Hi,
In the HikaShop configuration, you can first set restriction for the image maximum size (image width & image height)
See:
www.hikashop.com/support/support/documen...fig.html#main_images
It will unsure you that your vendors won't try to upload too big images ; if so, they will be reduce dynamically.
After that, yes, the "force size" option in a product listing will help you to have always thumbnails with the same dimension ; but it will be in a product listing, the product page will stay the same.
But there is no setting or no restriction for the minimum upload image size in HikaMarket ; regarding your tests in your website I think it might be a good idea to add such kind of option.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.