Lossy compression of raw data is currently the only option available in Sony cameras of series NEX, SLT, RX, ILCE, ILCA, and the recent DSLR-A.
The first part of this article is showing how to detect artifacts caused by this compression. We will be discussing the technical details of this compression in the second part of this article.
In the vast majority of cases, the compression artifacts are imperceptible unless the heavy-handed contrast boost is introduced. There are, however, exceptions. With some unlucky starts in alignment, the artifacts can become plainly visible, even without much image processing.
All that is necessary for the artifacts to threaten the quality of the final image is a combination of high local contrast and a flat featureless background.
Lets have a look at the example, which was first published by Lloyd Chambers in his blog.