If the camera can read and write all parts of the card the card is not
corrupted. Now we have two reports of Apple computers which can't seem
to get a complete handle on flash cards. Maybe I should note that FAT32
(required for flash cards > 2GB) is not a native format for Apple
software? Otherwise I don't know.
Chuck Norcutt
Tom Fenwick wrote:
> I haven't had this problem with partial files, but I've had something which
> may be similar. A 16GB card which the camera would format and fill with
> images and video I could view on camera, but when I put the card in a reader
> the computer could see all the filenames, but only recognised the card as
> 11GB, and reported errors trying to read the files on the rest of the card.
>
> I had hired the kit out to someone else for a day, and they reported the
> problem, but they put it down to having shot images with two different
> firmware versions on the same card. Only when it later happened to me with
> the same card did I realise that it was some kind of flash card corruption
> problem.
>
> I figured since the camera could play/display all the problem files, and I
> really wanted to recover them, I thought it might be worth installing the
> camera software which I'd never previously used and see if there was any way
> to push the data from the camera rather than pull it from the computer. In
> fact this wasn't necessary; the DPP software had no trouble getting all the
> files off the card where Finder, Lightroom etc had failed.
>
> Once this was done I used the Apple disc utility to do a "hard" format -
> scrubbing the card and creating a new volume etc, then formatting it in
> camera, it was back to 16GB and has been totally reliable since.
>
> Obviously I'm talking about a different problem, different camera and
> different software, but I think it could be related? Perhaps a different
> part of the structural information on the card has become corrupted?
>
> The intriguing bit is how the camera was able to fill the card, and the DPP
> software seemed completely unaware of the problem; somehow being able to
> take the camera's word for what it had rather than relying on a bad
> directory structure and getting hung up.
>
> I'm pig headed enough to keep at it until it yields, but not smart enough to
> know what is really going on.
>
> Tom
>
> On 3 July 2010 13:40, Chuck Norcutt wrote:
>
>> Sorry, yes, I did mean camera rather than computer in case #1. Since
>> you could freely view them on the camera the images on the card were OK.
>> Since corrupted images from that card were seen on three computers the
>> only common point is the reader used. Ummm... correction. It could
>> still be the card if the problem is intermittent electrical contacts.
>> It's possible for the card to have made good contact in the camera but
>> to have bad contact when inserted into the reader. But I think that
>> unlikely. If there's a problem there I think it would be the reader.
>> Even if the problem is with contacts the reader (if a CF card) has tiny
>> pins that can bend or break whereas the card itself has sockets for the
>> pins.
>>
>> But this raises another question in my mind. Do you still have that
>> card as it was? If so, can you still view the images on the camera.
>> That would clinch the argument that the problem was with the reader.
>>
>> So, between cases #1 and #2 is doesn't seem that we can pin the fault on
>> the camera. The card might be at fault for poor electrical contact at
>> the time of download or it might be that it happened to fail elsewhere
>> at the time of download but it seems to me more likely that the problem
>> is with the reader for case #1 and with the Mac's finder app for case
>> #2. Having finder be bad strikes me as very unlikely but I can't make a
>> logical case for anything else given the description of the problem.
>>
>> Given that you've said you didn't pull the plug in case #3 it's still a
>> mystery to me. Although, if the card in use was the same card as in
>> case #1 one could make an argument that there was an electrical contact
>> problem with the card when in the reader in case #1 and in the camera in
>> case #3 with both problems the fault of the card. If the card has a
>> poor or intermittent contact it may work at times and fail at others.
>>
>> On a side note do you label your cards? I have 2, 4 and 8 GB cards.
>> The are labeled 2A, 2B, 4A, 4B, 4C and 8A, 8B, 8C, 8D, 8E, 8F. I've
>> never had any anomalous behavior from any of them but if something odd
>> does occur I can easily keep track of which card was involved.
>>
>> As I said before, if you can find some more sophisticated recovery
>> software it may be able to recover your dance images. That's assuming
>> that the write capability of the card didn't fail completely and that
>> the images are actually there.
