Hello Jeff,
many thanks for your answer !
I hope that Eric will read here and give us some additional information. In my opinion, decconvolution sharpening is the much better way than increasing the edge-contrast as done by any other way.
That would be great, though I also recognized that all images in the first 3 chapter - and so I assume in the following chapter as well, are a little unsharp and blurry. The strange thing is that it applies just to the images, not to the screenshots made from Lightroom or ACR, they are tacksharp.
Ah, I'm talking about the Kindle ebook.
Robert