One of the favorite claims of people who prefer to work with raw image files rather than JPEG image files is that they have greater ability in fixing a bad image during the "raw development" process on the computer.
They point to the ability to fix "blown highlights" -- areas of the picture where detail has washed out to a dead white. Many demonstrations of this ability start with a picture that seems unrecoverable, but is rendered usable during the raw processing. They claim that this sort of recovery is impossible with JPEG images. But maybe there's a way to do this with JPEGs as well.
In the test below, I set my Panasonic DMC-FZ28 to "RAW + JPEG." Every time I press the shutter, I get a raw file and JPEG as well, making this comparison easier. I should point out, however, that the JPEG produced at this setting will be "Standard" quality, rather than "Fine," so imagine that the JPEG might be a little better than you see here.
Here we go.
How was the JPEG restored? Simple. The same way as the raw file -- I used Adobe Camera Raw. Here's how:
First, you'll need either Photoshop or Photoshop Elements. If you have neither, get Photoshop Elements. It has a street price of about $60 and it's worth it for this alone. Adobe Camera Raw is included with these programs, but you'll need the very latest version to process the raw files from the DMC-FZ28. However, almost any version will work with JPEGs. (You can get the very latest version of Adobe Camera Raw from the Adobe web site. There's no charge for this.)
The next puzzle is how to open a JPEG file in a program meant for processing raw. Here's what to do:
1. Open Photoshop or Photoshop Elements.
2. Under the "File" menu, select "Open As..." You will see the "Open As" dialog box.
3. Select "Camera Raw" from the lower list box.
4. Navigate to your JPEG file and select it. Click the "Open" button.
Now you should be in Adobe Camera Raw, ready to fix your JPEG file.
Adjust the "Exposure" and "Recovery" sliders until you see the missing detail restored. This may take some practice. Try to keep these adjustments to a minimum as they affect the entire image and overdoing could make the rest of the picture too dark.
After you're done with these adjustments, click the "Open Image" button at the bottom of the window and you will now be in the photo editor where you can finish with whatever editing the picture needs.
Whenever I'm finished with editing an original JPEG image, I always save it as a TIFF file, so nothing is lost. You can select to compress the file, which will save some disk space.
And that's it. Highlight detail restored in a JPEG image. And one less reason for shooting raw.
Note: Don't expect miracles. There's only so much that can be recovered using this technique, but it will match raw in the amount of highlight detail that can be saved.
Note: the term "blown highlights" is a favorite among folks who shoot raw. Your favorite search engine will turn up lots of references that will provide interesting reading. There is some disagreement as to the actual meaning of this term.
Note: Since I started working with digital cameras, and since it's easy to get every shot into the computer, I have a policy of never throwing anything away. Who knows when there will be a software answer to that picture you thought was destined for the trash can?