Card Readers, files, and raw converters.

[phoby3]

I recently got the Lexar firewire card reader and for my .10 cents there is no substitute when transfering files from the D60.

My first question is... does anyone have a strong knowledge of the File structure of the D60?

There are three file folders under the DCIM file structure.

120 Canon which holds nothing which I assume is the folder for user made files, 121 Canon which contains the .CRW files and .THM files (which I understand contain useful information), and a CanonMSC folder which contains .ctg files (I have no idea what they do).

My second question is... what are the purpose of the .THM and .CTG files?

My third and last question is based upon finding a efficient way to transfer needed files from the camera to then computer using the card reader, since Zoombrowser does a. work under OS 10, b. apparently does not recognize card readers, I have gone to using CWR X which does not allow me to preview images, at least to my knowledge.

Any help will be appreciated.


OS
Macs 9.2.2 to 10.2
G4 tower and ibook
Photoshop 7
Lexar Firewire card reader

[Roger_Cavanagh]

WRT to THMs this is a post that Chris Breeze (author of BreezeBrowser) made on his support forum a while back that I kept:

Chris Breeze wrote somewhen:

BTW, is there any good reason not to throw away the CRW THM's?

It is definitely worth keeping them! Here are three good reasons:

1) The thumbnail generator is faster if you keep the THMs. THMs are
used to generate the small and large thumbnail images and this is
much faster than generating them from the larger JPEG embedded in
the CRW file. (Extra large thumbnails are larger than the THM image
and use the embedded JPEG).

2) EXIF data stored in converted JPEGs and TIFFs is more accurate if
you keep the THMs. This is because THMs contain the full EXIF data
including the undocumented Canon MakerNote and this is simply copied
to the converted file. If you don't keep the THMs the EXIF data has
to be generated from the CIFF data held in the CRW file and this is
less accurate. Don't believe what other people may claim, the Canon
MakerNote has not been fully decoded (outside of Canon) and so the
only way to guarantee the accuracy of the EXIF data is to copy it
from the THM file.

3) You can't write IPTC data to raw files if the THMs are not
present. Since the THM file is really a JPEG file with a different
extension it is used to store the IPTC data. The CRW file is a
proprietary format which has no provision for storing IPTC data.

Regards,

Chris

Personally, my guess is the CTG files are some kind of parameter/control file and the CanonMSC folder similarly serves some of management function.

Regards,

[Georgees]

Your 120 folder with nothing in it was an image directory. The .thm as stated by Chris Breeze is a thumbnail/EXIF file related to the crw file of the same name.

The .ctg files are part of the control structure for the camera so it knows whats on the card and how to put more images on it.

You can delete all of this after you are done as long as you re-format when you put the CF card back into the camera.

I usually don't delete the misc folder, just the image folders.

Regards,

George Smith