HELP. SD Card cannot be opened

shawn said:
Don't leave them on the card. "Develop" your shots after taking them.

Shawn
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I usually transfer all images to an external drive after each outing even if the card has plenty of storage room left on it. Just to be on the safe side.
 
What is the most heavily touched block of information on a FAT file system? The File Allocation Table. When you do a quick format of a FAT file system, it's the File Allocation Table alone that is re-written; that's why you can still recover data from the volume.

The File Allocation Table (FAT) is always written in the same logical location; it has to be. So on a flash media device, the part of the device that is most heavily used and written to is the part that contains the FAT. If you always reformat the card after every use, you are adding yet another read, erase, write cycle to the FAT block.

What causes a flash media device to "wear out"? The number of write cycles to the various physical locations on the device. The usual number of write cycles before a location becomes unusable (aka unreadable) is in the hundreds of thousands ... far more than most uses ever require for the practical use life of the devices thus far since most flash storage devices are replaced in favor of larger/faster/newer design one long before location "wear" has had an impact.

But formatting a flash media device every time it is used is just adding to the normal, expected use model. It is possible that you are increasing the probability of failure by reformatting every time since you are exercising write cycles to the most used portion of the device every time you format it.

Some file system software can relocate the FAT block when it is formatting the device, but most does not. I believe the SDFormatter app does since it analyzes the card and optimizes the creation of its file system, and the SD card format protocol includes a table of write counts and locations external to the file system. Most in-camera formatting is not so sophisticated.

I format cards for all my cameras periodically with SDFormatter. If I need space on a card that's getting too full, I erase (not format) already archived files that are on it. File by file erasure writes far fewer locations in the FAT block than formatting.

My Leica M-D does not even include in-camera deletion options, never mind formatting. I format the card I'm going to use in the M-D with SDFormatter and use it until it's full. I've not once had a single card error in the M-D, and it's been used with the same card since I bought it and has been "filled" several times with over 2000 image files.

Just saying.

G
 
raid said:
Isn't it a special Leica cord?
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Raid, it's a standard usb connection, nothing special to Leica. The Camera end is somewhat trapezoidal in shape, you can get them on Amazon or probably your local camera or computer store.
 
Godfrey said:
What is the most heavily touched block of information on a FAT file system? The File Allocation Table. When you do a quick format of a FAT file system, it's the File Allocation Table alone that is re-written; that's why you can still recover data from the volume.

The File Allocation Table (FAT) is always written in the same logical location; it has to be. So on a flash media device, the part of the device that is most heavily used and written to is the part that contains the FAT. If you always reformat the card after every use, you are adding yet another read, erase, write cycle to the FAT block.

What causes a flash media device to "wear out"? The number of write cycles to the various physical locations on the device. The usual number of write cycles before a location becomes unusable (aka unreadable) is in the hundreds of thousands ... far more than most uses ever require for the practical use life of the devices thus far since most flash storage devices are replaced in favor of larger/faster/newer design one long before location "wear" has had an impact.

But formatting a flash media device every time it is used is just adding to the normal, expected use model. It is possible that you are increasing the probability of failure by reformatting every time since you are exercising write cycles to the most used portion of the device every time you format it.

Some file system software can relocate the FAT block when it is formatting the device, but most does not. I believe the SDFormatter app does since it analyzes the card and optimizes the creation of its file system, and the SD card format protocol includes a table of write counts and locations external to the file system. Most in-camera formatting is not so sophisticated.

I format cards for all my cameras periodically with SDFormatter. If I need space on a card that's getting too full, I erase (not format) already archived files that are on it. File by file erasure writes far fewer locations in the FAT block than formatting.
Click to expand...

The FAT doesn't have to be written to the same hardware place all the time, just the same logical place. That is what wear leveling is about, if the card supports that. If it is actual FAT than the table is also duplicated for redundancy.

I'd argue that formatting doesn't really make any difference than simply deleting files does. The FAT table has to record the location of every segment of a file. If you delete (instead of format) you are still writing to the fat to remove old file location entries. If you are using exFat then it also is updating the free space map.

Shawn
 
shawn said:
True.

But then I've never had scratches, dust, bad processing, water marks, QC guy cutting into my image, light leaks, frame overlap, curling, sprockets tearing or failure to advance with my SD cards. ;)

Shawn
Click to expand...

When life gives you lemons..

(FYI I always ask for my film returned uncut. I like to mess it up myself instead of paying someone to do it)
 
Darthfeeble said:
Raid, it's a standard usb connection, nothing special to Leica. The Camera end is somewhat trapezoidal in shape, you can get them on Amazon or probably your local camera or computer store.
Click to expand...

Thanks! I will check it out. I may need to connect the camera o the PC one day. You never know.
 
shawn said:
The FAT doesn't have to be written to the same hardware place all the time, just the same logical place. That is what wear leveling is about, if the card supports that. If it is actual FAT than the table is also duplicated for redundancy.

I'd argue that formatting doesn't really make any difference than simply deleting files does. The FAT table has to record the location of every segment of a file. If you delete (instead of format) you are still writing to the fat to remove old file location entries. If you are using exFat then it also is updating the free space map.

Shawn
Click to expand...

Yes, but it tends to be depending upon the OS file system software. The file system software in-camera tends to be very minimal and simplistic, and hits the same spots over and over again.

File deletion of course accesses the FAT too, but generally is much simpler in-camera: it just deletes the file entry from the table. All the other links are lost that way.

This is why I only do formatting with SDFormatter and my desktop computer. I know its a heck of a lot more sophisticated and does a better job than any in-camera formatting. I can't do much else with my Leica M-D ... it has no user facing file management tools... :)

G
 
Raid, pm jsrockit. John had a corrupted card once and sent it out to recover the images. He could tell you what company it was. It's not cheap though from what I remember. I don't think many of the consumer software solutions would help much.
 
stompyq said:
Raid, pm jsrockit. John had a corrupted card once and sent it out to recover the images. He could tell you what company it was. It's not cheap though from what I remember. I don't think many of the consumer software solutions would help much.
Click to expand...

I managed to open the card in the end, and I downloaded all image files from it. Thanks!
 
Interesting discussion; I have often wondered if there are parts of drives and media card that are never used because they are at the end - so to speak.


Regards, David
 
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