KB73058442: ArtProThe Densitometer shows 50.2% for 50% screen

Summary

From ArtPro 12.0.0 onwards, the Densitometer shows 50.2% for 50% screen.

Why?

ArtPro works internally with 255 grey values, equally spread between 0 and 100%. This way, the possible values for densities are (rounded to 0.1%) 0, 0.4%, 0.8%, 1.2% until 99.6%, 100%.  In older versions than ArtPro 12, these values were shown rounded off to 1%, meaning that you could not see the difference between 0 and 0.4% (both shown as 0%) and between 0.8 and 1.2 % (both shown as 1%). Specifically the inability to see whether there is a little dot or no dot at all was problematic, most certainly for flexography. Therefore we now show densities rounded off to 0.1%.

When you enter a density like 50%, it will first pick the closest grey value, which is value 128 on a scale of 255 (this has always been the case). This is then shown as percentages, which is 128/255 = 0.5019. Previously this was shown as 50% (rounded off to full %), now it is shown rounded off to 0.1% as 50.2% (which is a more accurate representation of the truth).