focusfirm wrote in post #18022509
Actually, I bought additional CFast cards from B&H - 128GB ones. That is where I am seeing the issue. I don't use the little one that came with it much. I agree that bad cards are a possibility, but in 12 years of using SanDisk Extreme Pro products, I have never had an issue. But this is indeed a new technology. The question becomes how do we determine a card is bad? If I can full-format it without error and have some shoots go without error and not have a problem mounting or copying files from the card, what is the likelihood then that it is the card? I am very open to this possibility, but how do I PROVE the card is bad when I get no actual errors using it other than the some of the RAW files having that funny rectangle? And isn't it peculiar the consistency of it always being a rectangle of garbage in the lower right hand corner and nothing else? Maybe someone familiar with the internals of the RAW file can comment on that.
Short of shooting a bunch (to generate your 1-5% write fail rate), it's hard to say. I would recommending shooting the next 1000 or so photos with the 64gb supplied in the premium kit (also writing to your CF as back-up just so you don't screw up an important photo) and see if the problem shows up on the 64gb CFast. If not, then the 128gb is bad.
I've been shooting with CF cards since 2004. I've only ever encountered 1 bad card, but they do happen as well. The card formatted fine and didn't show any errors. The only reason I know it would be a bad card is when a very few images kept being written wonky/funny on it.
If it turns out to be the CFast card, I think you can then make a case with B&H customer service to let them know they sold you a bad card and want an exchange. B&H customer service (via phone) is usually very accommodating.
HOWEVER, if the 64gb also gives you these messed up RAWs, then in your situation, it might be the camera's internal CFast slot that's the issue.