whenever I zoom in on an image to view it closer, the picture suddenly becomes very grainy right before it zooms in. Anyone else have this issue?
Yes- I see it also, but only very briefly. (CC2015.9 Windows-10)
I presume it is related to Lightroom's method of re-creating previews of different sizes in the preview cache.
Also it would depend on the speed of you system to re-read the original image when Lr has to create a preview of a different size.
Retrieving data ...