Apologies, just spoke to Kyle and clarified what you were referring to. The 600px width is set by the theme, you can change it by changing /woocommerce/single-product/product-image.php line 18, or adding this filter to a child theme functions.php file:
function custom_product_image_width() {
return 800;
}
add_filter('sf_product_image_width', 'custom_product_image_width');
– Ed