Why do images get "corrupted"?

One possibility is operator error. Any one of these will do it:

• If you took out the card from the camera before it was finished writing. In this case your pictures are lost since they were never stored correctly.
• If you took out the memory from the reader before it was finished reading (If you use Windows, you should use the 'Disconnect Removable Device' or similar icon and wait for the message that says it is safe to remove).
• If you disconnected the camera (and you were transferring via USB) before the file was completely read. In these two latter cases, the files may be all right on the card.

If none of this is the case, I agree than an the SD card is most likely dead. It can happen with any card, nothing is perfect 100% of the time but if you buy better ones the likelihood of failure is less. The best ones are usually from Lexar, Sandisk (Black or red, not blue) and Kingston.

That is what a JPEG image looks like when the file is corrupted.

By corrupted, I mean a data corruption problem: one or more bits in the file are not what they should be - zeroes becoming ones or vice versa. JPEG is a lot more susceptible than any uncompressed format as a single wrong bit may affect the entire rest of the picture from that point onward, making the bottom half of your whole picture purple or black or something, or non-recoverable (may be rendered as gray or transparent). In this case, the pictures are rotated due to shooting in portrait so it's the same effect, but sideways.

The file may be corrupted because:

• The SD card has gone bad.
• The memory in the camera is bad.
• Your SD card reader at your computer is bad or you have general hardware issues with your computer. Is it self-assembled/do you overclock?
• or the Sd card writer in the camera is bad.

It's most likely the first one, in which case it's an easy fix - throw the card out. But before you do, try another card - of a different brand/batch - in the same camera and see if you get any of the same problems. If you do, then it's time to look into whether the camera is under warranty.

I had similar issues with images on my Nikon D70. Occasionally the camera showed a 'CHA' error message, images written to the card were corrupt (but could be resurrected by a data recovery tool).

As it turned out my camera has contact problems at the CF card slot. Sometimes reinserting the memory card helps, sometimes I have to use contact spray to get my camera to talk again with the CF card.

It's common for this type of corruption to occur when you remove the memory card from the camera, and reinsert it without formatting it. When you pull the card and insert it into a computer, any number of bad things can happen to the card to corrupt it. Your only defense against this corruption is to format the card every time you insert the card into the camera. Formatting the card in camera insures the card is prepared to accept data from the camera. If you format the card and still get corruption then the card is bad.

There is a 'Format Card' option on your Nikon DSLR menu, and perhaps even dedicated buttons for it ( there is on the D90 ). Each time you insert the card, format it and you'll see this type of corruption minimized.

I once had a bad sensor do this sort of thing. Canon had recalled the camera, but by the time I'd found this out it was too late for mine to be repaired/replaced.

Sometimes an overheating camera will behave differently so switch it off after a photography session to let the sensor and electronics cool down a bit.

FWIW, I see these a lot. Common causes have already been given in other answers, you need to determine cause if possible by swapping all hardware involved, reader, cables, different USB port etc.. If it's the memory card itself there's not much you can do, NAND write/erase cycles are finite so may simply be wear.

What I like to add though is that this type of damage can often be repaired. If image displays only partially there's two things I always check:

• File size compared to similar intact files. If you miss for example about 1/3rd of the image AND file size is also about 1/3rd less than comparable intact image then data is simply missing

• Open file in HxD, sometimes you'll find 1/3rd of data simply being zeros or repeating byte pattern (FF FF FF etc.).

If image damage can not be explained by above, the image may be repairable. I made software that first of all removes 'illegal' byte combinations that may cause rest of the image to be grey. In this example there are 4 corrupt areas:

We can now see image actually continues. By removing remaining corrupt data, and replacing it by zeros it is often possible to repair the image to a degree. Rest damage can then be repaired using a photo editor. Example repair:

https://youtu.be/IUUvWXMtfuY

Too late for OP probably, I hope it can help someone else some day.