Return to Digital Photography Articles

Multiple Cameras / Cards

If you are using more than one digital camera and use separate memory cards, you will eventually encounter a situation where the files will have identical names! This is especially likely to happen if you happen to share a memory card between the two cameras and then go back to using separate memory cards.

Why? A default mode of operation for most digital cameras is to auto-increment the highest image serial number seen on the memory card (or the last used in the camera if the card is empty). If you use card A on camera A, shoot until IMG_5123, then put the card in camera B, Camera B will begin to shoot at IMG_5124 until, say, IMG_5145. Now, placing Card A back into Camera A causes Camera A to start at IMG_5146. Shooting with Camera A creates IMG_5146 to (for example) IMG_5160. Placing empty Card B into Camera B will cause the next shots taken to be numbered from IMG_5146 until (for example) IMG_5170.

Now, trying to import the two memory cards will cause the file namess of IMG_5146 to IMG_5160 to collide! You will need to rename something.

Two solutions:

  1. Downloader Pro offers the ability to tag the filename with a special identifier for each camera that you use. Eg. I have a Canon 10d and a Canon S30. If I wanted, I could have my files named like:

    Images from Canon 10d Images from Canon S30
  2. Manually change the serial number (for renaming) to be different for this import batch. In other words, I'll arbitrarily change the files to be:
    Images from Canon 10d Images from Canon S30

I use solution #2. The reason? I don't encounter the "crossover" problem (with image serial numbers conflicting) that often. It has happened with only two import batches so far (out of tens of thousands of photos). You can also get around it by manually resetting the serial numbers within one of the cameras if you notice that the serial numbers begin to get close. And since I don't encounter the problem that often, I don't feel that it is worth adding extra characters to the file name for every file in my database. And besides, there is almost zero impact of changing the serial numbers on the image file names. All it is useful for is to keep file names unique!

Naming format associated with original Canon files

Name Description
Typical directory tree
JPEG file
RAW file
RAW thumbnail
Movie (AVI) file


Reader's Comments:

Please leave your comments or suggestions below!
2009-04-03Fortunato Navarro
 Sherwood, I use the same name format than you. Perhaps you want to check jhead
which can read EXIF capture date and rename the image file exactly as you mention just with option:
jhead -nf %H-%M-%s_%H-%M-%S
and many options to adjust and present exif data.
2009-03-16Sherwood Botsford
 I wrote a small program that renames pix YYYY-MM-DD_HH-MM-SS. IF there is more than one in a second they are sequenced a, b c. Since I can't use two cameras at once this works well for me. If you use two cameras on the same shoot, make sure they keep the same time. This has the advantage that alphabetical order is also chronological order.
2008-07-19Jonathan Wearne
 Great Site. I especially like your articles on file naming. I've settled on reverse date order with a number series as a suffix. The first photo taken today: 080719-001

My partner arrived in New Delhi yesterday and begins a Rajastan tour with Intrepid. She has a Nikon D80. Would be very funny if you said hello to her! Her name is Kelly.

 Hey Jonathan -- Thanks!
PS> I can't say that I ran into your partner -- many of these places were quite populated
 Is there a way to reset the number the camera uses? I have Nikon 4500E and couldn't find how to do that.

Also - I used to import photos using the default windows XP utility that does this by default. It used the 'Picture xxx' and started from 1 every time.

Then I switched to the import of Adobe Photoshop Album, and then pictures started arriving using DSCN0001 (it started from one on the first import and now it grows).

Who sets the number - the camera or Adobe utility? If the camera as you suggest then how suddenly it started from 001 when I switched software?
 I am not familiar with the Nikon digicam, so I don't know for certain how you might be able to reset the numbering. However, if there isn't a menu option for it, you could try one of the following:
  1. Insert a completely blank memory card (either new or formatted by windows XP, then formatted by your digicam)
  2. Rename one of the files on your memory card to DSCN9999 and shoot another photo on the card
The naming scheme that the Windows XP Scanner and Camera Wizard is completely destructive -- ie. it generates the entire filename (and numbering from 001) from scratch each time. However, the naming and numbering that you see with the Adobe Photoshop Album is most likely the real names of the image files that were created by the camera itself. They probably match the filenames that you'd find on the memory card itself (i.e. you open up the memory card drive that appears under My Computer).

In the default settings, Adobe Photoshop Album doesn't rename the files. So the numbering scheme that you see is completely dependent upon your camera and the contents of the memory card that you use to shoot the images, not the computer. If the Nikon digicams work anything like the Canon digicams:

The next photo number is one more than the larger of:
  • The largest image number on the inserted memory card
  • The last image number shot by the camera


Leave a comment or suggestion for this page:

(Never Shown - Optional)