page width post page/opacity posts

First of all, great theme! Thank you so much. Few questions..

1. If I set latest post on front page then the image sizes are bigger than when I set the front page a static page and another page the post page. Can I somehow set the images to be the same as when the post page to be on another page than the front page? Hope that makes sense?

2. The roll over feature is great, just one questions, can I somehow set opacity so the image can still be seen in the background when hovering over the post?