cobra_lite
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Info only - do with it what you will. This is culled from a hand-out that we issued a while back after experiencing some card-write problems.
Memory cards rely on an implantation process which forces the electrons into an insulating layer within the chip itself. They get trapped there.
Because of that process of implantation, earlier memory cards had a very limited lifetime. Current ones are a lot better and reliability has increased to about a million write cycles.
A single write cycle is not merely the action of writing a single image to the card. The cards write a single block at a time; this may total a couple of kilobytes each.
Even if the computer is not interfering with the data on the card it still continuously accesses the card. This action is similar to a write cycle. The longevity of your card is directly affected and can be decreased quite significantly.
A lot of photographers i know plug their card into the computer and read the image directly from the card. If you think about how many millions of times the computer will be accessing the card just to read parts of the picture, by reading and reading and rewriting even small changes you run the risk of reducing that cards life expectancy by half just by reading a single picture.
Some helpful tips on extending the life of your card:
The best approach is to load your memory card, copy the images on it directly to your hard drive. Then take the card out.
Keep the card in the computer no longer than necessary. Do the image downloading from the card, then extract it. Left in the computer it will continuously access the directory, checking the byte order, to see if there are any changes etc. This action is identical to a write cycle so the life of your card is reduced. Dont work on the image while its still on the card. You could easily knock out half of the life expectancy of the card just by doing that with a single image.
Top Tip: Load your card, copy the images from it directly to your hard drive. Then take the card out.
Deleting accidentally.
If the image is deleted, have they really gone?
In many cases, commercially available software will retrieve images that have not been overwritten already, but sometimes even this won't bring them back.
Remember that a card is a removable device as far as the computer and camera are concerned. It behaves in the same way as a small hard drive.
The card has an area called the directory. That area is very important as it keeps track of the files on the disc and on which sectors theyre written.
While that information may be missing, the rest of the data is still there but cant be retrieved. Damage the directory and the card is useless but you cant access it in a meaningful way the files are no longer complete entities.
The directory is ultra important. Many of the problems people encounter are caused by a damaged directory: it may have been overwritten or theres a hardware problem with the card some sectors cannot be read.
More tips to keep your memory card healthy:
After a shooting session, download the pictures, then reformat the card in the camera. The camera then writes a clean directory, dispensing with leftover and unrelated entries. Reformat the card frequently.
If you have accidentally erased the card in the camera, the pictures may still be recoverable. Its only when a camera has performed a long erase that you may be unable to recover the images.
Tips For Healthy Memory Cards
It helps to follow these tips to maintain a cards health and preserve your precious images.
Always reformat the card in your camera each time, after you have downloaded the images to your computer.
Deleting the images on your card while it is in your computer after downloading is not the same thing as reformatting the card in the camera.
Never load nor remove a card into/from the camera during the image transfer process.
Never force a card into a camera.
Always handle your memory card by its edges. Dont touch the cards contact points. Keep them away from dust and moisture. Dont bend or twist it.
Always turn off the cameras power before you load the card or withdraw it.
When using a card reader always move the icon of the card to the trash (Mac), use the safe-eject procedure (PC), then wait a few moment before removing the card from the reader.
Always keep your camera batteries fully charged. If power fails while data is being written to the card both card and data may be damaged.
Keep away from any high static charges, strong magnetic charges and extreme heart and cold and be very careful when handling cards in dry, low humidity zones.
Before editing the images, always transfer them to the hard drive.
Memory cards rely on an implantation process which forces the electrons into an insulating layer within the chip itself. They get trapped there.
Because of that process of implantation, earlier memory cards had a very limited lifetime. Current ones are a lot better and reliability has increased to about a million write cycles.
A single write cycle is not merely the action of writing a single image to the card. The cards write a single block at a time; this may total a couple of kilobytes each.
Even if the computer is not interfering with the data on the card it still continuously accesses the card. This action is similar to a write cycle. The longevity of your card is directly affected and can be decreased quite significantly.
A lot of photographers i know plug their card into the computer and read the image directly from the card. If you think about how many millions of times the computer will be accessing the card just to read parts of the picture, by reading and reading and rewriting even small changes you run the risk of reducing that cards life expectancy by half just by reading a single picture.
Some helpful tips on extending the life of your card:
The best approach is to load your memory card, copy the images on it directly to your hard drive. Then take the card out.
Keep the card in the computer no longer than necessary. Do the image downloading from the card, then extract it. Left in the computer it will continuously access the directory, checking the byte order, to see if there are any changes etc. This action is identical to a write cycle so the life of your card is reduced. Dont work on the image while its still on the card. You could easily knock out half of the life expectancy of the card just by doing that with a single image.
Top Tip: Load your card, copy the images from it directly to your hard drive. Then take the card out.
Deleting accidentally.
If the image is deleted, have they really gone?
In many cases, commercially available software will retrieve images that have not been overwritten already, but sometimes even this won't bring them back.
Remember that a card is a removable device as far as the computer and camera are concerned. It behaves in the same way as a small hard drive.
The card has an area called the directory. That area is very important as it keeps track of the files on the disc and on which sectors theyre written.
While that information may be missing, the rest of the data is still there but cant be retrieved. Damage the directory and the card is useless but you cant access it in a meaningful way the files are no longer complete entities.
The directory is ultra important. Many of the problems people encounter are caused by a damaged directory: it may have been overwritten or theres a hardware problem with the card some sectors cannot be read.
More tips to keep your memory card healthy:
After a shooting session, download the pictures, then reformat the card in the camera. The camera then writes a clean directory, dispensing with leftover and unrelated entries. Reformat the card frequently.
If you have accidentally erased the card in the camera, the pictures may still be recoverable. Its only when a camera has performed a long erase that you may be unable to recover the images.
Tips For Healthy Memory Cards
It helps to follow these tips to maintain a cards health and preserve your precious images.
Always reformat the card in your camera each time, after you have downloaded the images to your computer.
Deleting the images on your card while it is in your computer after downloading is not the same thing as reformatting the card in the camera.
Never load nor remove a card into/from the camera during the image transfer process.
Never force a card into a camera.
Always handle your memory card by its edges. Dont touch the cards contact points. Keep them away from dust and moisture. Dont bend or twist it.
Always turn off the cameras power before you load the card or withdraw it.
When using a card reader always move the icon of the card to the trash (Mac), use the safe-eject procedure (PC), then wait a few moment before removing the card from the reader.
Always keep your camera batteries fully charged. If power fails while data is being written to the card both card and data may be damaged.
Keep away from any high static charges, strong magnetic charges and extreme heart and cold and be very careful when handling cards in dry, low humidity zones.
Before editing the images, always transfer them to the hard drive.
