View Full Version : Questions about the DCIM folder and image numbers

12th of March 2005 (Sat), 13:25
Re the DCIM folder that images are saved to on CF flash cards using a 20D:

1. What logic lies behind the numbering system of folders in the DCIM folder i.e. folder 109, 110 etc?

2. What logic lies behind the number of images saved to each of these folders? Within one DCIM folder, I have had folders as large as 700MB and two other folders with much less in them.

3. Is there a way to limit the size of the numbered folders to make it easier to simply copy these to a 650MB CD?



12th of March 2005 (Sat), 13:39
The 20D stores 100 files per folder, then it creates a new folder.

I don't love it, either...

Good shooting,


12th of March 2005 (Sat), 13:41
1. If you take a look at the number that makes up the folder name and then look at the filenames of the images in any given folder, you'll see that there's a correlationship between the folder number and the high order digits used in the file name.

Each folder can hold 100 images so after the 100th file is written to the folder, another folder is created (the number in the folder name is incremented by one from the previous folder name). This sort of answers your #2 question, too.

3. Not really but you can stick to using 512 MB card so that everything in the card will fit nicely into a 650 MB CD (with a few wasted bytes here and there)

13th of March 2005 (Sun), 13:53
Thanks, but this doesn't match my 20D experience with 1GB cards. When filling up the card, I have one DCIM folder, in which there are generally 2 numerically labelled folders containing (in recent experience) 35 and 74 images, 64 and 55 images, etc. I have had only one folder with 100 images. Any further ideas?


13th of March 2005 (Sun), 14:27
it writes 100 images in order in each folder.

So if you take 100 pictures and delete 40 as you go, you will have60 images in the first folder, then if you continue shooting another 100 and delete 10, there will be 90 in the second folder.

I think that is correct.

13th of March 2005 (Sun), 14:38
Actually, it'll write 100 images to a folder if all of those images are on the same card and you don't delete any of them ...

If your image numbering starts the card in the middle of a 100 number sequence, then you won't have 100 images in that folder on the card. You could wind up with 40 images in a folder if your previous numbering from a previous shoot ended with **60.jpg and you didn't delete any. Then another folder will start with **01.jpg and will go through *100.jpg, as long as all of those images fit on the card.

Basically, a new folder will open to save images every 100 numbers (not necessarily images), and the next folder will start with **01.jpg.

It's a sequential numbering thing ...

13th of March 2005 (Sun), 15:06
AH-HA! Cecil, you've solved it! That fits with my experience - images numbered up to 100 per card, not necessarily 100 images per card.

Now, how do we customize this?


13th of March 2005 (Sun), 16:52
This only depends on how you want to name your pictures. If you want every shot to have an independant numerical sequence, then leave it as it is. When you download the images, they will all fit tgoether as a complete sequence. If not, there is a custom function that will reset the numbering each time you format the card. Then the sequence will start from 1 each time in folder 100. Just don't try and copy these pictures to the same folder as previous shots without renaming something otherwise you will have duplicate names and will overwrite stuff.

13th of March 2005 (Sun), 19:12
The filing system from the card is just a tempory system. What I do is this.....
In PS-CS, I do a batch rename and do something like this.....03-05ds.0001.cr2
translates to...march, 2005, ds (my initials).0001.cr2 With a 4 digit sequence it's gonna be alot of work to fill all the numbers up in one month. With this system, it's easy anytime to find an image especially if you make a file for each month's shooting. I't also very easy to find an adjusted image from the original cause the name follows the image it's just the extension that changes....don

13th of March 2005 (Sun), 19:17
Use DIM from http://alanlight.com and it does all the downloading and renaming for you. You need a card reader, I think.