Deleting files in camera
An article on "The Online Photographer" caught my eye. Called "To Delete or Not, That Is the Question..." by Carl Weese, it discusses the merits of deleting images in camera. However, the article deals with it from the point of view that you may make mistakes and get rid of images that you would later (or sooner) regret loosing. It is worth reading*.
But there is another aspect to this. Some photographers will already have experienced card errors in the past. Times when the camera and card don't seem to want to talk to each other. When this occurs the normal practice is to turn the camera off and back on again (and if that doesn't work try removing the battery and even the card and after a short pause putting them back). The problem is that some of your images may be corrupted, most likely with the last one taken before the error. Another aggravation may be that you were in a situation where things were happening around you, and you were not able to capture them because of sorting out your cameras little huff. For most people these occurrences are very rare, but can be a nuisance none the less.
It may sound strange, but deleting images in camera may increase the likelihood of card errors. Here's why. Images (files) are written to the card in order and the space on the card is used in a particular "write order" - just as we write from top left to bottom right. If an image is deleted it leaves a space. When the next image is written to the card the space is filled. Fine, but what happens if this new file is bigger (quite possible because of variable file compression that can compress plain images more that images with a lot of detail). The file is split, and now part of it fills the space left by the deleted image and the rest goes to the end. This results in fragmentation and makes the card harder and slower to read.
My suggestion is that if you don't have enough room for the images you want to take, you simply buy a bigger card. These days they are cheap enough (but see my previous piece on buying cards on eBay). To clear the card completely, use the "Format" option on your camera.
*In Carl Weese's piece he refers to a previous article. I couldn't find it, but if you do and I am repeating what is in it, I apologise for the duplication.
The panoramic above is not an image from this winter, but taken in Denham - within a mile of my home - a few years ago. Six frames stitched together.