I have 2 very simple pdf files that contain just the letters "ABC". In the first file the font is fully embedded and in the second file the same font is subset embedded. When both files are viewed in Adobe Acrobat, I noticed that at lower zoom levels (125% or less) the subset embedded font looks appears to be lighter than the fully embedded font. However, at higher zoom levels (150% or more), both fonts appear to look the same. I have compared the font tables of the two documents and was unable to find anything that looked like it could explain this behavior. How does Adobe render the fonts in this file at different zoom levels? And what font tables are relevant to Adobe when zooming in and out?