product detail pop up image size

I’m sure this has been asked but I can’t seem to find an answer …

I’m trying to upgrade to 2.0 from 1.3.5. My images are too large for the pop up. I’ve been manually redoing the images in bulk via photoshop, but honestly this is going to take HOURS. To my dismay, when I added additional images, the photo got cut off again (and by the time I resized to fit with additional images, it was really not much larger than the thumbnail…).

Is there a way to mod the cart so that the images auto fit into the window? TIA