How can I fix corrupt CRW files?

I'd start by using Canon's ImageBrowser and File Viewer utilities, or Digital Photo Professional. What do they reveal?

However, if your at the File Salvage level, I'm not sure they will fare any better. Worth a shot.

My Sandisk cards came with RescuePro, and Lexar cards came with ImageRescue. However I have had to use neither. Out of the tens of thousands of images shot, I haven't had one failure. So either your CF card is bad (I stick with Lexar and Sandisk) or the camera electronics or pins to the CF card are futzed.

Sandisk rescue pro found and retrieved a whole 2gb card of images after i formatted it twice...

Great software that really saved my bacon. Somehow the transfer to C1Pro became corrupted and the card basically told me it was empty when i reinserted it back in the camera. I formatted the card thinking there was nothing i could do... fired of 2 more shots that read fine, formatted again and went home.

When i got home i tried the Rescue Pro software thinking no way this will work; not only did it find the two images i shot earlier but all the days shoot also (-2 shots I'd overwritten). The most astonishing thing i noticed was it found images at the end of the card that i shot about 6 months prior.. even after countless formats in-between!

FYI. Formating merely resets the file index tables to show file space as now unallocated. It does not erase data space by overwriting the data space with zeroes or ones. That's why RescuePro retrieved your data. Once overwritten, you're into really heavy lifting low level utilities to retrieve any data ... usually through context as much as magnetic anomaly. Hence your overwrites could not be recovered.

In the case of corrupt files, this may be due to real corruption, or lost pointers between file fragments. If lost pointers, these could be recreated but not sure.

Since this is about corrupt files, I wasn't sure if RescuePro would have any impact, as I don't know whether it scans down all the file pointers and finds missing file fragments.

Have fun.

I am curious, was this a Firewire reader or USB? The reason I ask, we had 866 corrupt (unrecoverable by data recovery specialists) out of around 1,300 a couple years back. Never discovered the source of the corruption (to this day the camera and CF card have been working without another incident)- but I did switch to a USB card reader from Firewire.

Mike

So the corrupt files were transfered via the Firewire or the USB reader? I am getting a nagging feeling that transferring RAW files via Firewire is not the way to go. I know my files were imported via a Firewire reader. Firewire being asynchronous "jumbles" the information in some way.

Mike

I never had a problem with any USB reader, but just the one incident with the firewire(lexar). Those images were retrieved but at the time of import C1 Pro was exporting a previous batch and i think that might have influenced the failure.

I've not had any problems with the firewire reader since that one time over a year ago. I've heard of many people replacing the connecting cable and solving issues with FW; USB cables are simply more robust i guess?

For me personally, I am becoming convinced that, all else being equal, Firewire readers are more prone to corrupt camera raw data during a transfer. USB sends information in packets which the computer must reassemble into "information". Firewire on the other hand streams data. My understanding is that the RAW file is, shall we day more delicate, or more susceptible to corruption. Now I am far from being an engineer, but I believe that since the computer doesn't reassemble the RAW file from a Firewire transfer, that it basically accepts the file "as-is", then if header information or other tags come in at the wrong time (since it's streamed), the file gets corrupted.

I may be way off base. But I know I used a Firewire reader when I had my corrupt RAW files (866 out of 1,300+) and since using a USB reader I have had 2 corrupt RAW files out of thousands, maybe even hundreds of thousands.

Mike

I wanted to make another notation that I have also started importing images usually via Image Capture (or some other software) as opposed to just dragging & dropping (copying). I believe this helps prevent corruption.

Mike

I'm not sure I understand how a RAW file can be more or less prone to corruption vs. other formats. I do have a thought on the firewire vs. USB question.

I have found firewire far, far faster than camera usb import (slowest) or USB card reader import.

Now, if Aperture import is slower than desired, or the threads are not handled well (Import is multi-threaded, at least multiple imports or import and other gui activities can perform side-by-side), could it be that the firewire transfer is out-pacing the import routines?

None of this relates back to the original question though of corruption at the CF card source file level.

Hi Dave,

It has been awhile since I really delved into this, but I did find some references to the RAW file more susceptible to corruption. My own experiences bear this out, the 866 anomaly non-withsatnding. In years of working with files, it is only camera RAW files that become corrupt on a "regular" basis.By regular, I mean a couple times a year for me or the frequent posting of corrupt RAW file issues. Hence, the RAW file is more susceptible to corruption. I agree that Firewire import is far faster than USB. I also think that if you are using a program to import the images, you are safer than just dragging the files off your memory card. I believe that just dragging the files off a memory card via a FIrewire reader represents the "greatest" danger. Why? Maybe as you said the firewire outpaces something it shouldn't. Don't know. The other thought that occurred to me is "ripping" a music CD. If I import music via iTunes from a CD, I am good to go. If I copy the files via drag & drop, there are times that I might get audio files that don't playback correctly. So, there is something in HOW the information is imported that relates to how well it "works". Now none of this fixes the current corrupt file problem but it might lead to less corrupt files! But it is possible that the files were not corrupt at the source but rather corrupted during transfer.

As far as getting CS1 to see the file, the only thing I can tell you to try (with a copy) is to replace the.crw extension with a .tif extension and try to trick PS. But if the header information is corrupt, then that won't work.

Mike

You could try removing the HD and putting it in another enclosure. It sounds like a FW issue and may actually be the hard drive's FW connection and not the reader. Being "only" and 80 gb hard drive I'm wondering if it is an older model that needs updated firmware for the FW bridge. Just a thought....