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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