While trying to understand those processing effects that are most destructive to JPEG, I returned to this series of articles.
http://www.ronbigelow.com/articles/raw2/raw2.htm
Obvious first consideration is to minimise the squares from compression. I have now resorted to looking at the TIFF and JPEG at
5,000% ie each pixel is 10mm square on my screen and I cannot find the effect described here.
Why is the obvious question. Any clues ?
Don