>>
>> If you can't get that to work I'd next try disk clone software that
>> ignores the directory and just does a sector by sector copy of the
>> entire card on to another one of equal capacity. Then I would format
>> the new copy in camera. Remove it and take it back to the computer to
>> try the recovery software again. With the directory erased by the
>> format the recovery software will have no choice but to try scanning the
>> complete card looking for JPEG file headers. But don't format your
>> original until you've worked first on the copy.
>>
>> Chuck Norcutt
>>
>>
>>
>>
>>
>>
>> siddiq@xxxxxxx wrote:
>>> On Jul 2, 2010, at 5:49 PM, Chuck Norcutt wrote:
>>>
>>>> Ok, I'll try to make as much sense of this as I can.
>>>>
>>>> In case 1 the scenario that makes most sense is that the card
>>>> reader has a problem. I would normally say that the files on the
>>>> card were corrupted except you say you could view them on the
>>>> camera. If so then the images on the card had to be good. Since
>>>> we won't hypothesize that all 3 computers were bad the only common
>>>> thing between them all is the same card reader. But there is still
>>>> a possible fly in the ointment here. When you say you could view
>>>> them on the computer
>>> do you mean camera?
>>>
>>>> do you mean as in successively reviewing images in playback mode or
>>>> was it just seeing them pop up on the screen as they were shot. If
>>>> the latter you could have been viewing just an image in the buffer
>>>> that had not yet been written to the card. If that were the case
>>>> the card could still have been corrupt and you wouldn't have known
>>>> it. That would put the error back on a corrupt card.
>>> If above was supposed to be camera, i could view them successively,
>>> even magnifying some shots in playback mode to check expressions.
>>> Don’t have camera set to review image after exposure.
>>>
>>>
>>>> Case 2 is a total mystery to me except for hypothesizing an error
>>>> in finder since another app, iphoto, is able to display an entire
>>>> image and also export it intact. That says the image on the card
>>>> had to be there in its entirety and was successfully copied to the
>>>> computer.
>>>>
>>>> But surely there is also a case 3? You say you lost *all* of your
>>>> dance images even though you could recover older images with
>>>> recovery software. Losing all of your just shot images is
>>>> consistent with having lost the directory. That could happen if
>>>> the camera was writing and lost power or if the card was removed
>>>> before the writing was done. The last thing that's written is the
>>>> directory update to say where all the files are located. But that
>>>> *shouldn't* happen with a normal power off. The camera is supposed
>>>> to ignore power off until its done writing. Of course, if you
>>>> pulled the card out of its slot before writing was done the camera
>>>> has lost control and you've lost your images.
>>> That’s what I thought too, but I powered off the camera, walked back
>>> to office, and put card into reader. Plenty of time :( Lots of juice
>>> in battery. Wasn’t shooting in AFS or continuous-high-release mode
>>> either.
>>>
>>>> Now then, why did the recovery software find old images. It's
>>>> because there was still an old copy of the directory there and you
>>>> deleted images rather than reformat. Deleting or erasing images
>>>> doesn't eliminate the directory entry that points to that image.
>>>> It only marks the entry as deleted without actually erasing
>>>> anything. The original entry is still there. The camera's file
>>>> system knows enough to ignore the entry because it's marked as
>>>> deleted. But the recovery software says, "Oh, Siddiq wants me to
>>>> recover all this old stuff that's marked deleted." And that's what
>>>> you got. Your original images are probably still there too but,
>>>> because there was a valid but obsolete directory there, that's what
>>>> the recovery software picked up on.
>>>>
>>>> More advanced recovery software could probably get them back but it
>>>> needs to know enough to scan the files themselves rather than the
>>>> obsolete directory. If you had formatted the card rather than
>>>> erased files the recovery software would probably have picked up
>>>> both the new and old images but wouldn't know their camera assigned
>>>> file names.
>>>>
>>>> But I still can't explain everything to my complete satisfaction.
>>>> I'm still bothered by the abberant behavior of the finder.
