Happens on both my Macbook Pros, too - a early 2015 13" (i7-5557U) with Sierra, and a mid 2014 15" (i7-4980HQ with discrete GPU) with High Sierra. The symptoms for me, with the proviso that I'm not in OS X right now to double check:
1. set Preview to open PDFs at 100% zoom, 1 page at a time. Open a PDF. Preview opens the window at the right size, then pops some scrollbars in. Now the client area is smaller, and that means the window is the wrong size! - which means the mouse wheel scrolls the view, rather than scrolling from page to page. Gets me every damn time.
(This could be related, I imagine, to that setting that forces scrollbars always to be displayed. I suppose it's too much to expect Apple's QA to have a test matrix that encompasses this case)
2. scroll from page to page. Each new page appears blurry - or, if lucky, merely wonky - for a fraction of a second, then replaced with the clearer rendering one might expect. Actually quite distracting when scrolling page by page! - and when scrolling at keyboard repeat rate, the clearer version never has time to appear, making it impossible to scroll through a document visually at full speed
3. when resizing the Preview window, some sizes look mucky - looks like the sort of thing you get if you render to an offscreen buffer that's 1 or 2 pixel the wrong size, or add the 0.5 to only one edge of your quad, and so on. Really annoying
THIS drives me nuts.
I have this issue on a 2012 and 2015 MBP as well as on a MP 5.1. With the built in screens, Eizos and a NEC SV. The only thing thats common across all builds is the OS.
If you think you dont have this issue, compare the rendering of Preview.app at 100% with that of Acrobat.
> At 100% zoom level, the type is not rendered with crisp edges. It looks as if someone had applied a mild gaussian blur. Only once you zoom in, the outlines are sharp as they should be.
a number of times.
Running on a 12" (Retina) Macbook w/ macOS 10.13.4 and Preview 10.0 (944.5).
1) Here's a screenshot (100% on left, zoomed in on the right) - https://s3.amazonaws.com/citruspi-tmp/Screen+Shot+2018-06-01...
2) PDF being used - https://cdn.beastnet.works/bfc7d34daac8e7630541d49b591b1b62/...
It also happens within the PDF viewer in Safari - text and icons look a lot crisper when zoomed in.
https://image.ibb.co/hXi53J/screenshot.png
15 inch MBP.