JPEG vs RAW

[captpackrat]

My camera can take save images as both JPEG and RAW at the same time. In this example, the JPEG is on the left and the RAW on the right.

JPEGs save much faster, take up much less space, are usable just as they are, can be opened by just about anything and Windows can automatically display a thumbnail of the image. The biggest drawback of JPEG is that it is a lossy format, and working with a JPEG just makes things worse.

RAW files, on the other hand, contain the unprocessed data directly off the image sensor. They are higher quality, offer finer control, are generally 12 or 14 bit (vs JPEG's 8 bits) and are lossless. The drawbacks are its enormous file size (7 times larger than JPEG on my camera) and a proprietary format that might be difficult to open in the future.

In this particular image, notice the sky is a truer blue, there is more contrast in the clouds, the ground haze is more visible, the tractor wheels and clouds are whiter and the grass a bit greener on the RAW side.

Comments

[rustitobuck.livejournal.com]

The difference in the color saturation is more likely due to a difference in the presumed color profile of the two images, or the profile stored in the image. Either that, or the camera did some processing before making the JPEG. It could be that the response curves of the sensor are not linear, and so the camera is correcting to probably sRGB before compressing.

[captpackrat.livejournal.com]

The camera has a handful of AWB profiles it can select from, either automatically or manually, that it uses to create the JPEG. If it chooses incorrectly, you can fix it later in software, but you're still working with an already lossy-compressed JPEG. It also has noise correction and other routines it runs through when creating the JPEG. The RAW file does none of this, leaving it to the user to select the best options during "development".