Any reason to keep THM files (300D)?

[GaryCanonUser]

Shooting RAW with 300D; when copying CRW's to my computer for processing, any possible reason to also copy (and keep) the .THMs? I'm currently using Digital Photo Pro for RAW processing.

My understanding is that they are just a low-quality thumbnail for the camera to use, but I vaguely recall seeing something about them also containing some shooting info on some Canon camera or other...

[F1_Fan]

Yeah, they contain some EXIF data which as near as I can tell is duplicated in the CRW. If I remove the THMs from a folder ZoomBrowser can still find EXIF information.

This is a sample of the EXIF data in a THM (I renamed it to JPG so my EXIF utility could open it)
Filename : CRW_5175.jpg
JFIF_APP1 : Exif
Main Infomation
Make : Canon
Model : Canon EOS DIGITAL REBEL
Orientation : bottom
XResolution : 180/1
YResolution : 180/1
ResolutionUnit : Inch
DateTime : 2005:01:05 21:47:57
YCbCrPositioning : centered
WhitePoint : 313/1000,329/1000
PrimaryChromaticities : 64/100,33/100,21/100,71/100,15/100,6/100
YCbCrCoefficients : 299/1000,587/1000,114/1000
ExifInfoOffset : 320
Sub Information
ExposureTime : 3.00Sec
FNumber : F6.3
ISOSpeedRatings : 200
ExifVersion : 0221
DateTimeOriginal : 2005:01:05 21:47:57
DateTimeDigitized : 2005:01:05 21:47:57
ComponentConfiguration : YCbCr
CompressedBitsPerPixel : 9/1 (bit/pixel)
ShutterSpeedValue : 0.00Sec
ApertureValue : F6.3
ExposureBiasValue : EV0.0
MaxApertureValue : F1.8
MeteringMode : Average
Flash : Not fired
FocalLength : 50.00(mm)
MakerNote : 
UserComment :
FlashPixVersion : 0100
ColorSpace : Uncalibrated
ExifImageWidth : 160
ExifImageHeight : 120
ExifInteroperabilityOffset : 2510
FocalPlaneXResolution : 3072000/892
FocalPlaneYResolution : 2048000/595
FocalPlaneResolutionUnit : Meter
SensingMethod : OneChipColorArea sensor
FileSource : DSC
Unknown (A401)3,1 : 0
Unknown (A402)3,1 : 1
Unknown (A403)3,1 : 0
Unknown (A406)3,1 : 0
Unknown (A500)5,1 : 22/10
ExifR98
ExifR : THM
Version : 0100
Unknown (4097) : 3072
Unknown (4098) : 2048

[tim]

I usually delete them, they're annoying, and the RAW has all the same data as the EXIF. If you upgrade to the latest beta of PS camera raw the exif data will even be put into your jpg - make sure you "save as" not "save for web" though.

[rammy]

I keep the THM's. I use the THM files to provide a thumbnail preview in Windows File Explorer without having to load images into a paint package such as PS.

This saves me having to load the CRW into PhotoShop, just to see what it is.

Yes, I do give my folder structures appropriate names, but some of the folders contain 10's of thousands of CRW files.

I don't use PS File Brower as I have Windows XP with roaming profiles, which PS uses to generate HUGE preview database files for File Browser.

Have a look here:
http://www.suodenjoki.dk/us/productions/articles/raw_thumbnail.htm