unlike some of the alternative apps that charge a fee per shutter actuations reading, ShutterCheck is completely unrestricted after you buy it. I also don’t offer in-app purchases: all features are available with no strings attached. No annoying ads, no subscriptions, no malware. You get a native Mac app from a well-known developer with years of experience.

Have a question that’s not covered here?

Feel free to contact the support human at!

If you’re experiencing a problem with the app please provide the following details:

  • what camera model do you have
  • what version of ShutterCheck are you running
  • what error is being displayed (screenshot is 👍🏻)
  • what are the other circumstances are
  • what steps should be taken to reproduce the issue

I deal with a multitude of software & hardware configurations, so including as many details as possible is crucial for successful resolution of your issue.