Canon DSLR News

Potential privacy issue with Canon cameras and copyright info setting

As just about everyone knows, you can enter your custom copyright info in your Canon ILC and it will appear in the EXIF data. If you use the delete copyright information in the camera menu, apparently the deleted information is still actually in the camera, minus one character.

The problem:

Now, you are also privacy-conscious and delete these before selling a camera to a used equipment dealer. You use the camera’s Delete copyright information menu item, thinking that it will remove everything. Unfortunately, this isn’t the case. Besides not touching owner and IPTC fields at all, it only replaces the very first character of the author name and copyright fields with a zero, leaving your previously set copyright information in the camera.

Laszlo at DIRE Studio has found the “bug”. Full disclosure… this issue is being used to sell his ShutterCount app, but you can also correct this issue manually.

If you are selling a camera, or perhaps you rented a camera, you’ll probably want your copyright information fully removed from the camera.

How to fully delete your owner and IPTC info from the camera:

  1. Delete both the owner and IPTC info with EOS Utility.
  2. Go to the camera menu option to add your copyright information.
  3. Fill the author and copyright fields with either spaces or random characters.
  4. In the camera menu, now delete the copyright information.

According to Laszlo, this behavior likely exists on all Canon ILC cameras made since 2007.

AdamBotond

EOS M6 Mark II
Mar 31, 2016
80
7
I have a second-hand Canon EOS 1-DX with the same issue. I couldn't figure out how to remove the previous owner from the copyright information until now. I will give it a try.
 
  • Like
Reactions: EOS 4 Life
Oct 13, 2015
21
14
Germany
It is included in the exif data of the picture. So new owner's images would show as belonging to you if you looked at the metadata. Probably would not hold up in court, but still.

_Brian
That is false, I just checked it.
deleted copyright info is not written to the files.
Regards,
Robert


EDIT: Oops sorry, I misunderstood. You meant the case that you deliberately do not delete the copyright info and hope that the future owner does not notice/ care. That would of course be written to the files. Along with the camera and camera serial number which ha can proove belongs to him. So that would surely not hold up in court.
Regards,
Robert
 
Last edited:

definedphotography

I'm New Here
Mar 13, 2020
24
14
Its just like files on a PC. When you delete them it just sets a bit to say this disk can be overwritten, but the data is still there.

Best thing to do is delete your info, put in random characters and then reset the camera to "delete" it.
 
Oct 13, 2015
21
14
Germany
Its just like files on a PC. When you delete them it just sets a bit to say this disk can be overwritten, but the data is still there.

Best thing to do is delete your info, put in random characters and then reset the camera to "delete" it.
blank spaces are perfectly sufficient, there is no need to randomise.

Regards,
Robert
 

lexptr

Photograph the nature while it exists...
Aug 8, 2014
63
27
www.len-lex.com
Haha! It looks like they somehow write literal zero instead of numeric. In programming (e.g. in C and C++) it is a common way to quickly "erase" text by placing numeric zero as the first character. Because zero marks the end of text. If you mistakenly use literal zero - it will just appear as you've replaced the first character by zero character. Nice. I will have some lulz tomorrow with co-workers :)
 
  • Like
Reactions: zim

SteveC

R5
CR Pro
Sep 3, 2019
1,855
1,716
Haha! It looks like they somehow write literal zero instead of numeric. In programming (e.g. in C and C++) it is a common way to quickly "erase" text by placing numeric zero as the first character. Because zero marks the end of text. If you mistakenly use literal zero - it will just appear as you've replaced the first character by zero character. Nice. I will have some lulz tomorrow with co-workers :)
MS Dos/Windows used to put a tilde (~) at the front of the name listed in the directory, overwriting the first letter of the name, just like we're seeing here. So "My Dog.jpg" becomes "~y Dog.jpg". That entry doesn't just give the name, but also gives a location on the the disk where the actual file resides. They do something else to make that space available again--they typically do something to put that space at the "back of the queue" for reassignment, so that it won't actually be overwritten for a while, until the machine has nothing less recent to overwrite.

The file recovery software that came with the Microshaft operating system (and maybe still does) would check to ensure that none of the actual file got overwritten, then ask you to tell it what that first letter originally was before they replaced it with ~. Once you supply that letter, the directory entry became visible again, and the actual data (stored in some other part of the disk than where the directory entries were) would then be marked as in use again.

(I think modern (Post Windows 95) systems actually do something different. They move the file's directory listing to the "recycle bin" and there it sits until you empty the bin. Even then, perhaps, all it does is put the tilde in and it works like I'm describing. I just don't know.)

All bets are off, of course, if you "erase" a bunch of files and then defragment your hard drive. When you do that, data actually gets physically moved from one location to another rather than just de-listed, and anything marked as presently not in use is up for grabs. So the data that you "erased" will more than likely really get overwritten. Similarly, a low level format will trash the entire structure.

A lot of this is not true for SSDs, by the way. There's no motivation to "defragment" them because an SSD is truly random access. If you read sector 0 then read sector 1,000,000,000, it's just as fast as reading sector 0 then sector 1, unlike with a hard drive that has to re-position the read head in the first case but not the second.

An analogy (which will date me); imagine you record lots of music onto cassettes. But when you're tired of the mix on a cassette, you don't actually erase the cassette; rather you just take the label off and throw the cassette in a bin of "blank" cassettes you can record different music onto. If you actually put it at the bottom of the bin when you do that, you're operating like a Microshaft system's hard drive. It's possible for you to find that cassette and put the label back onto it if you change your mind, but wait long enough and you'll eventually get down to the bottom of the bin and re-use the cassette, and THEN it's gone for good.
 

Kiton

Too deep in Canon to list! :o
Jun 13, 2015
79
54
I would think when you sell the camera you could just go in an change the copyright data to something like I JUST SOLD THIS CAMERA, that will over ride the old data and more than likely motivate the new owner to change it and add their own.
 

mdcmdcmdc

CR Pro
Sep 4, 2020
6
1
Setting the first character to zero disables the string? What did they write the software with, Pascal??!!