To me it seems prudent to avoid deletion in camera, as mentioned in my latest post (below). I also reformat the memory card in-camera, after downloading and making two copies of all the files on either hard drives or optical media. Call it belt'n'suspenders.
Here are two more reasons not to delete on the street. The first is Murphy's Law. Anyone who habitually makes generous use of the delete key out in the field is eventually going to make a mistake and delete the wrong file. Mr. Murphy assures me that when this happens it's going to be a file that you really, really, really didn't want to lose.
Another reason goes back to something David Vestal said to me many years ago. We were discussing a project I was shooting with 35mm Kodachrome. David said he thought people working with color slides missed out on one of photography's most important tools: the contact sheet. Few photographers cut up their rolls of negative film to save only the shots they like best, but almost everyone shooting chromes edits the takes immediately after getting the slides back from the lab. Jay Maisel used to keep giant NYC wire trash baskets filled with rejected slides as decor in his lower Manhattan studio, to show how tightly he edited his work.
Vestal's point was that when you edit pictures immediately, you are bound to make some mistakes. I've seen this more than once while going back to look at work years after shooting. I dig out the contact sheets and start going over them. I see pictures that I selected to make exhibition prints and remember them as old friends. Then I watch a sequence of shots evolving on the contact sheet and suddenly think, "why in the world did I print frame #13 when #17 is clearly the peak? What was I thinking?" This was the experience Vestal was saying slide shooters will miss.
I've already gone back to my archived CDs or DVDs of digital captures made a couple years ago and found that I disagree with my earlier edit in some cases. So while I narrow down the folders on my working hard drive to a fairly tight edit, I do keep "everything" on optical disc archives. Of course even so we don't yet have digital storage solutions as permanent as real film and proof sheets, but maybe these discs will last until a better answer comes along.
Posted by: CARL WEESE