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Old Oct 21, 2004, 11:36 AM   #1
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I inherited a digital rebel and have been playing with it since June. Have taken some wonderful pictures with it (http://www.flickr.com/photos/memento/ but some of these are with my old camera).

I tried playing with bulb mode the other day. When I "play" I try to leave the CF card pretty much empty as a precaution, so I only had a couple pictures on it and they were not real important. So I took a picture in bulb mode. I have the camera setup to automatically display the picture for 2 seconds. As soon as the picture was displayed, it disappeared in much less than 2 seconds. When I went to playback the image, it was gone. And all my other pictures were gone, too. So I put the card in my Lexar firewire card reader and it was blank. What happened? I have not had the chance to try it again to see if it's repeatable.
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Old Oct 22, 2004, 1:44 AM   #2
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I've had a card go blank a couple of times. I think that it's a bug in the software / hardware interface, whereby the file system on the card is corrupted / not fully updated at the time of removal. In one case it might have been related to accidentally shooting before the card was inserted.

Running checkdsk / drive check will fix the file system and recover the files in this case, but also leave those files unreadable by the camera software because of extra garbage at the end of the file.

There are several CF file recovery tools around -- perhaps one of those will address this problem.

If you do have this problem, and don't really need to recover those files, you can make the card reusable by simply re-formatting it. You might need to reformat it in any case.

Whatever you do, be sure to take some test shots and transfer them from the camera to the computer before you trust that camera / card, and be careful to ensure that the drive operations are complete before moving the card / etc.

Of course, you could have some other problem altogether.
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Old Oct 22, 2004, 2:07 AM   #3
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The camera gremlins were hungry. The last owner must have forgot to feed them.:G . The previous answer covers it prety well though.
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Old Oct 22, 2004, 4:38 AM   #4
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Try to disable the 2s playback... It put extra bandwidth on the card access cycles.

Also check the state of the battery, an old battery can also do a lot of weird thing. As I recall the shutter opening is what cause the current drain and on fast shutter speed it's OK, but now you're now on bulb...
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Old Oct 22, 2004, 7:31 AM   #5
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Thanks for the responses. I tried running a number of recovery programs, but none could recover the files (not a big deal THIS time). Also I do not run windows at home, so the FAT format tools I used were unix based.

But my concern is not recovery, it is prevention. I accept computer gremlins every day at work (windows) but I do not expect them on my camera or on my home computer (OSX/unix).

I guess I'll have to try to repeat it and see. If it's repeatable, then it's a bug.
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Old Oct 22, 2004, 8:59 AM   #6
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memento wrote:
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Thanks for the responses. I tried running a number of recovery programs, but none could recover the files (not a big deal THIS time). Also I do not run windows at home, so the FAT format tools I used were unix based.
Chances are, the FAT was already currupted when you were shooting. I'd format the card with the camera before shooting (personally, I've always formatted cards this way after each use, since it's just as fast as deleting the files anyway, and insures I always start out with a fresh FAT). I also avoid writing to the card with anything except for the camera. By writes, I mean formats, deletes, or anything that performs any kind of write ona card. Sometimes readers have been known to corrupt cards due to flaky drivers and/or caching from the operating system.

For example, I recently saw a user that tried numerous techniques to update the firmware in his camera via a Lexar card reader without luck. Well, the problem turned out to be that the update was being corrupted by the reader's drivers (or operating system), even though the file looked to be fine on the card (directory entry size, etc). He had tried to upgrade for days using different cards, different techniques, etc. He tried a different card reader, and it worked fine.

IMO, formatting the card with the camera prior to each use is a much more reliable way to go.

As far as recovering files, don't run chkdsk first. This will ruin your chance of recovering the images inmost cases (since it will write out lost clusters, and the image recovery packages will not be able to associate them with the rest of the image file -- since the cluster will either contain more data than the image, or less data than the image). I've seen more than one user ruin their chances of recovering images by runninig CHKDSK.

Use a dedicated image recovery product when you have this problem (not a product designed to fix disks).

These products are usually smart enough to read all of the sectors on the card, without any need for FAT entries, then reconstruct the images for you, saving them to your hard disk. I am not familiar with any Unix based products of this type. Most are designed for Windows.

A good free product is Digital Image Recovery. You'll see the dowload link inthe first message in this German Forum:

http://www.foto-erhardt.de/foto-forum/viewtopic.php?t=2690

It's a .zip file, so you'll need Winzip to extract the installation file. If you don't have it already, you can download a working eval version of Winzip from here:

http://www.winzip.com/ddchomea.htm

The program will let you select English as a language. As long as your camera appears as a removable drive; simply select the drive letter for your camera as the source drive, then select a folder on your PC as the destination (you'll see a browse button to select a folder).

Leave all other settings as default and click the Start Button. It will then search the memory card and save all of the recovered files to the folder you selected on your PC's hard drive. Ifyou leave the prefix for the files as the default, your images will be saved as image1.jpg, image2.jpg, etc.

This product will not work for your .crw files if you shoot in RAW. If you need a commercial product that supports RAW, tryImage Recall:

http://www.flashfixers.com/software/
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Old Oct 22, 2004, 9:43 AM   #7
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thanks. I usually erase the images while still in the card reader after downloading them and I occaisionally format the card in the camera. I will now format in the camera after each batch. That sounds like a good preventative measure, which is really what I'm looking for.

And thanks for the links to image recovery software, but I can't use any of them (or chkdsk for that matter). I don't run windows.
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Old Oct 22, 2004, 2:36 PM   #8
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This is how the 'Gremlins' manifest themselves: http://www.i3a.org/pdf/DigitalCamera...yStandards.pdf

ie the other electrical 'noises' that you can't see, except with instruments
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