These little lovelies are called daguerreotypes (though sometimes tintypes were put under glass to achieve the same affect cheaper). Startlingly enough, the photos were often much sharper and clearer than this. You can sometimes count the buttons on a vest in a picture taken nearly 150 years ago.
History teaches us (ala The infamous "butch cassady and the wild bunch" photo) that wanted men and gamblers with shady pasts shouldn't have their picture taken. Let's just hope no one recognizes them!