Canon Powershot G7 "Unidentified image"

On Mon, 24 Nov 2008 23:38:47 -0800 (PST), Bengt T
wrote:


I have tried more than 5 different brands of SD cards with the same
result ("Unidentified image" appearing from shots starting from
picture no 257). The significance (..from picture 257..) makes me
assume that there is a fundamental problem in the camera to write into
the SD card from a certain memory location.

Please note that this, in my case, only occurs in bracketing mode, 3
pictures in a sequence shoot and written into the SD card. I have, so
far..., not noticed any problem with single shots. Could, in my case,
indicate that the writing procedure by the camera is unreliable into
SD memory area from picture 257, when many pictures, 3 in my case, is
stored in a rather rapid sequence.

/Bengt

This sounds like a card's write-speed problem. Are you buying the more
inexpensive slowest cards? After so many images a card's data-structure can make
write-time even slower, greatly cutting into those slower-card's already slow
write-times.

Try a faster card, borrow one if you can just for testing.

I would also carefully clean those internal contacts on the camera. A bit of oil
on one of them might be preventing complete contact. During more rapid
file-saving operations the card's check-sum routines, when re-trying to write
erratic data, could be causing the errors. Use a cotton swab dampened with some
isopropyl alcohol and clean those contacts, being careful to not leave any stray
cotton strands behind.