I used to take photos in the largest file option before the RAW option and never had problems opening or previewing the pix. Now I'm shooting in RAW. My photos look great in my camera viewfinder. However, when I try to open them on my computer (using Picasa 3) each photo has something VERY VERY wrong - large distorted blocks, bright colored streaks, etc. It looks like a problem with opening the pix to preview. Why is this happening? What software should I be using to preview photos? I'm not tech savvy and am afraid to do anything and lose the priceless pix of my son's first prom. HELP!


1 Answer 1


Just so you know:

  • What you see on your camera is the embedded thumbnail in the RAW file.
  • What you see on the computer is the software's interpretation of the RAW file.

Most likely, your files are fine but the software is having trouble decoding the RAW files from your camera. This is a regular occurrence since RAW files are different between cameras. Most software get regular updates to support new RAW formats. Check if your Picasa is at the latest version if you want to use them. Upgrade if it is not and try again.

Otherwise, the most reliable bet is to use software provided with your camera. There is always one on CD. The interface is often poor but it is the most compatible. If your camera is particularly new, which it could be since very few RAW-capable cameras can show images in the viewfinder, this will be the only software capable of understanding your RAW files for a short while. When a new camera comes out, software can take anywhere from several weeks to several months to catch up.

  • \$\begingroup\$ I have a Canon EOS Rebel XSi 450D. I installed the software that came with the camera and used ZoomBrowser EX to open the pix. Almost all were fine but there are about eight that are still a mess. The camera is working fine. The SD card is new. How to fix these eight? These photos are still perfect in preview so I think it's a software problem but not sure what else to do. \$\endgroup\$
    – Sharalyn
    May 5, 2013 at 3:03
  • \$\begingroup\$ Note that I said most likely. The two first statements are key. The preview is showing an embedded thumbnail not the RAW data since it has not been developed yet. Therefore it is unfortunately possible that the RAW data is corrupted but the thumbnail is not. For a way to extract that, refer to this question. Also note that what you see in the viewfinder is not the image stored in the camera but what it is in front of your lens since the XSi is an SLR. \$\endgroup\$
    – Itai
    May 5, 2013 at 3:46
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    \$\begingroup\$ @Sharalyn (Cont'd). Since all but eight seem to work, it is likely you have a corrupted card. It does not matter if the card is new or not, some are just poor quality or defective. If you value your images, make sure you use a high quality card (SanDisk black or red, not blue, Lexar and Kingston to name the most reputable ones). \$\endgroup\$
    – Itai
    May 5, 2013 at 3:48

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