Bad Raw File - Camera or Card?

[mark.brennan]

<p>Hi All - </p>

<p>I took some pics today and after uploading I noticed 2 of the captures had corrupted files - this is the first time I've ever experienced this. I have a 5D MkI, which I bought used over a year ago and have gotten very good use from, with no issues.</p>

<p>I shoot raw and neither the camera preview nor the preview in Lightroom shows the problems with these two frames until I've imported (converting to DNG, as is my custom).</p>

<p>I'm wondering if anyone has any insight into whether this could be an issue with the sensor, or with the card (the card is a SanDisk Ultra 8GB 30MB/s)? What's scary is the problem didn't manifest until after import; some days I'll shoot 100+ frames, and I'd hate to find that some choice shots were corrupted. Today's problem only occurred with 2 of about 26 frames.</p>

<p>Any feedback appreciated - thanks!</p>

<p>Regards,<br>

-Mark<br>

Bad Raw File #1 - a portion of the frame corrupted with color banding:<br>

<img src="http://d6d2h4gfvy8t8.cloudfront.net/14294298-lg.jpg" alt="" /></p>

<p>Bad Raw File #2 - a portion of the frame completely whited out:<br>

<img src="http://d6d2h4gfvy8t8.cloudfront.net/14294297-lg.jpg" alt="" /></p>

[g dan mitchell]

<p>I cannot say for sure, but I'd bet on an issue with the card. Do you reformat the card in the camera every time to delete the previous photographs? You could try reformatting it and using it again - preferably on a subject that isn't too precious.</p>

<p>Or you could just get a new card.</p>

<p>Dan</p>

[Spearhead]

<p>You can buy another card for under $10 and try it. You can also take the card this happened with to a camera store and use a different camera, or use a friend's camera. This kind of testing is simple and cheap, you should do it before asking since nobody here will know absolutely.</p>

[peter_mckone]

<p>Was the corruption maybe introduced during the conversion to DNG?</p>

[mark.brennan]

<p>Dan and Jeff - </p>

<p>Thank you both for your replies. Indeed I did test the card but have not been able to reproduce the problem (although I have not tested it in another body, which is a good idea). I have a number of other Sandisk 8GB cards so I think I'll put this one on the "back shelf". Although I always deleted files I've uploaded, I realize I have not reformatted the card, so I'll do that in the future.</p>

<p>Thanks again.</p>

<p>Regards,<br>

-Mark</p>

[mark.brennan]

<p>Dan and Jeff - </p>

<p>Thank you both for your replies. Indeed I did test the card but have not been able to reproduce the problem (although I have not tested it in another body, which is a good idea). I have a number of other Sandisk 8GB cards so I think I'll put this one on the "back shelf". Although I always deleted files I've uploaded, I realize I have not reformatted the card, so I'll do that in the future.</p>

<p>Thanks again.</p>

<p>Regards,<br>

-Mark</p>

[peter_e]

<p>It may be the file transfer from your card to the computer. Delete the raw file from your computer and copy the file from your card again. If the file looks ok then, it is could be your antivirus realtime scan that interfers with the transfer. Turn off your antivirus while you transfer your data.</p>

[g dan mitchell]

<p>"I realize I have not reformatted the card..."</p>

<p>Use the camera's card formatting setting to delete the images from the card each time.</p>

<p>Dan </p>

[zml]

<p>I'm with Peter E on this one: unless the pins are dirty (dust, mosture!) or loose, it might be the transfer from camera. Try to tranfer the corrupted images again using a different method (such as an external reader) and see what happens. If the corruption persist it is either the card or the camera.</p>

 

[photodiscoveries]

Had a similar happening on my 7D. Same look...several weeks later, while travelling, the camera locked up and did not

shoot anything. Back to Canon and they said the shutter had locked and had to be replaced. Do not know if the two

happenings were related, but have never had the issue again. For whatever the thought may be worth, it might be

worthwhile calling Canon tech support. They have been very helpful answering questions without charge.

[paddler4]

<blockquote>

<p>Although I always deleted files I've uploaded, I realize I have not reformatted the card</p>

</blockquote>

<p>Reformat the card (using the camera) each time, after uploading the images. Some people argue that deleting images individually while in the field can also lead to corruption, but I have never had that experience. I simply reformat the card in the camera every time I upload. I have been using the same SanDisk card well over 90% of the time for two years without a hitch.</p>

[jpk]

<blockquote>

<p>neither the camera preview nor the preview in Lightroom shows the problems with these two frames</p>

</blockquote>

<p>What about converting RAW to JPG using Canon software?</p>

[jim_larson1]

<p>I don't think I have EVER reformatted a card in any of my digital cameras, P&S's or DSLRs. </p>

<p>Sure. . .it can't hurt. But unless you actually have corruption issues, you simply don't need to reformat cards after every use. The "delete" function in Explorer works just fine.</p>

<p>I can't speak to using the in-camera delete functions, as I generally use external card readers to transfer data and remove images.</p>

 

[craig_meddaugh]

<p>There are dozens of things that can cause bit corruption. Bad card, bad read of good card, good read of good card that was written to a bad sector on a hard drive. Good read of good card written to a good sector but garbled by the kernel during the transfer process... the list goes on and on. </p>

<p>The reason you don't see the problem in lightroom or the camera is because both of those show a jpeg image generated when you take a photograph, so the corruption of the underlying raw image isn't shown. Of course, it could be that your DNG converter screws up once in a while (very possible). </p>

 

[mark.brennan]

<p>Hey Everyone - </p>

<p>Many thanks to all for the responses. Fortunately, I have not seen this problem again (although I have temporarily "retired" the card which exhibited the problem). I am now re-formatting cards after each use. I totally get the many parameters and permutations of the problem and my chief concern at the time was whether the camera was the culprit. Unless I see the issue again I'll assume it was the card.</p>

<p>Thanks again.</p>

<p>Regards,<br>

-Mark</p>