Ajax Portfolio image quality

Hello,

I have problem with my ajax portfolio. My page is http://tinyurl.com/lzxgk7q. So I have 3 columns ajax portfolio when i click on first thumbnial we see opening portfolio big image with thumbnial above . Image size in gallery is 650×805 but looks not good poor quality, When you click on it in lightbox that image looks very good (size is extactly the same)

And second problem after upgrade wordpress when you resize window to 320px lightbox looks not good

Best Regards
Michal