Jpeg Images Compression

Go to System → Settings → System

Set .jpeg images quality level for new thumbnails generation. Best quality, biggest file. There is no single "best" JPEG compression setting, and depending on the type and complexity of image detail (or lack of complexity and detail), you may find yourself using 40-60, 70-80, or 90-100 as appropriate for the product photos.

retina images

to make your images crisp automatically turn on Hi-res images setting