Since releasing the theme, we've found a way to make the images clearer. Most stores are fine (even with the older version of the theme), but if you find your images are bit fuzzy, here's a quick way to increase their resolution:
1. Go to Admin > Themes > Template Editor. Open up "settings.html" down the bottom, under configs. Make a backup of this file before you change it.
2. Do a ctrl+F to Find the text "870". You should see "max-data-width: 870" several times, once for each slideshow image setting. Change this 870 to 1170 instead, for all of them. Now, if you do a search for 870, no results should come up. They should all be changed to 1170.
3. Lastly, upload images of 1170px wide x 420px tall, via your Theme Settings.
They should now be really clear.