John Sadowsky
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Re: Are these still true?Reply #11 on: May 11, 2021 at 3:50 pm
I’m not buying it.
As I stated, there may have been some justification for early digital cameras. Memory management is Computer Engineering 101. Are we believe that digital camera electronics, which has evolved so dramatically over the years, is stuck with circa 2002 memory management? That’s pretty hard to believe.
An internet search yielded articles that expressed the full range of opinions: from never delete & always reformat; to the risk is very small (and essentially zero with a backup memory slot) for the reasons I just expressed. One article said that deleting images in-cameras “is a great way to scramble the FAT table” (FAT = File Allocation Table). True, perhaps 10-15 years ago, but that’s got to be utter nonsense today.
Personal Experience: I have a Sony A7R3. I delete images in-camera almost every time I shoot and I seldom reformat my disks. I’ve never had any issues with the A7R3. In 10 years of the same practice with a Nikon D700, I experienced one disk failure. That disk was a hard failure – it could not be reformatted. So that was not likely simply a “scrambled FAT.”
Flash drives do fail – but that has nothing to do with deleting files in-camera or reformatting. It is just a failure of an electronic part.
Technical Details
No modern memory system stores files contiguously in memory. Memory is allocated in fixed-sized blocks (typically 256 bytes) distributed across the memory space and intermingled between files. It sounds like a mess, but that’s how memory works. Back in the day, we had to defrag our MS Windows systems because file fragmentation degraded performance. That’s just not true today. You might be thinking this would slow down the system when shooting at a high frame rate. But images are buffered in RAM before writing to Flash, and the overhead of managing fragmented files is negligible. Files are stored as “linked-lists” blocks. Each block points to the next block in the list. The file table contains only one pointer to the lead block in the list. It simply doesn’t matter how much the file blocks that scattered (fragmented) across the memory space.Moreover, reformatting does not “wipe the disk clean,” as some people think. The FBI can still recover data from reformatted memory. The memory management system, including the file table, is stored on the disk. All a reformat does is resets that system. Similarly, “delete all” just resets the file table. There’s not much difference.
JSS
