Not sure if this really belongs in the LR forum, but since I printed out of LR...
Can anyone help me to understand this. I printed an H3D-39 file on A2 - Ilford Gold Fibre Silk. LR showed it at 348ppi at approx 15x19 inches so I picked the resolution as 360. The image contained large areas of smooth toned sky and a metal wall. The print however showed a sort of "waffle" effect over the smooth areas - as if someone had stamped all over it with a waffle iron. This wasn't particularly strong but was very noticeable.
I finally realised what was causing the problem - I was printing from a Tiff file that I had, most probably, exported from LR some time ago and which included some sharpening (most probably in the region of 65,1,25 - which looks pretty good at 100% on screen). Before printing the .tiff I applied much the same sharpening again in LR. Removing the extra sharpening resolved the problem and the file printed beautifully with clean, smooth tones.
Curiously looking at the file at both 100% and 200% showed no indication that it was over-sharpened. The sky and wall areas looked clean and showed even "grain". Why should this additional sharpening have caused this effect? Sharpening has always been a bit of a mystery to me,but this was not a case of the sharpening causing halos around edges - it completely muddied what should have been a smooth tone with no detail in it.
Any explanations?
Can anyone shed any light on