>>>>
>>>> Chuck Norcutt
>>> After the first occurrence, thought it was some freak accident, but
>>> now that’s it’s happened again, I’m wondering if I should worry :(
>>>
>>>>
>>>> siddiq@xxxxxxx wrote:
>>>>> On Jul 2, 2010, at 3:39 PM, Chuck Norcutt wrote:
>>>>>
>>>>>> I'm having trouble here since parts of the story (as I
>>>>>> understand it) don't seem to add up. The clarifications you've
>>>>>> added on this message and the previous one say the problem
>>>>>> exists with the images as they are stored on the card because
>>>>>> the corrupted images move wherever the card goes. Or is it
>>>>>> maybe the reader? Does the reader move with the card? If
>>>>>> that's true it's the camera, the card or the reader... it can't
>>>>>> be the computer. However you have also stated that, after a
>>>>>> download, images on the same computer displayed by one
>>>>>> application are corrupted but on another application they are
>>>>>> not. That says one of the apps is corrupting an otherwise fine
>>>>>> image. It can't be both ways... or if it is you have a truly
>>>>>> confused problem scenario.
>>>>> Sorries, was posting about two diff times this happened. The
>>>>> first time (last month or so), all the pics on card, in camera,
>>>>> looked ok. Put card in cardreader, Mac saw partial images (most
>>>>> were less than 1/4th). Same card/reader on another mac, and
>>>>> finally a PC, same results, partial images.
>>>>>
>>>>> 2nd time (yesterday), images reviewed on camera fine, but on mac
>>>>> showed as partials in finder, complete in iphoto. if i exported
>>>>> them out of iphoto (after importing them), they showed up
>>>>> complete images.
>>>>>
>>>>>
>>>>>> You haven't used any recovery software on this card have you?
>>>>>> The scenario you describe (some JPEG images are truncated) can
>>>>>> happen if you delete images on the card while you're shooting
>>>>>> and the directory is later lost due to reformatting or other
>>>>>> problems. With the directory gone or damaged the recovery
>>>>>> software may not be able to figure out where some images start
>>>>>> and end because (due to the intermediate file deletions) the
>>>>>> image storage may not be in contiguous clusters. Trying to
>>>>>> read these back may produce only the first part of an image
>>>>>> leaving some amount of the bottom portion chopped off. The
>>>>>> rest of the image is probably still there but the software
>>>>>> can't figure out which intial image fragment it belongs to.
>>>>> The only time I ran recovery app was when I lost the entire dance
>>>>> shoot. Couldn’t recover any dance images (oddly, could recover
>>>>> photos from prior shoots). I rarely delete images on camera, and
>>>>> never via Explorer/Finder. Standard procedure is to first copy or
>>>>> import all the photos to computer, put card back in E3, and
>>>>> delete all (or more recently, format card, just because). I
>>>>> wonder if turning off the camera right after a burst of images
>>>>> had anything to do with it? It was just a power off via rear
>>>>> switch, not a battery-dying power off.
>>>>>
>>>>>> Chuck Norcutt
>>>>>>
>>>>>>
>>>>>> siddiq@xxxxxxx wrote:
>>>>>>> On Jul 2, 2010, at 2:09 PM, Chuck Norcutt wrote:
>>>>>>>
>>>>>>>> Now I'm totally confused. The first part says the images
>>>>>>>> were transferred to the computer OK but something unusual
>>>>>>>> happened to them after they got there. The second part
>>>>>>>> says the problem moved to a different computer along with
>>>>>>>> the card and reader. Got a different card or reader?
>>>>>>> The first time this happend (last month I think), I did try
>>>>>>> taking the card/reader to a PC and another Mac to eliminate
>>>>>>> my own machine out of the loop. all three machines showed the
>>>>>>> same partial image. Mac 10.5, 10.6 and WinXP/sp3
>>>>>>>> Also I don't know what it means (physically) to "re-export"
>>>>>>>> an image from the iphoto library on a Mac. I don't know if
>>>>>>>> that means the image was physically copied to a different
>>>>>>>> place or only that a pointer to it was handed off. There
>>>>>>>> are different implications of each.
>>>>>>> importing copies to the applications photo library/database,
>>>>>>> so diff/new file, not a pointer to the same one
>>>>>>>
>>>>>>>> Chuck Norcutt
>>>> --
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